Why strengthening genomic surveillance is an imperative

Contact Counsellor

Last Updated09/08/2022

Researchers from across the world have made available over 650 complete genome sequences of monkeypox isolates to date in public domain databases including GISAID and GenBank.

The unique code of genetic material of any organism, and determines the characteristic of any organism.
Whole genome sequencing is the process of determining the complete DNA sequence of an organism’s genome at a single time.
The gene composition of novel coronavirus, for instance, is different from that of the influenza virus. Every organism has a unique genome sequence.
Laboratories in various countries have been isolating and sharing the genome sequences of the virus on an international platform.

When viruses multiply, or reproduce, there is a copying mechanism that transfers the gene information to the next generation.
However, no copying mechanism is perfect. When the virus multiplies, there will be small changes, which are called mutations.
These mutations accumulate over time, and after prolonged periods, are responsible for evolution into new organisms.
Within a single reproduction, the changes are extremely minor. More than 95% of the gene structure remains the same.

However, the small changes that occur are crucial to understanding the nature and behaviour of the organism.
Small changes could provide scientists with information about the origin, transmission, and impact of the virus on the patient.
It could also hold clues to the differing effects the virus could have on patients with different health parameters.

The monkeypox virus has a DNA genome of around 2,00,000 base pairs, roughly six times larger than that of SARS-CoV-2.
Like other viruses, the monkeypox virus evolves by the accumulation of genetic errors, or mutations, in its genome when it replicates inside a host.
Being a DNA virus, the monkeypox virus like other poxviruses was believed to have a small rate of accumulating genetic changes compared to viruses with an RNA genome like SARS-CoV-2, which have a much larger rate of mutations.
For poxviruses, this rate is estimated to be as low as a couple of genetic changes every year.

Several mutations that have been identified in the new sequences of the monkeypox virus.
This may have emerged due to interaction between the virus genome and an important family of proteins coded by the human genome known as the Apolipoprotein B Editing Complex (or APOBEC3).
These proteins offer protection against certain viral infections by editing the genome sequence of the virus while it replicates in the cell.
Some researchers suggest that many of the genetic mutations in the monkeypox genomes from the current outbreak are relics of the effect of APOBEC3.

Genomic surveillance of pathogens provides interesting insights by following a molecular approach for contact tracing and understanding the transmission of the virus across the world.
As cases of monkeypox continue to rise, it is therefore important to strengthen the genomic surveillance for the monkeypox virus.