DNA from ancient viruses may be important for growth of embryo in womb, study suggests

New Delhi: DNA from ancient viruses that form a part of the human genome may be contributing in the early development of an embryo in the womb, according to a study.

Ancient viral DNA, also called 'transposable elements', are said to have infected our primate ancestors millions of years ago, remnants of which are present in the human genome.

Researchers, led by those at Helmholtz Munich and Ludwig-Maximilians-Universität, Germany, found that once dismissed as the "dark side" of the genome, remnants of the ancient viral DNA are re-activated during the first hours and days following fertilisation -- when a sperm and egg unite and pregnancy starts.

The findings, published in the journal Cell, are "significant because these early-stage cells can differentiate into all body cell types", said corresponding author Maria-Elena Torres-Padilla, director of the Institute for Epigenetics and Stem Cells, Helmholtz Munich.

"By understanding how these cells regulate ancient viral elements, we gain crucial insights into the mechanisms of cellular plasticity," Torres-Padilla said.

Cell plasticity refers to how cells can change their identity and function in response to changes in environment. It is seen in varied contexts, including development of an embryo, healing of a wound and also cancer.

For the study, the authors created a map of an embryo, by comparing multiple ones from different mammal species, including mouse, cow, pig, rabbit, and the non-human primate, rhesus macaque.

The team found that the ancient viral genetic material -- previously thought to be extinct -- are re-expressed in embryos of mammals, the researchers found.

"Our research uncovered that transposable element activation is a distinctive feature of early embryos in several mammalian species," Torres-Padilla said.

"This study sets the stage for future research into specific regulatory elements, with broad implications for health, disease, and how manipulating these elements could impact cellular processes," the corresponding author said.