Organization and modifications of sperm acrosomal molecules during spermatogenesis and epididymal maturation

Abstract

The mammalian acrosome is a highly specialized organelle overlying the anterior part of the sperm nucleus and contains a variety of proteins, including hydrolytic enzymes and matrix molecules. Functionally, the anterior acrosome is involved in the acrosome reaction or sperm-zona pellucida interaction, while the equatorial segment (posterior acrosome) is involved in sperm-egg fusion. The acrosome is formed during spermiogenesis, during which associated molecules are transported from the Golgi apparatus and organized. Many of the molecules thus arranged gradually become compartmentalized during sperm passage through the epididymis. Some of them are further modified during the fertilization process. The findings indicate that acrosomal molecules are not only restricted to a specific region (domain) of the acrosome but also undergo ongoing relocation in a stage-specific manner during sperm maturation in the testis and epididymis. Such maturation-associated modifications are considered essential for sperm molecules to reach the correct or final site before fertilization. This review focuses on the organization and modifications of the acrosomal molecules as well as their compartmentalization within the acrosome.

Singular features of fertilization and their impact on the male reproductive system in eutherian mammals

“…Perhaps reflecting a reorganization of its content (Yoshinaga & Toshimori 2003, Olsen et al 2004, Buffone et al 2008, although not visible in the rat or in man, this has been observed in the guinea pig, chinchilla, loris, rhesus monkey, rabbit, hyrax and white-tailed rat (Mystromys albicaudatus). As noted, the eutherian acrosome is not merely a bag of enzymes in that the fenestrated carapace usually first tethers the sperm head to the zona.…”

The Epididymis: Embryology, Structure, Function And Its Role In Fertilization And Infertility

“…The sperm acrosome is a highly specialized organelle overlying the anterior part of the sperm nucleus. The acrosome contains a number of hydrolytic enzymes that are believed to be required for fertilization (Yoshinaga & Toshimori, 2003).…”

“…These molecules induce changes in the acrosomal proteins of the spermatozoa by maturationwww.intechopen.com dependent modifications attributed to glycosylation/deglycosylation and/or proteolytic processing during epididymal maturation (Yoshinaga & Toshimori, 2003). The acrosomal human SP-10 protein decreases from 45 kDa to 18-25 kDa as a result of the proteolytic process when the spermatozoa pass into the caput epididymis.…”

Digital holographic microscopy for the evaluation of human sperm structure

“…Golgi-derived secretory vesicle on the proximal hemisphere of the head containing an array of hydrolytic enzymes used for digesting the zona pellucida during penetration (Gerton, 2002;Yoshinaga and Toshimori, 2003); and the perinuclear theca, a rigid capsule composed of disulfide bond stabilized structural proteins amalgamated with various other protein molecules (Oko, 1995).…”