The Y chromosome is a symbol of maleness, present only in males and encoding genes important for male reproduction. But a new study has shown that live mouse progeny can be generated with assisted reproduction using germ cells from males which do not have any Y chromosome genes. This discovery adds a new light to discussions on Y chromosome gene function and evolution. It supports the hypothesis that Y chromosome genes can be replaced by that encoded on other chromosomes.
Two years ago, the UH team led by Monika A. Ward, Professor at the Institute for Biogenesis Research, John A. Burns School of Medicine (JABSOM), University of Hawai‘i-Mānoa, demonstrated that only two genes of the Y chromosome, the testis determinant factor Sry and the spermatogonial proliferation factor Eif2s3y, were needed for males to sire offspring with assisted fertilization. Now, the same team, with a collaborating researcher from France, Michael Mitchell (INSERM, Marseille), took a step further and produced males completely devoid of the entire Y chromosome.
In this new study scheduled for online publication in the journal Science on January 28, 2016, Ward and her UH colleagues describe how they generated the “No Y” males, and define the ability of these males to produce gametes and sire offspring.