Jiménez-Movilla María, Hamze Julieta G, Romar Raquel
Department of Cell Biology and Histology, Faculty of Medicine, University of Murcia, Murcia, Spain.
Biomedical Research Institute of Murcia (IMIB-Arrixaca), Murcia, Spain.
Front Cell Dev Biol. 2021 May 19;9:662032. doi: 10.3389/fcell.2021.662032. eCollection 2021.
Fertilization is a key process in biology to the extent that a new individual will be born from the fusion of two cells, one of which leaves the organism in which it was produced to exert its function within a different organism. The structure and function of gametes, and main aspects of fertilization are well known. However, we have limited knowledge about the specific molecules participating in each of the steps of the fertilization process due to the transient nature of gamete interaction. Moreover, if we specifically focus in the fusion of both gametes' membrane, we might say our molecular knowledge is practically null, despite that molecular mechanisms of cell-to-cell adhesion are well studied in somatic cells. Moreover, between both gametes, the molecular knowledge in the egg is even scarcer than in the spermatozoon for different reasons addressed in this review. Sperm-specific protein IZUMO1 and its oocyte partner, JUNO, are the first cell surface receptor pair essential for sperm-egg plasma membrane binding. Recently, thanks to gene editing tools and the development and validation of models, new oocyte molecules are being suggested in gamete fusion such as phosphatidylserine recognition receptors. Undoubtedly, we are in a new era for widening our comprehension on molecular fertilization. In this work, we comprehensively address the proposed molecules involved in gamete binding and fusion, from the oocyte perspective, and the new methods that are providing a better understanding of these crucial molecules.
受精是生物学中的一个关键过程，因为一个新个体将由两个细胞融合产生，其中一个细胞离开其产生的生物体，在另一个生物体中发挥作用。配子的结构和功能以及受精的主要方面是众所周知的。然而，由于配子相互作用的短暂性，我们对参与受精过程每个步骤的具体分子了解有限。此外，如果我们特别关注两个配子膜的融合，尽管细胞间粘附的分子机制在体细胞中已得到充分研究，但我们可以说我们的分子知识实际上为零。此外，在这两种配子之间，由于本综述中提到的不同原因，卵子中的分子知识比精子中的更为稀少。精子特异性蛋白IZUMO1及其卵母细胞伴侣JUNO是精子-卵质膜结合所必需的第一对细胞表面受体。最近，由于基因编辑工具以及模型的开发和验证，在配子融合中提出了新的卵母细胞分子，如磷脂酰丝氨酸识别受体。毫无疑问，我们正处于一个拓宽对分子受精理解的新时代。在这项工作中，我们从卵母细胞的角度全面探讨了参与配子结合和融合的分子以及能让我们更好理解这些关键分子的新方法。
