Loss Of Chromodomain of Male-Specific Lethal 3 (MSL3) Does Not Affect Spermatogenesis in Rodents.

Male-specific lethal (MSL3) is a member of the Dosage Compensation Complex in Drosophila. It is required for transcriptional upregulation of genes on the X chromosome in males to equal that of females. Even though the dosage complex is carried out differently in mammals, Msl3 is conserved in humans. Intriguingly, Msl3 is expressed in the undifferentiated cells from Drosophila to humans, including in spermatogonia of macaque and humans. During Drosophila oogenesis, Msl3 is required for meiotic entry. However, its role in meiotic entry in other organisms has not been explored. Using mouse spermatogenesis as a model system, we probed for the role of Msl3 in the meiotic entry. We found that MSL3 is expressed in mouse testes in meiotic cells in contrast to flies, primates, and humans. Further, using a newly generated MSL3 conditional knock-out mouse line, we found no spermatogenesis defects within the seminiferous tubules of the KOs.MSL3 mutants were also viable and fertile, suggesting that MSL3 is dispensable for rodent gametogenesis.