Fertilization-induced Glycosidase Release and Interspecific Sperm Competition in Ascidians

Autor:	Charles C. Lambert
Rok vydání:	2001
Předmět:	endocrine system urogenital system Ascidia nigra media_common.quotation_subject Heterologous Interspecific competition Biology Polyspermy Sperm Competition (biology) Cell biology Human fertilization embryonic structures Sperm competition reproductive and urinary physiology media_common
Zdroj:	The Biology of Ascidians ISBN: 9784431669845
DOI:	10.1007/978-4-431-66982-1_5
Popis:	Most ascidian sperm bind to vitelline coat (VC) N-acetylglucosamine residues. The early block to polyspermy involves release of a lipid linked N-acetylglucosaminidase from the follicle cell surface. This highly mannosylated protein then binds to the VC preventing all sperm but the earliest from binding. Release of the enzyme is mediated by tyrosine phosphorylation of phospholipase C. Fertilization is generally species specific but enzyme release is not; sperm from many species of ascidians can induce enzyme release from heterologous eggs follicle cells. This non-specific enzyme release is the basis for interspecific sperm competition. Eggs of Ascidia nigra, A. sydneiensis or Phallusia julinea first inseminated with each other’s sperm followed by homologous sperm 5 minutes later show declines in fertilization of up to 44 percent. This interspecific sperm competition may be partially responsible for the differential abundance of ascidians in communities, as sperm from one species can sabotage the eggs of a second species and thus reduce the competition for space.
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_________::cd3cdff3eae6628b72e49644a43608f5 https://doi.org/10.1007/978-4-431-66982-1_5 Zobrazit plný text záznamu