Genetic Engineering

Genetic engineering is “the deliberate modification of the characteristics of an organism by manipulating its genetic material.” In other words, it is now possible to alter the phenotype of an organism by changing its genetic code. Because DNA uses the same base-pairing principle and the same chemicals in all organisms, (A-T C-G) It is possible to take a section of the genome from one organism, and transport it into another.

For example, say you wanted to change the fur colour of the red panda from red to brown, you would take the section of the genome that codes for the protein MC1R from another animal, such as an ordinary panda, and stitch it into the red pandas genetic code while it was developing. Since MC1R filters out red pigment, the panda would be born with brown or black fur. Obviously there is no benefit to non-red red pandas, but malaria resistant mosquitoes or pest resistant plants would come with many benefits.

Probably the most revolutionary breakthrough in the field of genetic engineering was CRISPR-Cas9, a gene editing tool that can be programmed to target stretches of the genome and either shut down or activate certain genes. CRISPR-Cas9 works by using CRISPRs (Clustered Regularly Interspaced Short Palindromic Repeats) which are a type of bacterial defence system. They were discovered in archea, and later in bacteria, by Francisco Mojica. In 2007 CRISPRs were proven to be a defence system against bacteriophage. CRISPRs are a part of bacterial immune systems, repeating genetic code from past invaders, interrupted by spacer sequences to allow the bacteria to recognise and destroy any similar attackers. This is called a prokaryotic immune system. CRISPR-Cas9 uses the same targeting system to find sections of the genome and then uses the enzyme Cas9 to edit them, either by cutting the genome or by correcting flaws and mutations.

In September 2015, some genetic researchers at the Zhang lab found a different and more effective system called CRISPR-Cpf1 that provides more precise and simpler editing tools.


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