Wassarman Paul M, Litscher Eveline S
Department of Cell, Developmental, and Regenerative Biology, Icahn School of Medicine at Mount Sinai, One Gustave L. Levy Place, New York, NY 10029, USA.
Trends Dev Biol. 2022;15:1-13.
Fertilization in mammals is initiated by species-restricted binding of free-swimming sperm to the unfertilized egg's thick extracellular matrix, the zona pellucida (ZP). Both acrosome-intact and acrosome-reacted sperm can bind to the ZP, but only the latter can penetrate the ZP, reach the egg's plasma membrane, and fuse with plasma membrane (fertilization) to produce a zygote. Following fertilization, the ZP is modified by cortical granule components such that acrosome-intact and acrosome-reacted sperm are unable to bind to fertilized eggs. Here we review some of the evidence that bears directly on the involvement of two mouse ZP proteins, mZP2 and mZP3, as receptors for binding of mouse sperm to unfertilized eggs and address some contentious issues surrounding this important initial step in the process of mammalian fertilization.
在哺乳动物中，受精始于自由游动的精子与未受精卵的厚细胞外基质——透明带（ZP）进行物种特异性结合。顶体完整和顶体反应的精子都能与透明带结合，但只有后者能穿透透明带，到达卵质膜，并与质膜融合（受精）以产生受精卵。受精后，透明带会被皮质颗粒成分修饰，使得顶体完整和顶体反应的精子都无法与受精卵结合。在此，我们综述了一些直接证明小鼠的两种透明带蛋白mZP2和mZP3作为小鼠精子与未受精卵结合的受体所涉及的证据，并讨论了围绕哺乳动物受精过程中这一重要起始步骤的一些有争议的问题。
