The process by which the monkeypox virus spreads through human populations is accompanied by mutations in repeated stretches of DNA. This helps it rapidly adapt to life in human cells, according to a paper published in the bioRxiv digital library.
A team of molecular biologists led by Sara Monson of the Carlos III Health Institute in Madrid, Spain, has followed the evolution of the MPXV virus as it is transmitted from one patient to another.
The scientists collected samples of the virus from the body ulcers of several patients hospitalized in clinics in Madrid earlier this summer, and completely decoded the genomes of these pathogens. They compared them with similar sequences for several MPXV samples collected in different regions of Africa in the last fifty years.
The analysis showed that the genome of the European MPXV strains contained mutations in repetitive regions within three genes that are responsible for producing proteins associated with monkeypox virus penetration into its victim cells as well as suppression of cellular self-defense systems.
Further study of these DNA blocks indicated that these repeats, which scientists call genetic accordions, play a role in the evolution of not only MPXV but also many other smallpox viruses. Their structure affects the shape and activity of the proteins encoded by these three genes. This allows smallpox viruses to alter the workings of the sections of DNA that infect cells.
The large number of repeats in the genome of MPXV, as well as other smallpox viruses, allows them to adapt quickly and flexibly to infect new victim species. Typically, these repeats in the DNA structure are usually ignored in research, but in this case, they play a key role in the evolution of smallpox viruses, the Spanish scientists noted.