A genetic basis for a postmeiotic X vs. Y chromosome intragenomic conflict in the mouse. Mus musculus

The Y-encoded multicopy gene Sly has been shown to repress X and Y genes in spermatids, among which are its X-linked homologs Slx and Slxl1, via modulation of post-meiotic sex chromain (PMSC). In this experiment, we compared expression in spermatids from mice that are deficient for Sly (shSLY), for Slx/Slxl1 (shSLX1) or both (shSLX1shSLY). We observed that Slx/Slxl1 has an opposite role to that of Sly, and stimulates expression of X and Y genes in spermatids when Sly is absent. Slx/Slxl1 deficiency rescues the sperm differentiation defects and near sterility caused by Sly deficiency and vice versa. Slx/Slxl1 deficiency also causes a sex ratio distortion towards the production of male offspring that is corrected by Sly deficiency. Overall design: Wild type strain-matched spermatids are used as a control (4 biological replicates), and 3 biological replicate samples are analysed for each genotype of interest (shSLY, shSLX1 and shSLX1shSLY)