IBYME   02675
INSTITUTO DE BIOLOGIA Y MEDICINA EXPERIMENTAL
Unidad Ejecutora - UE
capítulos de libros
Título:
An overview on the molecular mechanisms involved in human fertilization
Autor/es:
VAZQUEZ-LEVIN MH; MARÍN BRIGGILER CI
Libro:
Infertility in the male
Referencias:
Año: 2007;
Resumen:
Fertilization is a fundamental process that involves a highly coordinated sequence of interactions between the female and male gametes, giving rise to a diploid zygote. During this process, spermatozoa that have successfully completed spermatogenesis, epididymal maturation, and transport through the female reproductive tract, first bind to the extracellular matrix that surrounds the egg, the Zona Pellucida (ZP). Sperm binding to ZP glycoproteins triggers sperm Acrosomal Exocytosis (AE), involving fusion of the sperm plasma and outer acrosomal membranes and the release of the content from the acrosomal granule; these components, in conjunction with the hyperactivated vigorous motility, help sperm penetration through the ZP. Finally,  spermatozoa reach the perivitelline space, bind and fuse to the egg plasma membrane (Yanagimachi, 1994). Although in the last 30 years some of the mechanisms involved in mammalian fertilization have been elucidated, the molecular bases of human sperm-egg interaction are still not completely known. Defective sperm-ZP interaction and disordered ZP-induced AE have been identified as major causes of fertilization failure in standard in vitro fertilization (IVF) procedures performed in couples under infertility treatment, and a major contribution to this outcome has been attributed to abnormalities in the male gamete (Liu and Baker, 2000; Liu and Baker, 2003). Therefore, the understanding of the molecular mechanisms underlying the processes by which spermatozoa reach, recognize, bind and fuse with the egg will provide new tools for the improvement of current methods of treatment and diagnosis of male infertility, as well as methods for male fertility regulation. In the present chapter an overview on the molecular mechanisms involved in human fertilization and the components participating in this process are presented.