Role of sperm membrane phosphotyrosine proteins on sperm function in domestic and nondomestic felids

Sperm membrane proteins phosphorylated on tyrosine residues were identified in four populations of felids: (1) normospermic domestic cats ({dollar}>{dollar}60% normal spermatozoa/ejaculate); (2) teratospermic domestic cats ({dollar}{dollar} 0.05). In the domestic cats, the inhibitors tyrphostin and genistein inhibited: (1) the ZP-induced AR in a concentration dependent manner; and (2) penetration into the inner ZP and perivitelline space. Similarly, leopard cats spermatozoa also were prevented from penetrating the inner half of ZP and perivitelline space following tyrphostin exposure.; These results indicate that: (1) a 95 kDa tyrosine phosphorylated sperm protein is conserved across species; (2) changes in phosphorylation of sperm proteins regulates capacitation; (3) phosphorylation of these proteins is compromised in teratospermic males; (4) capacitation, AR and oocyte penetration are modulated by a tyrosine kinase mediated mechanism in felids.