Coronavirus Mutation

Recent Chinese research suggests that the SARS CoV 2 has mutated into two stains with the newer strain being more aggressive.

• Strains of SARS CoV 2:

The study published in National Science Review journal reported that there are 2 strains of SARS CoV 2- the ‘S’ strain and the ‘L’ strain. The S strain is the older and weaker strain. The newer L strain is more aggressive and is more common in Wuhan in China than the S strain.

• Selective Pressure:

Selective pressure is the condition due to which certain organisms with a specific phenotype are at an advantage or disadvantage. It is the factor that drives natural selection. The scientists reported that the frequency of S strain is increasing because of weaker selective pressure.

• Frameshift Mutation:

The authors of the paper called the SARS CoV 2 case as a ‘frameshift mutation’. It is a type of genetic mutation in which a number nucleotides are added or deleted (called indel) in a DNA sequence that isn’t divisible by 3. This changes what proteins are coded for by the DNA and synthesised subsequently.