Malevolent Designer News - The Sneaky Way Chlamydia Is Designed To Get Round The 'Problem' of Antibiotics

Immunofluorescence staining of human gastric cells grown in a microplate and infected with Chlamydia trachomatis.
Blue: cell nuclei, green: C. trachomatis, grey: actin.

Image: Pargev Hovhannisyan / Universität Würzburg

Chlamydia doesn’t always cause symptoms, but when it does, these are some of the most common.

Everyday Health

Chlamydia Can Settle in the Intestine -

Chlamydia is a sexually-transmitted bacterial infection in which the bacteria are passed to a new victim during sexual intercourse. It caused few or no symptoms to begin with - usually nothing worse than mild itching - but if left untreated it can cause infertility and sometimes cancer. Fortunately, it can be treated successfully with antibiotics.

However, it is not unusual for people who have been successfully treated to develop a new infection with exactly the same strain as the previous infection, suggesting that the bacteria had somehow survived the antibiotic treatment although symptoms had disappeared, and traces of the bacteria had gone.

Researchers have now shown that chlamydia can take up residence in the gut where it can survive for some considerable time and develop increasing resistance to antibiotics with each course of treatment. The mechanism of this increasing resistance is a classic example of evolution as the antibiotic acts as an environmental selector which removes the non-resistant bacteria from the population gene pool, leaving the resistant form to become dominant in the gene pool.

Refuting Creationism - The Choanoflagellates Of Mono Lake Show How Multicellular Organisms Evolved

A 3D reconstruction of a spherical colony of 70 choanoflagellates from the newly-named species Barroeca monosierra discovered in Mono Lake.

Davis Laundon and Pawel Burkhardt,
Sars Centre, Norway;
Kent McDonald and Nicole King, UC Berkeley

Creature the size of a dust grain found hiding in California's Mono Lake - Berkeley News

Mono Lake, located east of the Sierra Nevada, just outside Yosemite National Park. Dotted with tufa formations, the lake’s salty water is laced with arsenic and cyanide, but is home to unique flies and brine shrimp as well as choanoflagellates.

Nicole King.

To be fair to them, the simple pastoralists from the ignorant and fearful infancy of out species who invented the creation myths that got included in the Bible, later decreed to be the inerrant word of a creator god and therefore deemed to be real science and history, could have known nothing of Mono Lake in Present day California and even less about the microscopic organisms about the size of a dust grain known now as choanoflagellates because, quite simply they lacked the technology to be able to see them - which is also why neither cells nor micro-organisms are mentioned nor even hinted at, anywhere in the Bible.

What are choanoflagellates and how do they relate to other organisms? Choanoflagellates are a group of free-living, single-celled organisms that are considered to be the closest living relatives of animals (metazoans). They are part of the clade Opisthokonta, which also includes fungi, animals, and some protists. Here’s a closer look at what choanoflagellates are and their relationship to other organisms:

Characteristics of Choanoflagellates

• Structure: Choanoflagellates are characterized by a distinctive cell structure. Each cell has a single flagellum, which is a whip-like structure used for movement, surrounded by a collar of microvilli (tiny, finger-like projections). The flagellum beats, drawing water through the collar, which traps bacteria and other small particles for the choanoflagellate to feed on.
• Habitat: These organisms are commonly found in aquatic environments, including both freshwater and marine ecosystems.
• Lifestyle: Choanoflagellates can exist as single cells, but some species form colonies. Their colonial forms are of particular interest because they offer insights into the possible evolutionary steps that led to multicellularity in animals.

Relationship to Other Organisms

• Closest Relatives to Animals: Genetic and molecular studies have shown that choanoflagellates are the closest living relatives to animals. This means that they share a common ancestor with animals, which is believed to have lived over 600 million years ago.
• Evolutionary Significance: The relationship between choanoflagellates and animals is crucial for understanding the origin of multicellularity. It is thought that the transition from single-celled to multicellular organisms may have occurred through mechanisms similar to those seen in choanoflagellate colonies. The study of choanoflagellates helps scientists understand the early evolution of animals and the development of complex tissues and organs.
• Shared Genes: Choanoflagellates possess many genes that are also found in animals, including those involved in cell adhesion, signaling, and extracellular matrix formation. These genes are essential for the development and maintenance of multicellular structures in animals, suggesting that the genetic toolkit required for multicellularity was already present in the last common ancestor of choanoflagellates and animals.

In summary, choanoflagellates are not only fascinating in their own right as unique protists, but they also play a key role in understanding the evolutionary steps that led to the rise of the animal kingdom.

And, being unaware of the history of life on a planet that they thought was only a few thousand years old and had been created out of nothing by magic with all the animals and plants fully formed, they could never in a million years, have guessed how multicellular animals evolved several hundred million years ago out of colonies of single-celled organisms.

And, of course, it's the yawning chasm between what the Bible's authors believed and what we now know, that tells us the Bible can't be the work of an omniscient creator god.

But of course, there are still a few (shrinking) gaps in what we know too. For example, although we have the genetic and structural evidence that multicellular organisms evolved out of single-celled organisms, we don't yet know the precise details, which is why a team of researchers from University of California, Berkeley have been studying a little-known choanoflagellates found in Mono Lake, near the Sierra Nevada, California. choanoflagellates are known to form colonies of organisms so can help shed some light on how related organisms originally got together to form simple multicellular organisms.

An additional discovery of this research was how these colonies incorporate a bacterial biome in a process analogous to the way most multicellular animals have associated biomes like out gut biome, for example.

The Berkely team's work is the subject of an open access paper in the American Society for Microbiology (ASM) journal mBio. It is also explained in a University of California Berkely news release:

Creature the size of a dust grain found hiding in California’s Mono Lake

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Colonies of these choanoflagellates — members of a group considered to be the closest living relatives of all animals — have their own unique microbiomes.

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Mono Lake in the Eastern Sierra Nevada is known for its towering tufa formations, abundant brine shrimp and black clouds of alkali flies uniquely adapted to the salty, arsenic- and cyanide-laced water.

University of California, Berkeley, researchers have now found another unusual creature lurking in the lake’s briny shallows — one that could tell scientists about the origin of animals more than 650 million years ago.

The organism is a choanoflagellate, a microscopic, single-celled form of life that can divide and develop into multicellular colonies in a way that’s similar to how animal embryos form. It’s not a type of animal, however, but a member of a sister group to all animals. And as animals’ closest living relative, the choanoflagellate is a crucial model for the leap from one-celled to multicellular life.

Surprisingly, it harbors its own microbiome, making it the first choanoflagellate known to establish a stable physical relationship with bacteria, instead of solely eating them. As such, it’s one of the simplest organisms known to have a microbiome.

Very little is known about choanoflagellates, and there are interesting biological phenomena that we can only gain insight into if we understand their ecology.

Professor Nicole King, senior author
Professor of molecular and cell biology
Howard Hughes Medical Institute and Department of Molecular and Cell Biology
University of California, Berkeley, California, USA.

Globular colonies of the choanoflagellate B. monosierra seen under a microscope. As indicated by the 50-micron scale bar, these colonies are at the limit of what’s visible to the naked eye.

Alain Garcia De Las Bayonas, Nicole King lab.

Typically visible only through a microscope, choanoflagellates are often ignored by aquatic biologists, who instead focus on macroscopic animals, photosynthetic algae or bacteria. But their biology and lifestyle can give insight into creatures that existed in the oceans before animals evolved and that eventually gave rise to animals. This species in particular could shed light on the origin of interactions between animals and bacteria that led to the human microbiome.

Animals evolved in oceans that were filled with bacteria. If you think about the tree of life, all organisms that are alive now are related to each other through evolutionary time. So if we study organisms that are alive today, then we can reconstruct what happened in the past.

Professor Nicole King.

King and her UC Berkeley colleagues described the organism — which they named Barroeca monosierra, after the lake — in a paper published online Aug. 14 in the journal mBio.

A beautiful colony

Nearly 10 years ago, then-UC Berkeley graduate student Daniel Richter came back from a climbing trip in the Eastern Sierra Nevada with a vial of Mono Lake water he’d casually collected along the way. Under the microscope, it was alive with choanoflagellates. Aside from brine shrimp, alkali flies and various species of nematode, few other forms of life have been reported to live in the inhospitable waters of the lake.

The newly named species Barroeca monosierra discovered in Mono Lake. Colonies of these organisms consist of numerous identical cells (cyan), each with flagella (green) that allow them to propel themselves through the water. This choanoflagellate colony hosts its own microbiome (red), something never before seen in these organisms. The extracellular matrix with which the bacteria interact is shown in white.

Video credit: Davis Laundon and Pawel Burkhardt, Sars Centre, Norway; Kent McDonald and Nicole King, UC Berkeley.

It was just packed full of these big, beautiful colonies of choanoflagellates. I mean, they were the biggest ones we’d ever seen.

Professor Nicole King.

The colonies of what seemed to be close to 100 identical choanoflagellate cells formed a hollow sphere that twirled and spun as each individual cell kicked its flagella.

One of the things that’s interesting about them is that these colonies have a shape similar to the blastula — a hollow ball of cells that forms early in animal development. We wanted to learn more about it.

Professor Nicole King.

At the time, however, King was occupied with other species of choanos, as she calls them, so the Mono Lake choanos languished in the freezer until some students revived and stained them to look at their unusual, doughnut-shaped chromosomes. Surprisingly, there was also DNA inside the hollow colony where there should have been no cells. After further investigation, graduate student Kayley Hake determined that they were bacteria.

A colony of choanoflagellates stained to show its features. Cyan indicates DNA — the doughnut-shaped DNA of the choanoflagellate cells and a cloud of bacterial DNA inside the colony — while flagella are white and microscopic hairs (villi) on each cell are red.

Kayley Hake, Nicole King lab

The bacteria were a huge surprise. That just was fascinating.

Professor Nicole King.

Hake also detected connective structures, called extracellular matrix, inside the spherical colony that were secreted by the choanos.

Only then did it occur to Hake and King that these might not be the remains of bacteria the choanos ate, but bacteria living and grazing on stuff secreted by the colony.

No one had ever described a choanoflagellate with a stable physical interaction with bacteria. In our prior studies, we found that choanos responded to small bacterial molecules that were floating through the water, or [that] the choanos were eating the bacteria, but there was no case where they were doing anything that could potentially be a symbiosis. Or in this case, a microbiome.

Professor Nicole King.

King teamed up with Jill Banfield, a pioneer in metagenomics and a UC Berkeley professor of environmental science, policy and management and of earth and planetary science, to determine which bacterial species were in the water and inside the choanos. Metagenomics involves sequencing all the DNA in an environmental sample to reconstruct the genomes of the organisms living there.

After Banfield’s lab identified the microbes in Mono Lake water, Hake created DNA probes to determine which ones were also inside the choanos. The bacterial populations were not identical, King said, so evidently some bacteria survive better than others inside the oxygen-starved lumen of the choanoflagellate colony. Hake determined that they were not there accidentally; they were growing and dividing. Perhaps they were escaping the toxic environment of the lake, King mused, or maybe the choanos were farming the bacteria to eat them.

Much of this is speculation, she admits. Future experiments should uncover how the bacteria interact with the choanoflagellates. Past work in her lab has already shown that bacteria act like an aphrodisiac to stimulate mating in choanoflagellates, and that bacteria can stimulate single-celled choanos to aggregate into colonies.

For her, the Mono Lake choanoflagellate will become another model system in which to study evolution, just like the choanos that live in splash pools on the island of Curaçao in the Caribbean — her main focus at the moment — and the choanos in pools at the North and South Poles. It might be a challenge to get more samples from Mono Lake, however. On a recent visit, only six of 100 samples contained these energetic microorganisms.

I think there’s a great deal more that needs to be done on the microbial life of Mono Lake, because it really underpins everything else about the ecosystem,. I’m excited about B. monosierra as a new model for studying interactions between eukaryotes and bacteria. And I hope it tells us something about evolution. But even if it doesn’t, I think it’s a fascinating phenomenon.

Professor Nicole King.

In addition to King, Banfield, Hake and Richter, UC Berkeley co-authors of the paper include former doctoral student Patrick West, electron microscopist Kent McDonald and postdoctoral fellows Josean Reyes-Rivera and Alain Garcia De Las Bayonas. The work is supported by HHMI and the National Science Foundation.

• A large colonial choanoflagellate from Mono Lake harbors live bacteria (mBio)
• Newly Discovered Microorganisms Band Together, ‘Flip Out’ (2019)
• Bacteria act as aphrodisiac for the closest relatives of animals (2017)
• Did bacteria spark evolution of multicellular life? (2012)
• Nicole King’s lab website

ABSTRACT
As the closest living relatives of animals, choanoflagellates offer insights into the ancestry of animal cell physiology. Here, we report the isolation and characterization of a colonial choanoflagellate from Mono Lake, California. The choanoflagellate forms large spherical colonies that are an order of magnitude larger than those formed by the closely related choanoflagellate Salpingoeca rosetta. In cultures maintained in the laboratory, the lumen of the spherical colony is filled with a branched network of extracellular matrix and colonized by bacteria, including diverse Gammaproteobacteria and Alphaproteobacteria. We propose to erect Barroeca monosierra gen. nov., sp. nov. Hake, Burkhardt, Richter, and King to accommodate this extremophile choanoflagellate. The physical association between bacteria and B. monosierra in culture presents a new experimental model for investigating interactions among bacteria and eukaryotes. Future work will investigate the nature of these interactions in wild populations and the mechanisms underpinning the colonization of B. monosierra spheres by bacteria.

IMPORTANCE
The diversity of organisms that live in the extreme environment of Mono Lake (California, USA) is limited. We sought to investigate whether the closest living relatives of animals, the choanoflagellates, exist in Mono Lake, a hypersaline, alkaline, arsenic-rich environment. We repeatedly isolated members of a new species of choanoflagellate, which we have named Barroeca monosierra. Characterization of B. monosierra revealed that it forms large spherical colonies containing diverse co-isolated bacteria, providing an opportunity to investigate mechanisms underlying physical associations between eukaryotes and bacteria.

OBSERVATION

A newly identified choanoflagellate species forms large spherical colonies

Choanoflagellates are the closest living relatives of animals and, as such, provide insights into the origin of key features of animal biology (1, 2). Over five sampling trips to Mono Lake, California (Fig. 1A; Table S1), we collected single-celled choanoflagellates and large spherical choanoflagellate colonies, many of which were seemingly hollow (Fig. 1B). In colonies and single cells, each cell bore the diagnostic collar complex observed in other choanoflagellates: an apical flagellum surrounded by a collar of microvilli (1, 2). In the spherical colonies, each cell was oriented with the basal pole of the cell body facing inwards and the apical flagellum facing out (Fig. 1B). We know of no prior reports of choanoflagellates having been isolated and cultured from any hypersaline alkaline lake, including Mono Lake.

Fig 1

Fig 1 A colonial choanoflagellate isolated from Mono Lake. (A) Choanoflagellates were collected from three sampling sites (asterisks) near the shore of Mono Lake, California (modified from a map in the public domain, formatted as USGS Imagery Only; https://www.usgs.gov/volcanoes/long-valley-caldera) (B) B. monosierra forms large colonies (differential interference contrast image). Scale bar = 50 µm. (C) B. monosierra (shown in bold) is a craspedid choanoflagellate closely related to S. rosetta and Microstomoeca roanoka. Phylogeny based on sequences of three genes: 18S rRNA, EFL, and HSP90. Metazoa (seven species) were collapsed to save space. Bayesian posterior probabilities are indicated above each internal branch, and maximum likelihood bootstrap values are below. (A “—” value indicates a bifurcation lacking support or not present in one of the two reconstructions.) Also see Fig. S1C for further phylogenetic analyses. (D and E) Two colonies from the ML2.1G culture (Fig. S1, Box2) reveal the extremes of the B. monosierra colony size range (D, 58 µm diameter; E, 19 µm diameter; scale bar = 20 µm). In B. monosierra colonies, each cell is oriented with its apical flagellum (white; labeled with anti-tubulin antibody) and the apical collar of microvilli (red; stained with phalloidin) pointing out. Nuclei (cyan) were visualized with the DNA-stain Hoechst 33342. (F) Colonies of B. monosierra span from 10 µm in diameter, a size comparable to that of small S. rosetta colonies, to 120 µm, over an order of magnitude larger. The diameters of B. monosierra and S. rosetta colonies were plotted as a violin plot; the median is indicated as a thick black line. Diameters of the colonies in panels D and E are indicated as colored bars behind the violin plot (D, red bar; E, blue bar).

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Fig 2

Fig 2 Bacteria reside in the lumina of B. monosierra colonies. (A and A′) The center of a B. monosierra colony from culture ML2.1G (Fig. S1, Box 2), shown as a maximum intensity projection (A) and optical z-section (A′), contains DNA (revealed by Hoechst 33342 staining; cyan). Apical flagella were labeled with anti-tubulin antibody (white); microvilli were stained with phalloidin (red). Hoechst 33342 staining (cyan) revealed the spherical choanoflagellate nuclei along the colony perimeter and an amorphous cloud of DNA sitting within the central cavity formed by the monolayer of choanoflagellate cells. (B, B’’ and B′) A thin section through a B. monosierra colony, imaged by transmission electron microscopy (TEM), revealed the presence of small cells in the central cavity. (B′) Inset (box from panel B) reveals that the interior cells are each surrounded by a cell wall. (C, C’’, C’’’, and C″′′) The small cells inside B. monosierra colonies (grown from cultures ML2.1E/ML2.1EC) are bacteria, as revealed by hybridization with a broad-spectrum 16S rRNA probe (C, green) and a probe targeting Gammaproteobacteria (C′, red). Choanoflagellate nuclei and bacterial nucleoids were revealed by staining with Hoechst (C″, cyan). (C″′) Merge of panels C, C′, and C″. Scale bar for all = 5 µm. (D, D’ and D″) 3D reconstruction of a 70-cell B. monosierra colony from transmission electron micrographs of serial ultrathin sections revealed that the bacteria are closely associated with and wrapped around the extracellular matrix (ECM) inside the colony. (D) Whole colony view. (D′) Cut-away view of colony center. False colors indicate cell bodies (cyan), microvilli (orange), flagella (green), bacteria (red), ECM (white), intercellular bridges (yellow; see also Fig. S5), and filopodia (purple). (D″) Reducing the opacity of the choanoflagellate cell renderings revealed the presence of bacteria positioned between the lateral surfaces of choanoflagellate cells (brackets; see also Fig. S7). (E) Representative B. monosierra colony from an environmental sample shown as an average intensity projection (planes 17–27 from 1-µm optical sections). Choanoflagellate nuclei and bacterial nucleoids (examples indicated by arrowheads) were revealed by staining with Hoechst (cyan). To allow visualization of the much smaller bacterial nucleoids, the imaging of the choanoflagellate nuclei was saturated. Concanavalin A staining (magenta) revealed the branched extracellular matrix. (F and G) Optical sections 19 and 24, respectively, of the B. monosierra colony shown in panel E. (F′ and G′) Higher magnification Hoechst-stained DNA from the boxed regions in F and G, highlighting the resident bacteria (examples indicated by arrowheads). Scale bars in panels E–G = 10 μm.

This discovery shows a plausible route to multicellularity from a related single-celled eukaryote organism and offers an explanation for the early stages of embryo development where a single-cell zygote gives rise early on to a hollow gastrula. This could have formed in an ancestral multicellular metazoan as somewhere for a symbiotic colony of bacteria to reside and provide nutrients in return for protection. It also offers a plausible explanation for our commensal, symbiotic microbiome in our gut which has its embryonic origins in the hollow gastrula.

Creationists might also like to ignore the fact that the research team believe they are explaining a fundamental step in the evolution of multicellularity 650 million years ago, and have found no need to abandon science and the scientific method and turn to creationism with its magic and unproven entities for a more rational explanation of the facts.

And of course, as with 99.9975% of all history, this stage in the evolution of multicellular life happened in that long, pre-'Creation Week', period of Earth's history.

Malevolent Design - How The Malevolent Designer Perfected The Mosquito As Its Favourite Parasite Delivery System

Thermal image of human bodies

Photo Credit: Ildar Abulkhanov via iStock

Mosquitoes sense infrared from body heat to help track humans down | The Current

To an intelligent [sic] design creationists it must seem that the mosquito is the divine malevolence's delivery system of choice for getting its parasites into as many people as possible to maximise the suffering in the world.

There are others of course, such as the tsetse fly that delivers the parasite that causes sleeping sickness to humans and their cattle, which is probably the major reason Africans never developed agriculture, and ticks do their bit in spreading diseases too, but none are as effective as the mosquito which is responsible for transmitting parasites that cause the deaths of half a million or more people annually.

The World Health Organization has estimated that malaria alone causes 400,000 deaths a year, mostly children, then there is dengue, yellow fever, zika and several other diseases transmitted by the female mosquito when she takes a blood meal. To keep the blood flowing she first injects saliva which contains an anticoagulant. It also contains viruses and microorganisms such as Plasmodium falciparum.

What viruses and parasites are female mosquitoes the vectors for and how do these affect the human population? Female mosquitoes are notorious vectors for several viruses and parasites that significantly impact human health. Here’s an overview of the main pathogens they transmit and their effects on the human population:

1. Malaria
   • Pathogen: Plasmodium parasites (primarily Plasmodium falciparum, P. vivax, P. ovale, and P. malariae)
   • Vector: Anopheles mosquitoes
   • Effect on Humans: Malaria is one of the deadliest diseases transmitted by mosquitoes, causing symptoms like fever, chills, and flu-like illness. Severe cases can lead to anemia, cerebral malaria, and death. Malaria remains a major public health problem, particularly in sub-Saharan Africa, causing over 600,000 deaths annually, most of which are children under five years old.
   
   
2. Dengue Fever
   • Pathogen: Dengue virus (DENV), which has four serotypes (DENV-1 to DENV-4)
   • Vector: Aedes aegypti and Aedes albopictus mosquitoes
   • Effect on Humans: Dengue fever causes high fever, severe headache, pain behind the eyes, joint and muscle pain, and rash. Severe forms, such as dengue hemorrhagic fever and dengue shock syndrome, can be fatal. Dengue is a major cause of illness in tropical and subtropical regions, with an estimated 100 million cases occurring annually.
   
   
3. Zika Virus
   • Pathogen: Zika virus (ZIKV)
   • Vector: Aedes aegypti and Aedes albopictus mosquitoes
   • Effect on Humans: Zika virus usually causes mild symptoms like fever, rash, and joint pain. However, it can cause severe birth defects, particularly microcephaly, when a pregnant woman is infected. Zika outbreaks have occurred in Africa, Southeast Asia, and the Pacific Islands, with the most notable outbreak occurring in Brazil in 2015-2016.
   
   
4. Chikungunya
   • Pathogen: Chikungunya virus (CHIKV)
   • Vector: Aedes aegypti and Aedes albopictus mosquitoes
   • Effect on Humans: Chikungunya causes fever and severe joint pain, often leading to chronic pain that can last for months or even years. The disease is rarely fatal, but it significantly impacts quality of life. It has caused numerous outbreaks in Africa, Asia, and the Americas.
   
   
5. Yellow Fever
   • Pathogen: Yellow fever virus (YFV)
   • Vector: Aedes aegypti mosquitoes
   • Effect on Humans: Yellow fever can range from mild symptoms like fever and muscle pain to severe liver disease with bleeding and jaundice, often leading to death. The disease is endemic in tropical areas of Africa and Central and South America, and despite the availability of a vaccine, it still causes significant mortality in unvaccinated populations.
   
   
6. West Nile Virus
   • Pathogen: West Nile virus (WNV)
   • Vector: Culex species mosquitoes
   • Effect on Humans: West Nile virus can cause a range of symptoms, from mild fever to severe neurological diseases such as encephalitis and meningitis. While most infections are asymptomatic, severe cases can lead to long-term neurological damage or death. The virus is prevalent in Africa, Europe, the Middle East, and the Americas.
   
   
7. Lymphatic Filariasis (Elephantiasis)
   • Pathogen: Wuchereria bancrofti, Brugia malayi, and Brugia timori (parasitic worms)
   • Vector: Culex, Anopheles, and Aedes mosquitoes
   • Effect on Humans: Lymphatic filariasis is a debilitating disease that causes lymphedema (swelling due to lymphatic system blockage), leading to severe disability and social stigma. The condition, known as elephantiasis, causes the enlargement and hardening of limbs and genitals. It affects millions of people, primarily in tropical and subtropical regions.
   
   
8. Rift Valley Fever
   • Pathogen: Rift Valley fever virus (RVFV)
   • Vector: Various mosquito species, including Aedes and Culex
   • Effect on Humans: Rift Valley fever primarily affects animals, but humans can also contract the virus, leading to symptoms like fever, muscle pain, and in severe cases, hemorrhagic fever, encephalitis, or blindness. Outbreaks are often associated with heavy rainfall and flooding, particularly in sub-Saharan Africa.
   
   
9. Japanese Encephalitis
   • Pathogen: Japanese encephalitis virus (JEV)
   • Vector: Culex species mosquitoes
   • Effect on Humans: Japanese encephalitis causes inflammation of the brain, leading to symptoms like fever, headache, vomiting, and neurological symptoms, including seizures and paralysis. It can be fatal or cause permanent neurological damage. The disease is endemic in parts of Asia and the Western Pacific.

Public Health Impact
The diseases transmitted by female mosquitoes have a profound impact on public health worldwide, particularly in tropical and subtropical regions. The economic burden includes the cost of medical treatment, lost productivity, and vector control programs. These diseases also contribute to poverty and hinder economic development in affected regions.

Efforts to combat mosquito-borne diseases include widespread vaccination campaigns (where vaccines are available), distribution of insecticide-treated bed nets, indoor residual spraying, and public health campaigns to reduce mosquito breeding sites. However, the control and eradication of these diseases remain challenging due to factors like insecticide resistance, climate change, and the rapid urbanization of tropical areas.

It is this act of injecting saliva which make the female mosquito such a dangerous insect, together with the fact that it seems to have salivary glands designed to contain the viruses and parasites.

But of course, to be really effective, the female mosquito must first find a victim. How she does this is the subject of a paper by A team led by researchers at the University of California Santa Barbara recently published, open access, in Nature and explained in a UC Sata Barbara News release:

Mosquitoes sense infrared from body heat to help track humans down

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While a mosquito bite is often no more than a temporary bother, in many parts of the world it can be scary. One mosquito species, Aedes aegypti, spreads the viruses that cause over 100,000,000 cases of dengue, yellow fever, Zika and other diseases every year. Another, Anopheles gambiae, spreads the parasite that causes malaria. The World Health Organization estimates that malaria alone causes more than 400,000 deaths every year. Indeed, their capacity to transmit disease has earned mosquitoes the title of deadliest animal.

Male mosquitoes are harmless, but females need blood for egg development. It’s no surprise that there’s over 100 years of rigorous research on how they find their hosts. Over that time, scientists have discovered there is no one single cue that these insects rely on. Instead, they integrate information from many different senses across various distances.

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A team led by researchers at UC Santa Barbara has added another sense to the mosquito’s documented repertoire: infrared detection. Infrared radiation from a source roughly the temperature of human skin doubled the insects’ overall host-seeking behavior when combined with \(\small \ce{CO2}\) and human odor. The mosquitoes overwhelmingly navigated toward this infrared source while host seeking. The researchers also discovered where this infrared detector is located and how it works on a morphological and biochemical level. The results are detailed in the journal Nature.

The mosquito we study, Aedes aegypti, is exceptionally skilled at finding human hosts. This work sheds new light on how they achieve this.

Dr. Nicolas DeBeaubien, co-lead author
Department of Molecular, Cellular, and Developmental Biology
University of California, Santa Barbara, CA, USA.

Guided by thermal infrared

It is well established that mosquitoes like Aedes aegypti use multiple cues to home in on hosts from a distance.

These include \(\small \ce{CO2}\) from our exhaled breath, odors, vision, [convection] heat from our skin, and humidity from our bodies. However, each of these cues have limitations.

Dr. Avinash Chandel, co-lead author
Department of Molecular, Cellular, and Developmental Biology
University of California, Santa Barbara, CA, USA.

The insects have poor vision, and a strong wind or rapid movement of the human host can throw off their tracking of the chemical senses. So the authors wondered if mosquitoes could detect a more reliable directional cue, like infrared radiation.

Within about 10 cm, these insects can detect the heat rising from our skin. And they can directly sense the temperature of our skin once they land. These two senses correspond to two of the three kinds of heat transfer: convection, heat carried away by a medium like air, and conduction, heat via direct touch. But energy from heat can also travel longer distances when converted into electromagnetic waves, generally in the infrared (IR) range of the spectrum. The IR can then heat whatever it hits. Animals like pit vipers can sense thermal IR from warm prey, and the team wondered whether mosquitoes, like Aedes aegypti, could as well.

The researchers put female mosquitoes in a cage and measured their host-seeking activity in two zones. Each zone was exposed to human odors and \(\small \ce{CO2}\) at the same concentration that we exhale. However, only one zone was also exposed to IR from a source at skin temperature. A barrier separated the source from the chamber prevented heat exchange through conduction and convection. They then counted how many mosquitoes began probing as if they were searching for a vein.

Adding thermal IR from a 34º Celcius source (about skin temperature) doubled the insects’ host-seeking activity. This makes infrared radiation a newly documented sense that mosquitoes use to locate us. And the team discovered it remains effective up to about 70 cm (2.5 feet).

What struck me most about this work was just how strong of a cue IR ended up being. Once we got all the parameters just right, the results were undeniably clear.

Dr. Nicolas DeBeaubien.

Previous studies didn’t observe any effect of thermal infrared on mosquito behavior, but senior author Craig Montell suspects this comes down to methodology. An assiduous scientist might try to isolate the effect of thermal IR on insects by only presenting an infrared signal without any other cues. “But any single cue alone doesn’t stimulate host-seeking activity. It’s only in the context of other cues, such as elevated \(\small \ce{CO2}\) and human odor that IR makes a difference,” said Montell, the Duggan and Distinguished Professor of Molecular, Cellular, and Developmental Biology. In fact, his team found the same thing in tests with only IR: infrared alone has no impact.

A trick for sensing infrared

It isn’t possible for mosquitoes to detect thermal infrared radiation the same way they would detect visible light. The energy of IR is far too low to activate the rhodopsin proteins that detect visible light in animal eyes. Electromagnetic radiation with a wavelength longer than about 700 nanometers won’t activate rhodopsin, and IR generated from body heat is around 9,300 nm. In fact, no known protein is activated by radiation with such long wavelengths, Montell said. But there is another way to detect IR.

Consider heat emitted by the sun. The heat is converted into IR, which streams through empty space. When the IR reaches Earth, it hits atoms in the atmosphere, transferring energy and warming the planet. “You have heat converted into electromagnetic waves, which is being converted back into heat,” Montell said. He noted that the IR coming from the sun has a different wavelength from the IR generated by our body heat, since the wavelength depends on the temperature of the source.

The authors thought that perhaps our body heat, which generates IR, might then hit certain neurons in the mosquito, activating them by heating them up. That would enable the mosquitoes to detect the radiation indirectly.

Scientists have known that the tips of a mosquito’s antennae have heat-sensing neurons. And the team discovered that removing these tips eliminated the mosquitoes’ ability to detect IR.

Indeed, another lab found the temperature-sensitive protein, TRPA1, in the end of the antenna. And the UCSB team observed that animals without a functional trpA1 gene, which codes for the protein, couldn’t detect IR.

Pits at the end of the mosquito’s antennae shield the peg-like structures that detect thermal IR.

Photo Credit: deBeaubien and Chandel et al.

The tip of each antenna has peg-in-pit structures that are well adapted to sensing radiation. The pit shields the peg from conductive and convective heat, enabling the highly directional IR radiation to enter and warm up the structure. The mosquito then uses TRPA1 — essentially a temperature sensor — to detect infrared radiation.

Diving into the biochemistry

The activity of the heat-activated TRPA1 channel alone might not fully explain the range over which mosquitoes were able to detect IR. A sensor that exclusively relied on this protein may not be useful at the 70 cm range the team had observed. At this distance there likely isn’t sufficient IR collected by the peg-in-pit structure to heat it enough to activate TRPA1.

Fortunately, Montell’s group thought there might be more sensitive temperature receptors based on their previous work on fruit flies in 2011. They had found a few proteins in the rhodopsin family that were quite sensitive to small increases in temperature. Although rhodopsins were originally thought of exclusively as light detectors, Montell’s group found that certain rhodopsins can be triggered by a variety of stimuli. They discovered that proteins in this group are quite versatile, involved not just in vision, but also in taste and temperature sensing. Upon further investigation, the researchers discovered that two of the 10 rhodopsins found in mosquitoes are expressed in the same antennal neurons as TRPA1.

Knocking out TRPA1 eliminated the mosquito’s sensitivity to IR. But insects with faults in either of the rhodopsins, Op1 or Op2, were unaffected. Even knocking out both the rhodopsins together didn’t entirely eliminate the animal’s sensitivity to IR, although it significantly weakened the sense.

Their results indicated that more intense thermal IR — like what a mosquito would experience at closer range (for example, around 1 foot) — directly activates TRPA1. Meanwhile, Op1 and Op2 can get activated at lower levels of thermal IR, and then indirectly trigger TRPA1. Since our skin temperature is constant, extending the sensitivity of TRPA1 effectively extends the range of the mosquito’s IR sensor to around 2.5 ft.

A tactical advantage

Half the world’s population is at risk for mosquito-borne diseases, and about a billion people get infected every year, Chandel said. What’s more, climate change and worldwide travel have extended the ranges of Aedes aegypti beyond tropical and subtropical countries. These mosquitoes are now present in places in the US where they were never found just a few years ago, including California.

The team’s discovery could provide a way to improve methods for suppressing mosquito populations. For instance, incorporating thermal IR from sources around skin temperature could make mosquito traps more effective. The findings also help explain why loose-fitting clothing is particularly good at preventing bites. Not only does it block the mosquito from reaching our skin, it also allows the IR to dissipate between our skin and the clothing so the mosquitoes cannot detect it.

Loose fitting clothing lets through less IR.

Photo Credit: deBeaubien and Chandel et al.

Despite their diminutive size, mosquitoes are responsible for more human deaths than any other animal. Our research enhances the understanding of how mosquitoes target humans and offers new possibilities for controlling the transmission of mosquito-borne diseases.

Dr. Nicolas DeBeaubien

In addition to the Montell team, Vincent Salgado, formerly at BASF, and his student, Andreas Krumhotz, contributed to this study.

The technical details will tell creationists just how clever their favourite malevolence has been in its mosquito design:

Abstract
Mosquito-borne diseases affect hundreds of millions of people annually and disproportionately impact the developing world^1,2. One mosquito species, Aedes aegypti, is a primary vector of viruses that cause dengue, yellow fever and Zika. The attraction of Ae. aegypti female mosquitos to humans requires integrating multiple cues, including \(\small \ce{CO2}\) from breath, organic odours from skin and visual cues, all sensed at mid and long ranges, and other cues sensed at very close range^3,4,5,6. Here we identify a cue that Ae. aegypti use as part of their sensory arsenal to find humans. We demonstrate that Ae. aegypti sense the infrared (IR) radiation emanating from their targets and use this information in combination with other cues for highly effective mid-range navigation. Detection of thermal IR requires the heat-activated channel TRPA1, which is expressed in neurons at the tip of the antenna. Two opsins are co-expressed with TRPA1 in these neurons and promote the detection of lower IR intensities. We propose that radiant energy causes local heating at the end of the antenna, thereby activating temperature-sensitive receptors in thermosensory neurons. The realization that thermal IR radiation is an outstanding mid-range directional cue expands our understanding as to how mosquitoes are exquisitely effective in locating hosts.

Main
Aedes aegypti is an invasive mosquito species that transmits flaviviruses, impacting a growing proportion of the world’s population^1,2. As female mosquitoes blood feed multiple times, they often shuttle viruses causing diseases ranging from dengue to yellow fever, Zika and chikungunya2. Ae. aegypti integrate multiple sensory cues to locate and navigate towards humans^3,4,5,6 (Fig. 1a). Integration is essential as any single stimulus is inadequate to differentiate humans from other targets. Detection of exhaled \(\small \ce{CO2}\) elevates their locomotor activity and increases their responsiveness to other host-derived stimuli, such as visual cues^3,4,5,6. However, Ae. aegypti has poor visual acuity, limiting its usefulness in discriminating between people and other hosts⁷. Organic olfactory cues are particularly important for finding humans. However, the efficacy of \(\small \ce{CO2}\) and olfactory cues in providing directional information is limited by air-current disturbances that exceed the mosquito’s flight speed, or if the host is moving quickly⁸. When mosquitoes are very close to the skin surface, they detect moisture and convective body heat^4,9.

Fig. 1: Set-up for testing IR radiation as a potential host-associated cue.

a, Known host-associated sensory cues. b, Modes of thermal energy transfer: convection, conduction and IR radiation. The peak emission wavelength (λ^M) of emitting bodies at 34 °C is around 9.4 µm. c, The host-associated cues presented during the assay: human odour, 5% (v/v) \(\small \ce{CO2}\) and heat in the form of IR radiation. Assay cages were 4 cm from the arena wall that housed the Peltier device to mitigate the effect of convective cues. Human odour was applied uniformly on the outside of the mesh of the assay cage from a used nitrile glove. \(\small \ce{CO2}\) was delivered through perforated tubing, which formed a perimeter around both the control and IR zones. d, The Peltier device housing. An IR-transparent polyethylene (PE) film blocked convective cues from reaching the mosquitoes. e, Schematic of the behavioural assay. Mosquitoes were presented with IR and their host-seeking behaviour was video recorded for 5 min. f, Representative video frame taken from an experiment in which females were exposed to human odour and 5% \(\small \ce{CO2}\). One zone was exposed to 34 °C radiant heat from a Peltier device. The Peltier device behind the other zone was off, and equilibrated to the ambient temperature (temp.) (29.5 °C). The position of each host-seeking mosquito was recorded during the experimental window. In all of the experiments in which \(\small \ce{CO2}\) was provided, it was applied using the indicated time series (in seconds) unless otherwise stated. g, The PI, calculated from the indicated formula, using the total number of host-seeking observations in each zone during the 5 min experiment. PI < 0 indicates preference for zone 1; PI > 0 indicates preference for zone 2.

Thermal energy is transferred through conduction, convection and radiation (Fig. 1b). Mosquito attraction to heat depends at least in part on the antenna^10,11. The terminal antennal segment contains neurons that respond to cooling and warming^12,13,14,15. Conduction requires contact and is not useful during host-seeking flight. Convective currents move upwards and are sensed only at distances of less than 10 cm (ref. ¹⁶). Detecting convective heat from hosts at short range is promoted by a general attraction to warmth, and by avoiding both cool and very hot temperatures¹⁷. Elimination of either of two ionotropic receptors from cooling-responsive neurons impairs attraction to convection heat^14,18. Moreover, disruption of the Aedes TRPA1 channel impairs avoidance of very hot temperatures at close range (50−60 °C), but does not impair the responses to surfaces ≤45 °C (ref. ¹⁷). The neurons that depend on TRPA1 for avoiding noxious heat remain to be identified. In Anopheles gambiae, trpA1 is expressed at the antennal tip15, although its thermosensory role is unclear.

Conductive heat requires contact, and convective heat is sensed at close range16. Thus, if mosquitoes sense thermal IR radiation, then surface body temperature could be detected at greater distances, as radiant heat is not limited by the physical constraints of convection and conduction. Thermal IR emitted by humans (~34 °C skin surface) has a peak emission wavelength of around 9.4 μm, with 90% of its energy between 3–30 μm (ref. ¹⁹). This electromagnetic radiation is much lower energy than the ~300–700 nm wavelengths that activate rhodopsins²⁰. Thus, if mosquitoes detect thermal IR, this sensation should not rely on phototransduction.

Few animals are thought to sense IR for navigation or sensing prey. These include rattlesnakes^21,22, certain beetles^23,24, western conifer seed bugs²⁵, kissing bugs and ticks^26,27. By contrast, it has been reported that mosquitoes, including Ae. aegypti, are not attracted to IR^9,28,29 However, in these studies, thermal IR was presented alone rather than in the presence of other host-associated stimuli^9,28,29. Given the importance of multisensory integration in host seeking^3,4,5,6, we wondered whether mosquitoes might exhibit attraction to thermal IR, but only in combination with other host cues.

[…]

Discussion
The finding that thermal IR is an important cue that Ae. aegypti females use to find their targets counters reports that Ae. aegypti do not respond behaviourally to thermal IR^9,28,29. However, previous research examined IR in isolation. Ae. aegypti require multisensory integration to home in on people, and individual human-associated cues, such as IR, \(\small \ce{CO2}\) plumes and organic odours, have little efficacy in stimulating host-seeking behaviour on their own^3,4,5,6. Our finding that IR is used in combination with other cues adds critical breadth to the Aedes toolkit—allowing them to home in on humans from mid-range distance in varied and dynamic environments.

The thermal IR that emanates from surface body temperature is far lower in energy than the longest wavelengths that activate visual pigments²⁰. Rather than detecting photons directly, a more plausible mechanism for thermal IR detection is that the radiant energy warms dendrites in coeloconic sensilla near to the tip of the antenna, which in turn activates thermosensitive receptors. In support of this model, removal of the distal portion of the antenna, which contains heat-sensitive neurons^12,13,15, eliminates IR attraction. While past research reports that the coeloconic sensilla at the distal end of the antenna sense convective heat¹³, the design of the thermosensitive peg-in-pit coeloconic sensilla at the antennal tip is more consistent with a sensor of radiant than of convective heat. Located in a pit, the neurons would be largely protected from convective currents, and would receive radiant heat preferentially from the direction of the pit aperture. Directionality is important for a radiant heat sensor, but would reduce the sensitivity of a convective heat sensor. Nevertheless, at very close range, the neurons in peg-in-pit sensilla would also be activated by convection heat.

We propose that IR impinging on the peg-in-pit sensilla is partially absorbed by the cuticle, and then energy is transferred to the endolymph through conduction. Some IR might also penetrate the cuticle and directly warm the endolymph. We found that the heat-activated TRPA1 channel is expressed in neurons at the antennal tip and is required for responding to IR. By contrast, trpA1 mutants display normal attraction to conductive/convective heat in the temperature range of human skin¹⁷. In the presence of conductive/convective heat, the role for TRPA1 is to help to avoid ≥50 °C conditions (ref. ¹⁷), even though TRPA1 is activated with a threshold of only around 32 °C (ref. ⁴¹). The anatomical location for this close-range TRPA1 function appears to be distinct from IR sensation. Our data support the model that TRPA1 senses IR at mid-range distances (~0.7 m) through the ‘warming neurons’ in the peg-in-pit sensilla.

Two opsins (op1, op2) and trpA1 are co-expressed at the end of the antenna, and mutations eliminating these opsins reduce IR sensation, but only at lower intensities of radiant heat. We propose that contributions of both opsins and TRPA1 to detecting radiant heat endows mosquitoes with a greater dynamic range for sensing radiant heating. We suggest that, at higher IR intensities, the radiant heat is sufficient to directly activate TRPA1, while, at lower levels of thermal IR, activation of the opsins initiates a cascade that amplifies the signal and indirectly activates TRPA1.

In conclusion, thermal IR represents an important mid-range cue that is used by Ae. aegypti to couple longer- and shorter-range cues. As An. stephensi are also attracted to thermal IR, we speculate that detection of the IR may be widely used among blood-feeding mosquitoes to home in on warm-blooded hosts. Finally, the finding that thermal IR is an effective host-seeking cue raises the possibility of developing strategies to interfere with this attraction, and the opportunity to devise more effective mosquito baits (Supplementary Discussion).

Chandel, A., DeBeaubien, N.A., Ganguly, A. et al.
Thermal infrared directs host-seeking behaviour in Aedes aegypti mosquitoes. Nature (2024). https://doi.org/10.1038/s41586-024-07848-5

Copyright: © 2024 The authors.
Published by Springer Nature Ltd. Open access.
Reprinted under a Creative Commons Attribution 4.0 International license (CC BY 4.0)

Clearly, if we assume for the sake of argument that intelligent [sic] design creationism has any merit, a great deal of design perfection has gone into designing the ways in which mosquitoes find their victims and deliver their cargo of infectious parasites. Just in case any creationists feel tempted to suggest that delivering parasites to warm-blooded animals like humans was not the design purpose of mosquitoes, it should be pointed out that their putative designer is allegedly both omniscient and omnipotent so anything it designs is designed in full knowledge of what it will do and, if in the unlikely event of undesired outcome, scrapping the design and starting again should be well within the designer's capability, so we have to assume any outcome was intentional and the purpose of the design.

And of course, we can dismiss the traditional creationist excuse of 'genetic entropy' causing 'devolution' [sic] as Michael J Behe's excuse for parasites, since the clever design for finding a blood meal is distinctly advantageous for the mosquito and can't possibly be described as 'devolution'.

If we don't assume intelligent design, however, we are left with a mindless evolutionary process with no plan and no intent, malevolent or otherwise. We are left with a full and complete explanation of how and why mosquitoes have these abilities and why they infect us with parasites, so increasing the suffering in the world - there is no benevolent god organising it.

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This book presents the reader with multiple examples of why, even if we accept Creationism's putative intelligent designer, any such entity can only be regarded as malevolent, designing ever-more ingenious ways to make life difficult for living things, including humans, for no other reason than the sheer pleasure of doing so. This putative creator has also given other creatures much better things like immune systems, eyesight and ability to regenerate limbs that it could have given to all its creation, including humans, but chose not to. This book will leave creationists with the dilemma of explaining why evolution by natural selection is the only plausible explanation for so many nasty little parasites that doesn't leave their creator looking like an ingenious, sadistic, misanthropic, malevolence finding ever more ways to increase pain and suffering in the world, and not the omnibenevolent, maximally good god that Creationists of all Abrahamic religions believe created everything. As with a previous book by this author, "The Unintelligent Designer: Refuting the Intelligent Design Hoax", this book comprehensively refutes any notion of intelligent design by anything resembling a loving, intelligent and maximally good god. Such evil could not exist in a universe created by such a god. Evil exists, therefore a maximally good, all-knowing, all-loving god does not.

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Creationism Refuted - How We Inherrited Part Of Our Anti-Viral Immune Response From A Microbial Ancestor

Credit: Pedro Leão.

A comparison of immune proteins called viperins from Asgard archaea (left) and from a group of more complex life that includes humans, called eukaryotes (right). The three-dimensional shapes (a.k.a. structures) are strikingly similar, suggesting they also function similarly.

Credit: Pedro Leão.

Next Time You Beat a Virus, Thank Your Microbial Ancestors | College of Natural Sciences

Multicellular organisms are collections of specialised eukaryote cells, which are themselves collections of prokaryote cells that have been around for several billion years before getting together to form more complex cells.

And those prokaryote cells - bacteria and archaea - had had to cope with viruses which arose as soon as there were replicating assemblages of DNA for them to parasitize and co-opt the replication mechanism to make more copies of themselves.

The result was one of the first evolutionary arms races as the prokaryotes evolved ways to prevent themselves being parasitised and viruses evolved ways to overcome the microbes defences.

And, or course, the later eukaryote, complex cells that were to form the multicellular organisms inherited these antiviral defences and carried on the arms race with viruses, so it makes sense to find some of the remnants of these microbial defences, probably modified, inside our own cells, and forming a first line of defences.

This is a simple prediction of the Theory of Evolution and the resulting descent with modification from a common ancestor from billions of years ago.

What information do you have on the anti-viral proteins, Asgard Viperin and Eukaryote Viperin? Asgard Viperin and Eukaryote Viperin are both antiviral proteins that play crucial roles in the innate immune response, particularly in targeting and neutralizing viral infections. They belong to a broader family of proteins called Viperin (virus inhibitory protein, endoplasmic reticulum-associated, interferon-inducible). Viperin is a well-known antiviral protein that is highly conserved across various species, including archaea, bacteria, and eukaryotes. Here's a breakdown of what is known about Asgard Viperin and Eukaryote Viperin:

1. Asgard Viperin
   • Origin: Asgard Viperin is derived from the Asgard archaea, a group of microorganisms that are thought to be closely related to the last common ancestor of archaea and eukaryotes. These archaea were discovered in deep-sea hydrothermal vent environments and are considered important in studying the evolution of complex life forms.
   • Function: Asgard Viperin has been identified as an antiviral protein that provides insights into the ancient mechanisms of immune defense. Its function is similar to that of Viperin in eukaryotes, where it inhibits viral replication by targeting viral components or the cellular machinery viruses depend on for replication.
   • Structure and Mechanism: Like other Viperins, Asgard Viperin is likely to have a radical SAM (S-adenosylmethionine) domain, which is critical for its antiviral activity. This domain allows the protein to produce a reactive radical species, which can interfere with viral processes, such as the synthesis of nucleotides that viruses require for replication.
   • Evolutionary Significance: The discovery of Asgard Viperin highlights the ancient origins of antiviral defense mechanisms. It suggests that the strategies used by modern eukaryotic cells to combat viruses may have deep evolutionary roots.
2. Eukaryote Viperin
   • Origin: Eukaryote Viperin is found in eukaryotic organisms, including humans. It is one of the interferon-stimulated genes (ISGs) that are upregulated in response to viral infection. This protein is highly conserved across various species, from simple eukaryotes like algae to complex organisms like mammals.
   • Function: In eukaryotes, Viperin is a key player in the innate immune response. It exerts its antiviral effects through multiple mechanisms, depending on the type of virus. For example:
     • Inhibition of Viral Replication: Viperin can interfere with the replication of viruses by altering lipid metabolism or disrupting the assembly of viral particles.
     • Interaction with Cellular Machinery: It can inhibit viral RNA polymerase, thereby preventing the replication of RNA viruses.
     • Modulation of Immune Response: Viperin can enhance the production of other antiviral molecules and modulate the signaling pathways involved in the immune response.
   • Mechanism of Action: The radical SAM domain is crucial for the antiviral activity of Viperin in eukaryotes. This domain facilitates the formation of a radical species that can interfere with the function of viral proteins or the host cell machinery that viruses exploit.
   • Clinical Relevance: Understanding the role of Viperin in the immune response has significant implications for developing antiviral therapies. Since Viperin is involved in the response to a wide range of viruses, enhancing its activity could be a potential strategy for treating viral infections.

Comparative Insights

• The study of Asgard and Eukaryote Viperin provides valuable insights into the evolution of antiviral defense mechanisms. The presence of similar antiviral proteins in both archaea and eukaryotes suggests that these defense strategies are ancient and have been conserved throughout evolution.
• While both Asgard and Eukaryote Viperin share functional similarities, their specific roles and mechanisms may differ due to the differences in their cellular environments and the types of viruses they encounter.

Research Significance

• The discovery and study of Asgard Viperin contribute to our understanding of the origin of eukaryotic cells and their immune systems. It also opens up new avenues for research into the evolution of antiviral defenses and the development of new antiviral strategies based on ancient mechanisms.

Understanding these proteins, particularly in the context of their evolutionary history and their function in modern organisms, is crucial for advancing our knowledge of immune responses and the development of antiviral therapies.

And this is precisely what researchers in the College of Natural Science at The University of Texas at Austin have found. They have shown that the proteins Asgard Viperin from the Asgard archaea and the Eukaryote viperin, possessed by eukaryotes including humans are structurally (and functionally) very similar.

Next Time You Beat a Virus, Thank Your Microbial Ancestors

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Two of our key defenses against viruses have persisted for billions of years, arising before complex life.

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When you get infected with a virus, some of the first weapons your body deploys to fight it were passed down to us from our microbial ancestors billions of years ago. According to new research from The University of Texas at Austin, two key elements of our innate immune system came from a group of microbes called Asgard archaea.

Specifically, viperins and argonautes, two proteins that are known to play important roles in the immune systems of all complex life — from insects to plants to humans — came from the Asgard archaea. Versions of these defense proteins are also present in bacteria, but the versions in complex life forms are most closely related to those in Asgard archaea, according to the new scientific study published in the journal Nature Communications.

This research bolsters the idea that all complex life, called eukaryotes, arose from a symbiotic relationship between bacteria and Asgard archaea.

It adds more support to the fact that the Asgards are our microbial ancestors. It says that not only did eukaryotes get all these rich structural proteins that we’ve seen before in Asgards, now it’s saying that even some of the defense systems in eukaryotes came from Asgards.

Associate Professor Brett J. Baker, senior author
Associate professor of integrative biology and marine science
Department of Integrative Biology
University of Texas at Austin, Austin, TX, USA.

The researchers identified for the first time a large arsenal of defense systems in archaea that were previously known only in bacteria.

When viperins detect foreign DNA, which might indicate a dangerous virus, they edit the DNA so that the cell can no longer make copies of the DNA, which stops the virus from spreading. When argonautes detect foreign DNA, they chop it up, also halting the virus. Additionally, in more complex organisms, argonautes can block the virus from making proteins in a process called RNA silencing.

Viral infections are one of the evolutionary pressures that we have had since life began, and it is critical to always have some sort of defense. When bacteria and archaea discovered tools that worked, they were passed down and are still part of our first line of defense.

Assistant Professor Pedro Leão, lead author
Department of Microbiology - RIBES
Radboud University, Nijmegen, The Netherlands.

The researchers compared proteins involved in immunity across the tree of life and found many closely related ones. Then they used an AI tool called ColabFold to predict whether ones that had similar amino acid sequences also had similar three-dimensional shapes (aka structures). (It’s the shape of a protein that determines how it functions.) This showed that variations of the viperin protein probably maintained the same structure and function across the tree of life. They then created a kind of family tree, or phylogeny, of these sister amino acid sequences and structures that showed evolutionary relationships.

A family tree of immune proteins called viperins from different organisms. Versions of viperin found in complex life forms, called eukaryotes (green), fit within the group of viperins from Asgard archaea (purple).

Credit: University of Texas at Austin.

Finally, the researchers took viperins from Asgard archaea genomes, cloned them into bacteria (so the bacteria would express the proteins), challenged the bacteria with viruses, and showed that Asgard viperins do in fact provide some protection to the modified bacteria. They survived better than bacteria without the immune proteins.

This research highlights the integral role cellular defenses must have played from the beginning of both prokaryotic and eukaryotic life. It also inspires questions about how our modern understanding of eukaryotic immunity can benefit from unraveling some of its most ancient origins.

Emily Aguilar-Pine, co-author Department of Integrative Biology
University of Texas at Austin, Austin, TX, USA.

It’s undeniable at this point that Asgard archaea contributed a lot to the complexity that we see in eukaryotes today, so why wouldn’t they also be involved in the origin of the immune system? We have strong evidence now that this is true.

Assistant Professor Pedro Leão

Other authors, all from UT, are Mary Little, Kathryn Appler, Daphne Sahaya, Kathryn Currie, Ilya Finkelstein and Valerie De Anda.

This work was supported by the Simons and Moore foundations (via the Moore-Simons Project on the Origin of the Eukaryotic Cell) and The Welch Foundation.

Abstract
Dozens of new antiviral systems have been recently characterized in bacteria. Some of these systems are present in eukaryotes and appear to have originated in prokaryotes, but little is known about these defense mechanisms in archaea. Here, we explore the diversity and distribution of defense systems in archaea and identify 2610 complete systems in Asgardarchaeota, a group of archaea related to eukaryotes. The Asgard defense systems comprise 89 unique systems, including argonaute, NLR, Mokosh, viperin, Lassamu, and CBASS. Asgard viperin and argonaute proteins have structural homology to eukaryotic proteins, and phylogenetic analyses suggest that eukaryotic viperin proteins were derived from Asgard viperins. We show that Asgard viperins display anti-phage activity when heterologously expressed in bacteria. Eukaryotic and bacterial argonaute proteins appear to have originated in Asgardarchaeota, and Asgard argonaute proteins have argonaute-PIWI domains, key components of eukaryotic RNA interference systems. Our results support that Asgardarchaeota played important roles in the origin of antiviral defense systems in eukaryotes.

Introduction
Organisms across the tree of life contain complex defense systems (DS) to battle viral infections^1,2,3. Over the past decade, dozens of new DS have been identified and characterized in bacteria, sparking a debate about a potential link between these systems and the origins of innate immune mechanisms in eukaryotes. More recently, protein components of bacterial NLR (Nucleotide-binding domain leucine-rich repeat), CBASS (Cyclic oligonucleotide-based antiphage signaling system), viperins (virus-inhibitory protein, endoplasmic reticulum-associated, interferon (IFN)-inducible), argonautes, and other DS have been shown to exhibit homology with proteins involved in the eukaryotic immune system⁴. Most of the research on prokaryotic defense systems has focused on bacteria, with archaea representing <3% of the genomes in these studies^5,6,7. Thus, very little is known about the diversity or evolution of these systems in archaea.

Recently, diverse novel genomes have been obtained belonging to the archaea most closely related to eukaryotes, commonly referred to as “Asgard” archaea, the phylum Asgardarchaeota⁸. In addition to being sister lineages to eukaryotes, these archaea also contain an array of genes that are hallmarks of complex cellular life involved in signal processing, transcription, and translocations, among other processes⁹. The Asgard archaea are descendants of the ancestral host that gave rise to eukaryotic life. One newly described order, the Hodarchaeales (within the Heimdallarchaeia class), shared a common ancestor with eukaryotes⁸. Here, we characterize defense systems in archaea and show that Asgard archaea have a broad array of these DS. We also show that Asgards contributed to the origins of innate immune mechanisms in eukaryotes.

Fig. 2: Evolutionary history and anti-phage activity of Asgard viperins.

A Phylogenetic analysis of viperins. Viperins phylogeny revealed ancestral links of eVip (eukaryotic viperin) with asVip (asgard viperin) (nodes marked in red), particularly those within the Heimdallarchaeia class (including Kariarchaeaceae (2), Heimdallarchaeaceae (3) and Hodarchaeales (5)). The size of the dots on the nodes is proportional to bootstrap values ranging between 60 and 100. B Structure-based homology of viperins. Consistent with the sequence homology-based phylogenetic tree, the eVip structure appears to have been inherited from asVip (red node). The darker green color represents reference sequences predicted experimentally. The size of the dots at the center of the nodes is proportional to bootstrap values ranging between 50 and 100. C Superposition of an eVip structure, predicted by X-ray diffraction (green), and the structural models of an asVip, archaeal viperin (arVip), and bacterial viperin (from left to right). The yellow color in the models emphasizes the high conservation of the viperin catalytic site across the tree of life. The information regarding bacteria, archaea, asgard archaea and eukaryotes in panels (A–C) are represented by the pink, blue, purple and green color respectively. D Anti-T7 phage activity of asVip in E. coli. Nine asVip (asVip 26,11,20,25,16,12,17,23,8) exhibited anti-viral activity as indicated by the p-values (*p < 0.05; **p < 0.01). E Anti-T7 phage activity of asVip after codon optimization for their expression in E. coli. One asVip from a Hodarchaeales organism provided protection against viral infection (asVip 19). The center line of each box plot denotes the median; the box contains the 25^th to 75^th percentiles. Black whiskers mark the 5th and 95^th percentiles. pVip34 is a prokaryotic viperin selected as a positive control from Bernheim et al.¹³. Each experimental condition includes, on average, 53 plaques pooled from three biological replicates. A two-tailed t-test was used to calculate statistical significance in figures (E, D).

Fig. 3: Evolutionary history of Asgard argonaute proteins.

A Phylogeny of long type argonaute proteins from archaea, bacteria, and eukaryotes with cyclases as outgroup (grey). B Structure-based homology of argonautes. C Structural alignment of asAgo5 and 4OLA (eAgo) MID and PIWI domains (left), and the graphic model of the corresponding alignments (right). Salmon regions on the alignment highlight strong conservation (low RMDS values). Red amino acids in the structural alignment, and their respective models represent the 4OLA conserved functional residues in MID and PIWI. The information regarding bacteria, archaea, asgard archaea and eukaryotes are represented by the pink, blue, purple and green color respectively. The size of the dots on the nodes is proportional to bootstrap values ranging between 70 and 100.

Leão, P., Little, M.E., Appler, K.E. et al.
Asgard archaea defense systems and their roles in the origin of eukaryotic immunity.
Nat Commun 15, 6386 (2024). https://doi.org/10.1038/s41467-024-50195-2

Copyright: © 2024 The authors.
Published by Springer Nature Ltd. Open access.
Reprinted under a Creative Commons Attribution 4.0 International license (CC BY 4.0)

A highly-conserved antiviral protein across all eukaryote cells speaks loudly of common ancestry. The fact that a very similar protein is found in an "Asgard" archaea is strongly supportive of the theory that the fist eukaryote cells were alliances of bacteria and archaea and that the "Asgard" archaea contributed antiviral protection on this early eukaryote, showing common ancestry extending back beyond the first eukaryotes.

Of course, the less intelligent creationists will now be chanting 'Common Ancestry', but the more intelligent cultists would realise that that would mean the first eukaryote cells arose after Adam and Eve, because these antiviral proteins wouldn't have been needed until after 'Sin' had allowed viruses to 'devolve' by 'genetic entropy' (© Michael J. Behe), unless they don't understand how having an arms race with oneself is not the sign of an intelligent designer.