In the battle of the sexes, males appear to have the innovative edge--from a genetic standpoint, at least. Scientists are finding that the testes are more than mere factories for sperm; these organs also serve as hotspots for the emergence of new genes, the raw material for the evolution of species. Using fruit flies, a Rockefeller University team has gained key insight into how nature's attempts at innovation play out during the development of sperm. In research published online on August 16, 2019 in eLife, they mapped the presence of mutations to DNA at the single-cell level, and the activity of new genes arising from such changes. The open-access article is titled “Testis Single-Cell RNA-Seq Reveals the Dynamics of De Novo Gene Transcription and Germline Mutational Bias in Drosophila.” "Our work offers an unprecedented perspective on a process that enables living things to adapt and evolve, and that ultimately contributes to the diversity of life on Earth," says Rockefeller Assistant Professor Li Zhao, PhD, who led the research. In recent years, studies in animals from flies to humans have turned up a number of young genes that originated in the testes. These and other discoveries suggest that the testes rank among the most productive sites in the body--male or female--for genetic innovation. This mass production of genetic novelties comes with significant risks, however. In humans, for example, a father's sperm acquires two to three times more new mutations than do a mother's eggs in the course of normal development, leaving the sperm riddled with genetic mistakes. In some cases, such mistakes may harm the faather’s offspring, or even derail the prospect of fatherhood altogether.Login Or Register To Read Full Story