Nakai Michiko, Ito Junya, Suyama Ayumi, Kageyama Atsuko, Tobari Yasuko, Kashiwazaki Naomi
Institute of Agrobiological Sciences, National Agriculture and Food Research Organization, Tsukuba, Japan.
Laboratory of Animal Reproduction, School of Veterinary Medicine, Azabu University, Sagamihara, Japan.
Anim Sci J. 2020 Jan-Dec;91(1):e13345. doi: 10.1111/asj.13345.
During mammalian fertilization, sperm is fused with the oocyte's membrane, triggering the resumption of meiosis from the metaphase II arrest, the extrusion of the second polar body, and the exocytosis of cortical granules; these events are collectively called 'oocyte activation.' In all species studied to date, the transient rise in the cytosolic level of calcium (in particular, the repeated calcium increases called 'calcium oscillations' in mammals) is required for these events. Researchers have focused on identifying the factor(s) that can induce calcium oscillations during fertilization. Sperm-specific phospholipase C, i.e., PLC zeta (PLCζ), is a strong candidate of the factor(s), and several research groups using different species obtained evidence that PLCζ is a sperm factor that can induce calcium oscillations during fertilization. However, postacrosomal sheath Tryptophan-Tryptophan (WW)-domain-binding protein (PAWP) was recently shown to have a pivotal role in inducing calcium oscillations in some species. In this review, we focus on PLCζ and PAWP as sperm factors, and we discuss this controversy: Which of these two molecules survives as a sperm factor?
在哺乳动物受精过程中，精子与卵母细胞膜融合，触发减数分裂从中期II阻滞恢复、第二极体排出以及皮质颗粒胞吐；这些事件统称为“卵母细胞激活”。在迄今研究的所有物种中，这些事件都需要胞质钙水平的短暂升高（特别是在哺乳动物中称为“钙振荡”的反复钙增加）。研究人员一直致力于确定在受精过程中能够诱导钙振荡的因素。精子特异性磷脂酶C，即磷脂酶Cζ（PLCζ），是该因素的有力候选者，几个使用不同物种的研究小组获得的证据表明，PLCζ是一种能够在受精过程中诱导钙振荡的精子因子。然而，顶体后鞘色氨酸-色氨酸（WW）结构域结合蛋白（PAWP）最近被证明在某些物种中诱导钙振荡方面起关键作用。在这篇综述中，我们聚焦于PLCζ和PAWP作为精子因子，并讨论这一争议：这两种分子中哪一种作为精子因子留存下来？
