Sperm Penetration of the Vitelline Envelope of Sicyonia ingentis Eggs is Mediated by a Trypsin‐like Lysin of Acrosomal Vesicle Origin

Abstract

The sperm of the decapod crustacean Sicyonia ingentis are nonmotile, unistellate cells. At spawning, mated females release both stored sperm and eggs. The sperm bind, via the tip of their anterior appendage, to the egg's vitelline envelope (VE), rapidly undergo acrosomal exocytosis, and penetrate the VE. In the present study we used protease inhibitors to show that sperm penetration of the VE is due to the activity of a sperm trypsin‐like protease(s). Sperm extracts contained several proteases when examined using gelatin‐substrate SDS‐PAGE, with two major bands of relative molecular weight 46 kD and 30 kD. Using fluorescent peptidyl‐MCA substrates, sperm extract showed trypsin‐like and aminopeptidase‐like activities, but no chymotrypsin‐like activity. Sperm extracts were found to degrade isolated VEs. Using soybean trypsin inhibitor and anti‐inhibitor antibodies, protease was localized at the light and electron microscope levels to the acrosome remnants of reacted sperm.

Integrative analysis of sperm ultrastructure and molecular genetics supports the phylogenetic positioning of the sympatric rock shrimps Sicyonia dorsalis and Sicyonia typica (Decapoda, Sicyoniidae)

“…Although these shrimps are diverse and frequently reported, studies of sperm ultrastructure have been published only for Sicyonia carinata (Brünnich 1768) (Medina et al 1994a) and Sicyonia ingentis (Burkenroad 1938) (Kleve et al 1980). For the latter, detailed descriptions of the acrosome reaction (Clark et al 1981;Griffin et al 1987;Clark and Griffin 1988;Wikramanayake et al 1992;Chen et al 1994;Baldwin et al 1998), vas deferens morphology (Subramoniam 1995), polar body formation in oocytes (Hertzler 2002), and spermiogenesis (Shigekawa and Clark 1986) have been published. Spermiotaxonomy has become a very efficient tool in the resolution of taxonomic issues involving phylogenetic relationships among decapod crustaceans (Jamieson 1991(Jamieson , 1994Medina et al 1994a, b;Medina 1995a;Tudge 2009).…”

Research frontiers in penaeid shrimp reproduction: Future trends to improve commercial production

“…Fertilization begins when spermatozoal spike recognizes and attaches itself to the egg coat (Clark et al, 1981;Wikramanayake and Clark, 1994). This initial contact is facilitated by the affinity of receptors on the spike tip for specific vitelline envelope ligands of the oocytes (Chen et al, 1994). A visible acrosomal reaction (AR) takes place, which consists of biochemical, ionic, and morphological changes in the acrosomal complex necessary for spermatozoal incorporation into the egg to complete successful fertilization (Gwo, 2000).…”