What is gene editing?

Genetically modified pigs are resistant to the world's costliest livestock diseases that causes breathing trouble, death among young animals as well as causing pregnant sows to lose their litter, a study has found. According to the study, the modified animals were not affected with Porcine Reproductive and Respiratory Syndrome (PRRS) – a killer virus which costs the worldwide farming industry billions per year. The virus infects pigs using a receptor on their cells' surface called CD163. The study is published in Journal of Virology. 

The researchers focused on the section of the receptor that the virus attaches to, leaving the rest of the molecule intact. The pigs were then exposed to the virus, but scientists found no traces of the infection in the animals after conducting blood tests. Removing only a section of CD163 allowed the receptor to retain its ordinary function in the body and reduced the risk of side effects.

According to ghr.nlm.nih.gov, genome editing (also called gene editing) is a group of technologies that give scientists the ability to change an organism's DNA. These technologies allow genetic material to be added, removed, or altered at particular locations in the genome. Several approaches to genome editing have been developed. 

A recent one is known as CRISPR-Cas9, which is short for clustered regularly interspaced short palindromic repeats and CRISPR-associated protein 9. The CRISPR-Cas9 system has generated a lot of excitement in the scientific community because it is faster, cheaper, more accurate, and more efficient than other existing genome editing methods. CRISPR-Cas9 was adapted from a naturally occurring genome editing system in bacteria. 

The bacteria capture snippets of DNA from invading viruses and use them to create DNA segments known as CRISPR arrays. The CRISPR arrays allow the bacteria to "remember" the viruses (or closely related ones). If the viruses attack again, the bacteria produce RNA segments from the CRISPR arrays to target the viruses' DNA. The bacteria then use Cas9 or a similar enzyme to cut the DNA apart, which disables the virus.

RNA or ribonucleic acid, a nucleic acid present in all living cells. Its principal role is to act as a messenger carrying instructions from DNA for controlling the synthesis of proteins, although in some viruses RNA rather than DNA carries the genetic information.