Madrid, 26 January. (EUROPA PRESS). Many organisms, including insects, amphibians and yeasts, use sex pheromones to attract people of the opposite sex, but what happens to sex pheromones when new species arise?
A new study, published on Tuesday in "PLOS Biology" by Taisuke Seike and Hironori Niki, at the National Institute of Genetics in Japan, and Chikashi Shimoda from Osaka City University, Japan, researches sex pheromones in the Schizosaccharomyces pombe decay yeast revealing an asymmetric pheromone recognition system in which one pheromone acts extremely strictly while the other pheromone is free to experience some degree of diversification, which may lead to a first step towards formation.
New species may occur when two populations can no longer cross, and so-called reproductive isolation that restricts the flow of genes between populations is one of the key mechanisms of species formation. Mutational changes of the pheromone system can affect the ability of men and women to recognize each other, resulting in reproductive isolation; More generally, the loss of pheromone activity may lead to the disappearance of the offspring of the organism. The main mechanisms that stimulate the diversification of pheromones in populations are not well understood.
Both sexes ("Plus" and "Minus") of C. Each of them releases pheromone ("P-Pheromone" and "M-Pheromone"), which binds to the corresponding receptor in opposite sex cells. and the differences between the genes encoding the two pheromones and their receptors in 150 wild strain S. The researchers found that M-pheromone and its receptor were completely invariant while P-pheromone and its receptor were very varied in the strains studied. that such asymmetric diversification of the two pheromones is also observed in the near future -governmental yeasts of the genus "S. Oktospor.
The authors suggest that the "asymmetric" system in fed yeast can allow for flexible adaptation to the mutational changes of pheromones, while preserving the strict recognition of the partners. In fact, the previous study of the authors on yeast degradation "S. Experimentally, several mutations in pheromone and its corresponding receptor may result in reproductive isolation, which in turn may lead to a new species.
"Our discoveries contribute to new insights into the evolutionary mechanisms underlying the diversification of pheromones: organisms can have these systems to create new versions of pheromones, allowing them to stay long enough in the population to develop the adaptations of the receptors, "says Seike," before a complete mutant loss, a second suppressor mutation can be obtained to restore the first defect. "Therefore, the co-evolution of pheromones / receptors can proceed step by step.