Researchers at the University of Colony, Germany, investigated the asexual reproduction of eybatid mites using genome sequencing techniques.
In partnership with researchers from other international institutions, German scientists have shown that the key behind the evolution without sex of the yield mites may be in evolution independent of its two chromosomal copies: A phenomenon known as the “Meselson effect”.
Since sex is the driving force of evolution, in its absence, organisms are at risk of stagnation and genetic extinction – at least according to predominant evolutionary theory.
But the oribitid mite Platynothrus peltifer It challenges this paradigm: it has been around for over 20 million years, totally without sex.
Assexed mites produce their female descendants from non -fertilized eggs without males. Depending on the mechanism that restores the diploid set of chromosomes, the descent can inherit all or some of the mother’s genetic variants (alleles).
In the yibatid mite, the two copies of the sets of chromosomes evolve independently of each otherallowing new genetic variants to emerge, while retaining important information.
During the investigation, the team observed Notable differences in the Genic expressionnamely that copies of genes are active and to what extent. These differences allow quick responses to environmental changes and provide a selective advantage.
Another mechanism that contributes to genetic diversity is the Horizontal gene transfer (HGT), that is, the movement of genetic material out of the confined barriers of sexual reproduction.
“Horizontal gene transfer can be viewed as the addition of new tools to an existing toolbox. Some seem to help the mite to digest cell walls, thus expanding its food spectrum, ”explained Hüsna Öztoprak, quoted by.
Os Transponable Elements (TE)also known as “jumping genes”, play an important role as they move within the genome. However, its activity differs between the two chromosomal copies and may be active in one and inactive in the other.
“In future research projects, we would like to find out if there are important additional mechanisms for sex without sex,” said researcher Jens Bast, leader of the group Emmy Noether at the University of Colony.
O was published in Science Advances.
