摘要
Nematode sperm undergo a drastic physiological change during spermiogenesis(sperm activation).Unlike mammalian flagellated sperm,nematode sperm are amoeboid cells and their motility is driven by the dynamics of a cytoskeleton composed of major sperm protein(MSP)rather than actin found in other crawling cells.This review focuses on sperm from Caenorhabditis elegans and Ascaris suum to address the roles of external and internal factors that trigger sperm activation and power sperm motility.Nematode sperm can be activated in vitro by several factors,including Pronase and ionophores,and in vivo through the TRY-5 and SPE-8 pathways.Moreover,protease and protease inhibitors are crucial regulators of sperm maturation.MSP-based sperm motility involves a coupled process of protrusion and retraction,both of which have been reconstituted in vitro.Sperm motility is mediated by phosphorylation signals,as illustrated by identification of several key components(MPOP,MFPs and MPAK)in Ascaris and the characterization of GSP-3/4 in C.elegans.
基金
supported by the National Basic Research Program of China(Nos.2012CB94502,2010CB912303)(to L.M.)
the National Natural Science Foundation of China(Grant Nos.31171337 and 30971648)(to L.M.)
Grant Nos.30871226 and 31071180(to Y.Z.)
supported by the Chinese Academy of Sciences 100-Talents Program.