Human PLC? exhibits superior fertilization potency over mouse PLC? in triggering the Ca(2+) oscillations required for mammalian oocyte activation.

ABSTRACT: A sperm-specific phospholipase C-zeta (PLC?) is believed to play an essential role in oocyte activation during mammalian fertilization. Sperm PLC? has been shown to trigger a prolonged series of repetitive Ca(2+) transients or oscillations in oocytes that precede activation. This remarkable intracellular Ca(2+) signalling phenomenon is a distinctive characteristic observed during in vitro fertilization by sperm. Previous studies have notably observed an apparent differential ability of PLC? from disparate mammalian species to trigger Ca(2+) oscillations in mouse oocytes. However, the molecular basis and confirmation of the apparent PLC? species difference in activity remains to be provided. In the present study, we provide direct evidence for the superior effectiveness of human PLC? relative to mouse PLC? in generating Ca(2+) oscillations in mouse oocytes. In addition, we have designed and constructed a series of human/mouse PLC? chimeras to enable study of the potential role of discrete PLC? domains in conferring the enhanced Ca(2+) signalling potency of human PLC?. Functional analysis of these human/mouse PLC? domain chimeras suggests a novel role of the EF-hand domain in the species-specific differences in PLC? activity. Our empirical observations are compatible with a basic mathematical model for the Ca(2+) dependence of generating cytoplasmic Ca(2+) oscillations in mammalian oocytes by sperm PLC?.

SUBMITTER: Nomikos M 

PROVIDER: S-EPMC4023910 | biostudies-literature | 2014 Jun

REPOSITORIES: biostudies-literature