Gene Editing Can Make Chickens Resistant to Bird Flu

    For decades genetic modification has been occurring, and just recently have we found a way to soon stop the spread of disease on farms. This issue comes after the recent outbreak which affected the poultry industry when millions of chickens had to be put down or were killed due to the illness. 

    However, just recently after making some adjustments to a singular gene it was discovered that chickens became resistant to an avian influenza infection. With this knowledge, genetic modification could help in stopping viruses from replicating inside animals and stop them from transmitting different diseases and flus to other animals and people.

    The two images to the right show the injection of vaccines into chickens. Yes, vaccines have been created to help defend against the flu, but we are faced with many issues when it comes to using them. The vaccine is very costly, and the flu/virus is able to adapt so that it can elude the protection the vaccine offers. Therefore, genetic modification would be the best way to fix this issue considering that gene editing has permanent results.

 

    A gene called ANP32A directs chicken cells what they need to do in order to make a protein which the flu viruses rely on so that they can take over those cells. After doing a study with chicken cells grown in a lab it was found that when you eliminate the three ANP32 genes from the chicken cells the virus stopped replicating completely. More testing is being done for other genes due to the fact that could cause problems with chicken developments.

Main Source: 

Gene editing can make chickens resistant to bird flu (sciencenews.org)

Extra Links:

Using gene editing to fight deadly genetic diseases | News | Harvard T.H. Chan School of Public Health

Overcoming Livestock Disease Through Gene Editing

The livestock industry may be on the brink of an effective tool to fight against disease thanks to geneticists at the Roslin Institute in Edinburgh. Professor Eleanor Riley and her team have recently identified the gene in pigs that allows viruses to enter the cell. By removing this gene from a pig's DNA resulted in these animals to become resistant to common diseases like Porcine Reproductive and Respiratory Syndrome Virus (PRRSV) which affects the livestock industry roughly $170 million every year. This same approach has also been used at the Roslin Institute to identify the gene that provides resistance against avian flu in chickens. With the final trail yet to be published, the livestock industry is anxious to see the results. According to Eleanor Riley, it would only take three to five years to produce these disease resistant animals into the livestock community. This could potential save farmers millions in biosecurity, animal deaths and possibly increase the food production in the world. With the population of humans already over 7.0 billion there are more mouths to feed than ever before. By increasing livestock resistance to fatal diseases, this could potentially be a significant result for much more than just the farming community.

Article: https://www.theguardian.com/science/2018/mar/17/scientists-on-brink-of-overcoming-livestock-diseases-through-gene-editing
Additional Information: https://www.theguardian.com/environment/2018/jan/15/british-supermarket-chickens-show-record-levels-of-antibiotic-resistant-superbugs

Genetic Structure of Avian Influenza Viruses from Ducks of the Atlantic Flyway of North America

https://wwwnc.cdc.gov/eid/article/12/11/06-0652-f1

Original Article

Further Information

Ducks, like most wild avian species are hosts to a pool of influenza A viruses. Even though scientists have a growing number of avian influenza virus (AIV) genome sequences, their understanding of the genetic structure and transmission in waterfowl in North America is still limited. The Atlantic flyway, located on the eastern shore of the United States, is lacking on knowledge about AIV. To further their knowledge, scientists analyzed 109 AIV genome sequences from waterfowl from the Atlantic flyway to determine their genetic structure, observe gene flow compared to other birds in various locations along the flyway.. The experiment included 25 AIVs from ducks gathered in Newfoundland, Canada, and 84 duck AIVs dispersed throughout Atlantic flyway. High amounts of diversity of viral genes and genomes were identified in the 109 samples tested. Transmission between continents were very small, roughly 2%, while the rate of transmission between North American flyways is much more abundant, roughly 75% of the genes could be linked to genes found in the other three North American flyways, namely the Mississippi, Central, and Pacific flyways.

The take home message of this article is that AIV, like most avian viruses, are spread through close contact and proximity. It is expected that most of the genes and genomes would be similar or linked in a specific flyway since most ducks migrate within species and stay in relatively close proximity as they travel up and down the flyway. The reason the rate between contents are so low is because the only time the two birds are in contact during mating, this only happens in some species, or if a flock is blown off course by a strong trade wind.

Possible New Tactic in Fight Against Influenza

Influenza is one of the most common viruses to affect humans. Some people think of the flu as nothing more than an inconvenience that becomes a possibility when the weather starts to turn-however, there are other, more sinister strains of flu than the seasonal flu, and to the elderly, the very young, people with certain diseases, and the immune impaired, even the seasonal flu can mean anything from an lengthy, expensive hospital stay, to complications such as pneumonia, to a death sentence.
There are three main types of flu virus-Influenza A, B, and C. Influenza B and C only affect humans, are usually mild, and don't cause epidemics. Influenza A can cross between species, and has many subtypes, denoted by H and N proteins. Bird flu, swine flu, and seasonal flu are all A subtypes. Swine flu, seasonal flu, and Influenza B are usually included in annual flu vaccines. A subtypes are the biggest threat to humans, and now, scientists at the University of Texas at Austin have figured out a secret to their reproduction and a possible key to slowing it down. Human cells produce a protein called DDX21, which blocks reproduction of the A subtypes by binding to the virus's PB1 protein, which the virus needs to replicate. Unfortunately, the virus also makes a protein called NS1 to bind to and block the DDX21 protein. The NS1 protein also proves to be integral to several other functions of the virus. Professor Robert Krug believes that developing an anti-viral drug that attacks the NS1 protein could be a key to fighting the flu, which causes somewhere between 3 and 49 thousand deaths in the US each year. A subtypes of Influenza have a habit of forming resistances to anti-viral drugs, but all we can do is try to stay ahead of it each season to prevent as many deaths as possible.

(Secondary article: http://www.cdc.gov/flu/about/viruses/types.htm )