Master Manipulators: Refining the Genetic Process

by Anna Danso-Amoako

CRISPR technology (Wiki Commons)

Humans have a long history with the manipulation of genes in organisms, beginning in 12,000 BC with artificial selection of plants and animals. This process involves influencing the breeding of organisms to ensure desired phenotypes, visible attributes, are present in the offspring. An example of this is breeding animals such as cows for their volume of milk. The parents would be chosen for the large amount of milk they would be able to produce. When bred together, they would produce offspring that carries the high milk volume gene as the gene is inherited by the offspring. Through many generations of selective breeding, the overall population should produce large volumes of milk and create breeds such as Friesian cows.

Gene manipulation eventually became more advanced due to the discovery of restriction enzymes in 1968. Secreted as a protein from bacteria, they are essential towards the modification of genetic material as they have the ability to “cleave” DNA foreign to themselves. Restriction enzymes from different bacteria are able to identify short sequences of nucleotides bases present within DNA and after identification of these sequences, the enzymes operate as biological scissors by acting as a catalyst to the hydrolysis of phosphodiester bonds between the nucleotides removing the sequence from the DNA.

While different bacteria produce restriction enzymes that identify different sequences, restriction enzymes can be classified into four different groups numbered one to four but it is the type II restriction enzyme which is of greatest importance towards genetic modification, as they edit the DNA in specific regions compared to the random nature in which the other restriction enzymes alter DNA. After the enzymes were refined by scientist Hamilton Smith, they were used by Stanley Cohen and Herbert Boyer to cut DNA into segments that were later rejoined to be inserted into E.coli which reproduced producing DNA that had been successfully altered, thus forming the basis of genetic engineering.

However the our attempts to further refine the genetic process have only become more refined with the advanced and controversial with the invention of CRISPR technology. Standing for Clustered Regularly Interspaced Short Palindromic Repeats, they were first observed by Japanese scientists studying E.coli but their biological importance was unknown. That is until a group of food scientists studying bacteria within the use of yogurt production made a breakthrough: they served an important function with the immune system within bacteria. When bacteria are under threat from viruses, they produce enzymes which aid in the destruction of the virus in a similar cleaving mechanism to restriction enzymes. However, fragments of the viruses’ genetic information are stored within the CRISPR regions of the bacteria. If the bacteria is under attack by a virus it can send specific enzymes known as Cas9, which hold the viral genetic information and search the virus for material which matches it to be cleaved. This process has been altered to be used in gene editing by providing the Cas9 with false RNA which resulted in the enzyme successfully identifying and destroying it. In addition to this Cas9 can also be used to silence certain genes to prevent them from functioning.

Why is this so revolutionary if we already have technology similar to it that can carry out the same function as CRISPR? Quite simply, the ease at which editing could be possible is unmatched by any other method of manipulation. CRISPR can be done in hours and costing less than £100 the accessibility to which this highly specialised genetic modification technology is available is unprecedented. While searching, I found it was indeed possible to buy your own CRISPR Kits. They are sold by a company known as The ODIN, run by a controversial biohacker Josiah Zayner who demonstrated perfectly the implications of such accessible technology could have by injecting himself with CRISPR modified for muscle enhancement in the hopes of building his bicep. While it didn’t actually work, the biological community has certainly reached a grey area in regards to how the future applications of technology such as CRISPR will look. It enables scientists to have the ability to change and edit out parts of the DNA seen as undesirable. In some circumstances this is an a gene that is widely accepted as a liability such as a fatal disease such as Huntington’s however the lines become more blurred when we consider what should actually be cured and if it is our place to determine this.

Modern science brings about change that is revolutionary but poses questions we may never be fully able to answer but with the technology already accessible it becomes increasingly pertinent that we must try. The future will no doubt be filled with possibilities in which we will be able to change life beyond recognition however we mist not lose sight of our ethical standards to ensure that science doesn’t become a force to fear.