Pyruvate kinase M in germ cells is essential for sperm motility and male fertility but not spermatogenesis

Abstract

AbstractMale germ cells employ specific metabolic pathways throughout their developmental stages. In a previous study, we discovered heightened expression of pyruvate kinase M (PKM), a pivotal glycolytic enzyme, in spermatogonia and spermatids. To gain deeper insights into PKM’s roles in spermatogenesis, sperm function, and male fertility, we engineered a conditional-knockout mouse model (Pkm-vKOmice) to selectively disrupt thePkmgene within germ cells. Despite maintaining regular testicular histology and sperm morphology, the malePkm-vKOmice were infertility, characterized by significant impairments in sperm motility and adenosine triphosphate (ATP) generation. In addition,Pkm-nullspermatozoa exhibited similar deficits in protein tyrosine phosphorylation linked to capacitation, as well as compromised performance inin vitrofertilization experiments. To conclude, PKM’s presence is not obligatory for the entirety of spermatogenesis in male germ cells; however, it emerges as a critical factor influencing sperm motility and overall male fertility.