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; MARIN-BRIGGILER CI
Libro:
Infertility in the Male (Fourth Edition).
Editorial:
Cambridge University Press
Referencias:
Lugar: Cambridge, Gran Bretaña; Año: 2008; p. 104 - 121
Resumen:
El capítulo citado no tiene abstract o resumen oficial. Fragmento del capítulo: “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 fi rst bind to the extracellular matrix that surrounds the egg, called 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. Th e spermatozoon reaches the perivitelline space, binds and fuses to the egg plasma membrane (oolemma); the sperm head enters the egg cytoplasm (ooplasm), and the sperm nucleus undergoes decondensation. Ultimately, sperm entrance triggers mechanisms to block polyspermia. Each of these steps is schematically represented in Figure 7.1 . Although in the last 30 years some of the mechanisms involved in mammalian fertilization have been elucidated, the molecular basis of human sperm–egg interaction is still not completely known. Defective sperm–ZP interaction and disordered ZP-induced AE have been identifi ed 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 [ 1 , 2 ]. An understanding of the molecular mechanisms underlying the processes by which spermatozoa reach, recognize, bind to, 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 regulation of male fertility . This chapter aims to present an overview of the current knowledge regarding the molecular mechanisms involved in human fertilization and the components participating in this process. Due to space limitations, most of the original publications on each topic could not be listed. Cited literature is mainly a selection of review and individual articles on recent advances in human reproduction. Reports from studies in animal models are mentioned when strictly needed. For supplementary information, readers should refer to a number of review articles from highly recognized professionals in the field [3–10] .