Mouse Y-Encoded Transcription Factor Zfy2 Is Essential for Sperm Formation and Function in Assisted Fertilization

Spermatogenesis is a key developmental process allowing for a formation of a mature male gamete. during its final phase,spermiogenesis,haploid round spermatids undergo cellular differentiation into spermatozoa,which involves extensive restructuring of cell morphology,dna,and epigenome. using mouse models with abrogated y chromosome gene complements and y-derived transgene we identified y chromosome encoded zfy2 as the gene responsible for sperm formation and function. in the presence of a zfy2 transgene,mice lacking the y chromosome and transgenic for two other y-derived genes,sry driving sex determination and eif2s3y initiating spermatogenesis,are capable of producing sperm which when injected into the oocytes yield live offspring. therefore,only three y chromosome genes,sry,eif2s3y and zfy2,constitute the minimum y chromosome complement compatible with successful intracytoplasmic sperm injection in the mouse. © 2015 yamauchi et al.