Engineering the Livestock of Tomorrow

According to the article “Scientists on brink of overcoming livestock diseases through gene editing”, by Hannah Devlin, UK geneticists at the Roslin Institute in Edinburgh have been making significant progress in genetically engineering disease resistance and resilience into livestock species. Although still in its trial stages, the director at the Roslin Institute, Prof Eleanor Riley, believes that in the very near future, the farming industry will be able to save millions every year once these resistant/resilient animals are successfully introduced into the live stock population. The first and most promising experimental trial is currently producing blue ear disease resistant swine, who may be introduced into the live stock population as soon as in three years’ time. Blue ear disease can cause the effected swine to produce stunted offspring or still births, resulting in significant monetary loss in the farming industry. By identifying the gene that codes for the surface receptor, in pig cells, that the virus needs in order to bind and spread, the scientists at Roslin, were able to select and remove a small section of this gene, therefore causing the link from the blue ear virus to the pig cells to be removed entirely. This in turn means that this small genetic intervention would make the resulting swine immune to this ailment  
                    (pig with blue ear)         

            Furthermore, this type of genetic identification and alteration research is also under way for other significant live stock illnesses, such as the avian flu, oyster herpes, and amoebic gill disease in salmon. Geneticists at Rolsin have also begun investigating the genetic foundation for E coli and campylobacter resilience, as they are believed to be the cause of hundreds of thousands of food poisoning cases in the U.K. alone each year. Yet the public seem slow to come around to the idea of eating genetically modified animals (even though they have had no qualms with GMO crops for decades). However, once they realize the benefits genetically engineered livestock will bring to animal welfare and environmental impact mitigation, both the professionals at the Roslin institute and myself believe, the publics opinion will sway much faster in its favor.

Link to article

 https://www.theguardian.com/science/2018/mar/17/scientists-on-brink-of-overcoming-livestock-diseases-through-gene-editing

And for more on Blue Ear Disease

http://www.pigprogress.net/Health/Health-Tool/diseases/Porcine-Reproductive-and-Respiratory-Syndrome-PRRS-

Genetic Diversity Helps to Limit Infectious Disease

Newly found research by the University of Exeter have found that genetic diversity has helped reduce the risk of spreading diseases by limiting parasite evolution.

Even though this study is not new, the answer to why this happens was newly founded. Researchers used a virus that infected and killed bacteria. By using this virus, they could study the effects host diversity had on disease spread. The bacteria defended themselves by using a defense system that they have called CRISPR-Cas. CRISPR-Cas captures random DNA fragments from the virus, thus creating a ‘genetic memory’ of some sort. Now because each bacteria will copy different DNA fragments from the virus, this causes a diversity of bacteria to be formed.

In order for the researchers to see if and why diversity limits the spread of disease, they isolated individual bacteria and grew them in monoculture or mixed them together with other bacteria of diverse populations before exposing them to the virus. The virus spread on the monocultures because the virus was eventually able to outgrow and overcome the CRISPR-Cas immunity. The mixed populations were able to overcome the virus and the virus eventually went extinct; this is because the bacteria had a much larger diversity and were able to overcome the virus all together by herd immunity.

Dr. Stineke van Houte recalls: "Viruses could spread on monocultures but when the individual bacteria were mixed together, the virus went extinct very rapidly. This revealed a strong monoculture effect in our experimental system."

I think this article was very interesting in proving that different variations of bacteria can overcome a virus when they are mixed together. This shows that diversity is good when it comes to bacteria but it could also become harmful if they are harmful bacteria. The mixture of bacteria were able to survive because they were able to increase the immunity of the population as a whole.