Tag Archives: chickens

Gene editing to identify and change parts of chicken DNA and limit the spread of bird flu virus

This news comes from the University of Edinburgh (Scotland). From an October 10, 2023 news item on phys.org, Note: A link has been removed,

Scientists have used gene editing techniques to identify and change parts of chicken DNA that could limit the spread of the bird flu virus in the animals.

Researchers were able to restrict—but not completely block—the virus from infecting chickens by altering a small section of their DNA.

The birds showed no signs that the change in their DNA had any impact on their health or well-being.

The findings are an encouraging step forward, but experts highlight that further gene edits would be needed to produce a chicken population which cannot be infected by bird flu—one of the world’s most costly animal diseases.

An October 10, 2023 University of Edinburgh press release, which originated the news item, provides more detail about this research,

Gene editing

Scientists from University of Edinburgh, Imperial College London and the Pirbright Institute bred the chickens using gene editing techniques to alter the section of DNA responsible for producing the protein ANP32A. During an infection, flu viruses hijack this molecule to help replicate themselves.

When the ANP32A gene-edited chickens were exposed to a normal dose of the H9N2-UDL strain of avian influenza virus – commonly known as bird flu – 9 out of 10 birds remained uninfected and there was no spread to other chickens.

Partial protection

The research team then exposed the gene-edited birds to an artificially high dose of avian influenza virus to further test their resilience.

When exposed to the high dose, half of the group – 5 out of 10 birds – became infected. However, the gene edit did provide some protection, with the amount of virus in the infected gene-edited chickens much lower than the level typically seen during infection in non-gene-edited chickens.

The gene edit also helped to limit onward spread of the virus to just one of four non-gene-edited chickens placed in the same incubator. There was no transmission to gene-edited birds.

Viral evolution

Scientists found that in the ANP32A gene-edited birds, the virus had adapted to enlist the support of two related proteins – ANP32B and ANP32E – to replicate.

Following lab tests, scientists found that some of the mutations enabled the virus to utilise the human version of ANP32, but its replication remained low in cell cultures from the human airway.

Experts say that additional genetic changes would be needed for the virus to infect and spread effectively in humans.

However, the findings demonstrate that the single ANP32A gene edit is not robust enough for application in the production of chickens, according to the team.

Gene editing

Scientists from University of Edinburgh, Imperial College London and the Pirbright Institute bred the chickens using gene editing techniques to alter the section of DNA responsible for producing the protein ANP32A. During an infection, flu viruses hijack this molecule to help replicate themselves.

When the ANP32A gene-edited chickens were exposed to a normal dose of the H9N2-UDL strain of avian influenza virus – commonly known as bird flu – 9 out of 10 birds remained uninfected and there was no spread to other chickens.

Partial protection

The research team then exposed the gene-edited birds to an artificially high dose of avian influenza virus to further test their resilience.

When exposed to the high dose, half of the group – 5 out of 10 birds – became infected. However, the gene edit did provide some protection, with the amount of virus in the infected gene-edited chickens much lower than the level typically seen during infection in non-gene-edited chickens.

The gene edit also helped to limit onward spread of the virus to just one of four non-gene-edited chickens placed in the same incubator. There was no transmission to gene-edited birds.

Viral evolution

Scientists found that in the ANP32A gene-edited birds, the virus had adapted to enlist the support of two related proteins – ANP32B and ANP32E – to replicate.

Following lab tests, scientists found that some of the mutations enabled the virus to utilise the human version of ANP32, but its replication remained low in cell cultures from the human airway.

Experts say that additional genetic changes would be needed for the virus to infect and spread effectively in humans.

However, the findings demonstrate that the single ANP32A gene edit is not robust enough for application in the production of chickens, according to the team.

Further edits

To prevent the emergence of escape viruses – viruses that adapt to evade the gene edit and cause infection – the research team next targeted additional sections of DNA responsible for producing all three proteins – ANP32A, ANP32B and ANP32E – inside lab-grown chicken cells.

In cell cultures in the lab, growth of the virus was successfully blocked in cells with the three gene edits.

The next step will be to try to develop chickens with edits to all three genes. No birds have been produced yet.

The study highlights the importance of responsible gene editing and the need to be alert to the risks of driving viral evolution in unwanted directions if complete resistance is not achieved, experts say.

Bird flu is a major global threat, with a devastating impact in both farmed and wild bird populations. In the UK alone, the current outbreak of H5N1 bird flu has decimated seabird populations and cost the poultry industry more than £100 million in losses.

In rare instances, mutations in the bird flu virus allow it to infect people and cause serious illness. Efforts to control the spread of the disease are urgently needed.

“Bird flu is a great threat to bird populations. Vaccination against the virus poses a number of challenges, with significant practical and cost issues associated with vaccine deployment. Gene-editing offers a promising route towards permanent disease resistance, which could be passed down through generations, protecting poultry and reducing the risks to humans and wild birds. Our work shows that stopping the spread of avian influenza in chickens will need several simultaneous genetic changes.” Professor Mike McGrew, The study’s principal investigator, from the University of Edinburgh’s Roslin Institute

“This work is an exciting collaboration that fuses our expertise in virology with the world-leading genetic capability at the Roslin Institute. Although we haven’t yet got the perfect combination of gene edits to take this approach into the field, the results have told us a lot about how influenza virus functions inside the infected cell and how to slow its replication.” Professor Wendy Barclay, Imperial College London

The research was funded by UKRI-BBSRC, which also provides strategic funding to The Roslin Institute, and was supported by Edinburgh Innovations, the University’s commercialisation service.

Ryan O’Hare’s October 10, 2023 Imperial College London (ICL) press release offers a slightly different perspective on the same work, Note: A link has been removed,

Scientists have successfully used gene editing techniques to limit the spread of bird flu in chickens.

In a UK first, researchers have been able to restrict, but not completely block, the avian influenza virus from infecting the birds by precisely altering a small section of their DNA.

The modified birds showed no signs that the change had any impact on the animals’ health or well-being.

But the researchers say that while the findings are encouraging, further gene edits would be needed to produce chickens which cannot be infected by bird flu.

The study, carried out by researchers from the University of Edinburgh, Imperial College London and the Pirbright Institute, is published in the journal Nature Communications.

Professor Wendy Barclay, Head of the Department of Infectious Disease at Imperial College London, said: “This work is an exciting collaboration that fuses our expertise in virology with the world world-leading genetic capability at the Roslin Institute.

“Although we haven’t yet got the perfect combination of gene edits to take this approach into the field, the results have told us a lot about how influenza virus functions inside the infected cell and how to slow its replication.”

Global Threat

Bird flu is a major global threat, with a devastating impact in both farmed and wild bird populations. In the UK alone, the current outbreak of H5N1 bird flu has decimated seabird populations and cost the poultry industry more than £100 million in losses.

In the latest study, researchers aimed to test whether precise edits to the chicken’s genome could potentially generate birds which are resistant to the virus.

The team bred chickens with small edits to a gene called ANP32A. During an infection, influenza viruses hijack the ANP32A protein to help replicate themselves.

But when the gene-edited birds were exposed to a normal dose of virus (the H9N2 strain of avian influenza), 9 out of 10 birds remained uninfected and there was no spread to other chickens.

When the birds were exposed to an artificially high dose of virus, only half of them became infected. The single gene edit also provided some protection against transmission, with a much lower amount of virus in infected gene-edited birds compared to non-edited birds.

In addition, the edit also helped to limit onward spread of the virus to just one of four non-edited chickens placed in the same incubator. There was no transmission to gene-edited birds.

Triple edits

Analysis revealed that in the edited birds, the virus adapted to enlist the support of two related proteins to replicate – ANP32B and ANP32E.

Following lab tests, the researchers found some of the mutations may enable the virus to utilise the human version of ANP32, but replication remained low in cell cultures from the human airway. The researchers stress that additional genetic changes would be needed for the virus to have the potential to infect and spread effectively in humans.

According to the team, the findings demonstrate that a single gene edit is not robust enough to produce resistant chickens. To prevent the emergence of viruses able to adapt to the single edit, the team next used a triple edit to target additional proteins (ANP32A, ANP32B and ANP32E) in lab-grown chicken cells.

In cell cultures in the lab, growth of the virus was successfully blocked in cells with edits to all three genes. In future, researchers hope to develop chickens with this triple edit, but no birds have been produced at this stage.

According to the researchers, the study highlights the importance of responsible gene editing and the need to be alert to the risks of driving viral evolution in unwanted directions if complete resistance is not achieved, experts say.

Professor Mike McGrew, from the University of Edinburgh’s Roslin Institute and principal investigator of the study, said: “Bird flu is a great threat to bird populations. Vaccination against the virus poses a number of challenges, with significant practical and cost issues associated with vaccine deployment.

“Gene-editing offers a promising route towards permanent disease resistance, which could be passed down through generations, protecting poultry and reducing the risks to humans and wild birds. Our work shows that stopping the spread of avian influenza in chickens will need several simultaneous genetic changes.”

A non-gene-edited chicken (left) pictured next to an ANP32A gene-edited chicken (right). Image credit: Norrie Russell Courtesy: University of Edinburgh

There’s also an October 10, 2023 article by Jon Cohen for Science.org, which gives some idea of how much work it took to get to this point, Note: Links have been removed,

For 3 decades, Helen Sang has tinkered with the genomes of chickens to try to make the birds resistant to the flu viruses that periodically devastate flocks and raise fears of a human pandemic. Now, as an especially virulent strain of avian influenza sweeps through poultry and wild birds around the world, the geneticist at the University of Edinburgh’s Roslin Institute has her first solid success. Using the CRISPR gene editor and recent findings about what makes poultry vulnerable to flu, Sang and colleagues from three other institutions have created chickens that can resist real-life doses of avian flu viruses. “Sticking to it gets you somewhere in the end,” she says.

The result, published today [October 5, 2023] in Nature Communications, is “a long-awaited achievement,” says Jiří Hejnar, a virologist at the Czech Academy of Sciences’s Institute of Molecular Genetics whose group showed in 2020 that CRISPR-edited chickens could resist a cancer-causing virus. But farmers won’t be raising flu-proof chickens anytime soon. The edited birds still became infected when exposed to larger amounts of the flu virus. And the strategy raises a safety concern: chickens edited this way could, in theory, drive the evolution of flu variants better at infecting people. “What this showed is a proof of concept,” says Wendy Barclay, a virologist at Imperial College London who worked on the new study. “But we’re not there yet.”

Here’s a link to and a citation for the paper,

Creating resistance to avian influenza infection through genome editing of the ANP32 gene family by Alewo Idoko-Akoh, Daniel H. Goldhill, Carol M. Sheppard, Dagmara Bialy, Jessica L. Quantrill, Ksenia Sukhova, Jonathan C. Brown, Samuel Richardson, Ciara Campbell, Lorna Taylor, Adrian Sherman, Salik Nazki, Jason S. Long, Michael A. Skinner, Holly Shelton, Helen M. Sang, Wendy S. Barclay & Mike J. McGrew. Nature Communications volume 14, Article number: 6136 (2023) DOI: https://doi.org/10.1038/s41467-023-41476-3 Published: 10 October 2023

This paper is open access.

Animal technology: a touchscreen for your dog, sonar lunch orders for dolphins, and more

A rather unexpected (for ignorant folks like me) approach to animal technology has been taken by Ilyena Hirskyj-Douglas in her June 17, 2016 piece on phys.org,

Imagine leaving your dog at home while it turns on the smart TV and chooses a programme to watch. Meanwhile you visit a zoo where you play interactive touchscreen games with the apes and watch the dolphins using sonar to order their lunch. In the field behind you, a farmer is stroking his flock of chickens virtually, leaving the drones to collect sheep while the cows milk themselves. Welcome to the unusual world of animal technology.

Hirskyj-Douglas’s piece was originally published as a June 15, 2016 essay  about animal-computer interaction (ACI) and some of the latest work being done in the field on The Conversation website (Note: Links have been removed),

Animals have interacted with technology for a long time, from tracking devices for conservation research to zoos with early touchscreen computers. But more recently, the field of animal-computer interaction (ACI) has begun to explore in more detail exactly how animals use technology like this. The hope is that better understanding animals’ relationship with technology will means we can use it to monitor and improve their welfare.

My own research involves building intelligent tracking devices for dogs that let them interact with media on a screen so we can study how dogs use TV and what they like to watch (if anything). Perhaps unsurprisingly, I’ve found that dogs like to watch videos of other dogs. This has led me to track dogs dogs’ gaze across individual and multiple screens and attempts to work out how best to make media just for dogs.

Eventually I hope to make an interactive system that allows a dog to pick what they want to watch and that evolves by learning what media they like. This isn’t to create a toy for indulgent pet owners. Dogs are often left at home alone during the day or isolated in kennels. So interactive media technology could improve the animals’ welfare by providing a stimulus and a source of entertainment. …

This 2014 video (embedded in Hirskyj-Douglas’s essay) illustrates how touchscreens are used by great apes,

It’s all quite intriguing and I encourage you to read the essay in it entirety.

If you find the great apes project interesting, you can find  out more about it (I believe it’s in the Primate Research category) and others at the Atlanta Zoo’s research webpage.

Could nanoparticles in your mouthwash affect for your cells?

The first news item I’m going to highlight was posted on Nanowerk, March 8, 2012 and is focused on the use of silver nanoparticles in mouthwashes and dentures to prevent yeast infections,

Yeasts which cause hard-to-treat mouth infections are killed using silver nanoparticles in the laboratory, scientists have found. These yeast infections, caused by Candida albicans and Candida glabrata target the young, old and immuno-compromised. Professor Mariana Henriques, University of Minho [Portugal], and her colleagues hope to test silver nanoparticles in mouthwash and dentures as a potential preventative measure against these infections.

Professor Henriques and her team, who published their research in the Society for Applied Microbiology’s journal Letters in Applied Microbiology(“Silver nanoparticles: influence of stabilizing agent and diameter on antifungal activity against Candida albicans and Candida glabrata biofilms”), looked at the use of different sizes of silver nanoparticles to determine their anti-fungal properties …

The scientists used artificial biofilms in conditions which mimic those of saliva as closely as possible. They then added different sizes and concentrations of silver nanoparticles and found that different sizes of nanoparticles were equally effective at killing the yeasts. Due to the diversity of the sizes of nanoparticles demonstrating anti-fungal properties the researchers hope this will enable the nanoparticles to be used in many different applications.

Some researchers have expressed concerns around the safety of nanoparticle use but the authors stress this research is at an early stage and extensive safety trials will be carried out before any product reaches the market. [emphasis mine]

Following on the notion of safety and gargling silver nanoparticles, coincidentally, there was another news item also dated March 8, 2012 on Nanowerk, this one about the impact that nanoparticles may have on nutrient uptake,

Nanoparticles are everywhere. From cosmetics and clothes, to soda and snacks. But as versatile as they are, nanoparticles also have a downside, say researchers at Binghamton University and Cornell University in a recent paper published in the journal Nature Nanotechnology (“Oral exposure to polystyrene nanoparticles affects iron absorption”). These tiny particles, even in low doses, could have a big impact on our long-term health.

According to lead author of the article, Gretchen Mahler, assistant professor of bioengineering at Binghamton University, much of the existing research on the safety of nanoparticles has been on the direct health effects. But what Mahler, Michael L. Shuler of Cornell University and a team of researchers really wanted to know was what happens when someone gets constant exposure in small doses – the kind you’d get if you were taken a drug or supplement that included nanoparticles in some form. [e.g. silver nanoparticles in your mouthwash or on your dentures]

“We thought that the best way to measure the more subtle effects of this kind of intake was to monitor the reaction of intestinal cells,” said Mahler. “And we did this in two ways: in vitro, through human intestinal-lining cells that we had cultured in the lab; and in vivo, through the intestinal linings of live chickens. Both sets of results pointed to the same thing – that exposure to nanoparticles influences the absorption of nutrients into the bloodstream.”

As for why the researchers focused on iron and tested polystyrene nanoparticles (from the news item),

The uptake of iron, an essential nutrient, was of particular interest due to the way it is absorbed and processed through the intestines. The way Mahler and the team tested this was to use polystyrene nanoparticles because of its easily traceable fluorescent properties.

“What we found was that for brief exposures, iron absorption dropped by about 50 percent,” said Mahler. “But when we extended that period of time, absorption actually increased by about 200 percent. It was very clear – nanoparticles definitely affects iron uptake and transport.”

While acute oral exposure caused disruptions to intestinal iron transport, chronic exposure caused a remodeling of the intestinal villi – the tiny, finger-like projections that are vital to the intestine’s ability to absorb nutrients – making them larger and broader, thus allowing iron to enter the bloodstream much faster.

As to whether these changes are good or bad the researchers don’t speculate. They do have plans for more testing,

calcium,
copper,
zinc, and
fat-soluble vitamins A, D, E and K

They don’t mention any changes in the types of nanoparticles they might be testing in future.

In any event, our bodies have changed a lot over the centuries, you just have to visit a pyramid in Egypt or a museum that holds medieval armour to observe that humans were once much shorter than we are today.

Pop culture, science communication, and nanotechnology

A few years back I wrote a paper for the  Cascadia Nanotech Symposium (March 2007 held in Vancouver) called: Engaging Nanotechnology: pop culture, media, and public awareness. I was reminded it of a few days ago when I saw a mention on Andrew Maynard’s, 2020 Science blog about a seminar titled, Biopolitics of Popular Culture being held in Irvine, California on Dec. 4, 2009 by the Institute of Ethics for Emerging Technologies. (You can read more of Andrew’s comments here or you can check out the meeting details here.) From the meeting website,

Popular culture is full of tropes and cliches that shape our debates about emerging technologies. Our most transcendent expectations for technology come from pop culture, and the most common objections to emerging technologies come from science fiction and horror, from Frankenstein and Brave New World to Gattaca and the Terminator.

Why is it that almost every person in fiction who wants to live a longer than normal life is evil or pays some terrible price? What does it say about attitudes towards posthuman possibilities when mutants in Heroes or the X-Men, or cyborgs in Battlestar Galactica or Iron Man, or vampires in True Blood or Twilight are depicted as capable of responsible citizenship?

Is Hollywood reflecting a transhuman turn in popular culture, helping us imagine a day when magical and muggle can live together in a peaceful Star Trek federation? Will the merging of pop culture, social networking and virtual reality into a heightened augmented reality encourage us all to make our lives a form of participative fiction?

During this day long seminar we will engage with culture critics, artists, writers, and filmmakers to explore the biopolitics that are implicit in depictions of emerging technology in literature, film and television.

I’m not sure what they mean by biopolitics, especially after the lecture I attended at Simon Fraser University’s downtown campus last night (Nov. 12, 2009), Liminal Livestock. Last night’s lecture by Susan Squier highlighted (this is oversimplified) the relationship between women and chickens in the light of reproductive technologies.  From the lecture description,

Adapting SubRosa Art Collective’s memorable question, this talk asks: “What does it mean, to feminism and to agriculture, that women are like chickens and chickens are like women?” As liminal livestock, chickens play a central role in our gendered agricultural imaginary: the zone where we find the “speculative, propositional fabric of agricultural thought.” Analyzing several children’s stories, a novel, and a documentary film, the talk seeks to discover some of the factors that help to shape the role of women in agriculture, and the role of agriculture in women’s lives.

Squier did also discuss reproductive technologies at some length although it’s not obvious from the description that the topic will arise. She discussed the transition of chicken raising as a woman’s job to a man’s job which coincided with the rise of  chicken factory farms. Squier also noted the current interest in raising chickens in city and suburban areas without speculating on possible cultural impacts.

The lecture covered  selective breeding and the shift of university  poultry science departments from the study of science to the study of increasing chicken productivity, which led to tampering with genes and other reproductive technologies. One thing I didn’t realize is that chicken eggs are used for studies on human reproduction. Disturbingly, Squier talked to an American scientist, whose work concerns human reproduction, who moved to Britain because the chicken eggs are of such poor quality in the US.

The relationship between women and chickens was metaphorical and illustrated through popular children’s stories and pop culture artifacts (i.e. poultry beauty pageants featuring women not chickens) in a way that would require reproducing far more of the lecture than I can here. So if you are interested, I understand that Squier does have a book about women and chickens being published although I can’t find a publication date.

Squier’s lecture and the meeting for the Institute of Ethics for Emerging Technologies present different ways of integrating pop culture elements into the discussion about science and emerging technologies. Since I’m tooting my horn, I’m going to finish with my thoughts on the matter as written in my Cascadia Nanotechnology Symposium paper,

The process of accepting, rejecting, or changing new sciences and new technologies seems more akin to a freewheeling, creative conversation with competing narratives than a transfer of information from experts to nonexperts as per the science literacy model.

The focus on establishing how much awareness the public has about nanotechnology by measuring the number of articles in the newspaper or items in the broadcast media or even tracking the topic in the blogosphere is useful as one of a set of tools.

Disturbing as it is to think that it could be used for purely manipulative purposes, finding out how people develop their attitudes towards new technologies and the interplay between cognition, affect, and values has the potential to help us better understand ourselves and our relationship to the sciences. (In this paper, the terms science and technology are being used interchangeably, as is often the case with nanotechnology.)

Pop culture provides a valuable view into how nonexperts learn about science (books, television, etc.) and accept technological innovations (e.g. rejecting the phonograph as a talking book technology but accepting it for music listening).

There is a collaborative and interactive process at the heart of the nanotechnology ‘discussion’. For example, Drexler appears to be responding to some of his critics by revising some of his earlier suppositions about how nanotechnology would work. Interestingly, he also appears to be downplaying his earlier concerns about nanoassemblers running amok and unleashing the ‘goo’ scenario on us all. (BBC News, June 9, 2004)

In reviewing all of the material about communicating science, public attitudes, and values, one thing stands out: time. Electricity was seen by some as deeply disturbing to the cosmic forces of the universe. There was resistance to the idea for decades and, in some cases (the Amish), that resistance lives on. Despite all this, there is not a country in the world today that doesn’t have electricity.

One final note: I didn’t mean to suggest the inexorable adoption of any and all technologies, my intent was to point out the impossibility of determining a technology’s future adoption or rejection by measuring contemporary attitudes, hostile or otherwise.

’nuff said for today. Happy weekend!