Why strengthening genomic surveillance is an imperative
- 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.
What is Genome Sequencing?
- 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.
Why are so many genome sequences being isolated?
- 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.
How does it help scientists?
- 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.
Accelerated evolution of Monkeypox
- 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.
Key findings
- 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.
Conclusion
- 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.
Prelims Take Away
- Genome Sequencing
- Monkeypox
- Poxviruses
- DNA
- RNA