Scientists at the College of Veterinary Medicine, Northwest A&F University in Shaanxi, China were determined to figure out a solution to one of the biggest problems facing dairy farmers around the world: tuberculosis. The scientists concluded their examinations by creating ‘designer cows’ where they were able to be resistant to this infectious disease by simply editing their genes through newly-developed technology called CRISPR, whereby allows scientists globally with access to this software to edit genes to suit the needs to accomplish different objectives (resistance to infectious diseases etc.). This advancement spares farmers from having to kill their cattle to alleviate the spread of the tuberculosis infection to the other animals on site that contribute to the dairy industry in the farm. According to the researchers, the gene led to no adverse effects on the animal, but it did greatly increase TB resistance.
Crispr technology precisely changes target parts of genetic code. Unlike other gene-silencing tools, the Crispr system targets the genome's source material and permanently turns off genes at the DNA level. The DNA cut (known as a double strand break) closely mimics the kinds of mutations that occur naturally, for instance after chronic sun exposure. But unlike UV rays that can result in genetic alterations, the Crispr system causes a mutation at a precise location in the genome. When cellular machinery repairs the DNA break, it removes a small snip of DNA. In this way, researchers can precisely turn off specific genes in the genome.
To carry out the process, the healthy gene used to create a resistance against tuberculosis was inserted into the nucleus of another kind of bovine cell (a fibroblast), taken from a cow foetus. This edited nucleus was then transferred to the egg cell of a cow. The eggs were nurtured in the laboratory, and then fertilised in the lab to form embryos. These were then inserted into the cow and developed and were born as normal. A total of 11 calves with new genes inserted using CRISPR were assessed for resistance to tuberculosis and any adverse genetic effects. From this experiment, it ensured that 11 calves would be able to develop without having the risk to carry or infect other cows which may disturb the farm’s procedures in producing the amount set by external demands - from this advancement, it would also open up many opportunities for other farmers worldwide to use this sort of technology to save money on treatment for their cattle and to produce products more efficiently in the long run.