ATLANTA, Ga. (CBS Atlanta) – A new study shows that only two genes from the Y-chromosome are needed for male reproduction.
Scientist’s findings could help infertile men have children. More specifically, men who cannot produce healthy sperms cells could benefit from treatments based on these findings.
For the study, researchers injected two Y-chromosome genes into mouse embryos that lacked a Y-chromosome. They found that the embryos grew into adult mice that could produce offspring through assisted reproduction techniques.
“Only two Y-chromosome genes are needed to have children with the help of assisted reproduction,” study author Monika Ward, a reproductive biologist at the University of Hawaii in Honolulu, told LiveScience.
Ward explained to LiveScience that past research showed that when a gene called Sry was inserted into mouse embryos that are genetically female, “it changed the fate of the mice, even though they had two X-chromosomes, they developed into males.”
In a trial-and-error process with the new research, researchers added other Y-chromosome genes one at a time into mice that eventually revealed a gene called Eif2s3y, which helped spermatogonia occasionally develop into immature sperm called spermatids.
Spermatids lack the whiplike tails that normal sperm have. These are just round cells.
Although mice with Sry and Eif2s3y are male and can generate sex cells, they cannot have offspring.
Ward and her team injected these spermatids directly into egg cells to see if males with this pair of Y genes could reproduce with assistance. Viable offspring was produced successfully with this method.
“We’re not trying to eliminate Y-chromosomes with our work — or men, for that matter,” Ward told LiveScience. “We’re just trying to understand how much of the Y-chromosome is needed, and for what.”
Ward also explained that they did not test if the males resulting from this method also could have viable offspring but if the males could not conceive the conventional way, their spermatids may also be able to be fertilized with an egg if they were injected directly into them.
The scientists detailed their findings online Nov. 21 in the journal Science.