title: Epididymal protein Rnase10 is required for post-testicular sperm maturation and male fertility.
abstract: Eutherian spermatozoa are dependent on the environment of the proximal epididymis to complete their maturation; however, no specific epididymal factors that mediate this process have so far been identified. Here, we show that targeted disruption of the novel gene Rnase10 encoding a secreted proximal epididymal protein in the mouse results in a binding defect in spermatozoa and their inability to pass through the uterotubal junction in the female. The failure to gain the site of fertilization in the knockout spermatozoa is associated with a gradual loss of ADAM3 and ADAM6 proteins during epididymal transit. In the distal epididymis, these spermatozoa appear to lack calcium-dependent associations with the immobilizing glutinous extracellular material and are released as single, vigorously motile cells that display no tendency for head-to-head agglutination and lack affinity to the oviductal epithelium. In sperm-egg binding assay, they are unable to establish a tenacious association with the zona pellucida, yet they are capable of fertilization. Furthermore, these sperm show accelerated capacitation resulting in an overall in vitro fertilizing ability superior to that of wild-type sperm. We conclude that the physiological role of sperm adhesiveness is in the mechanism of restricted sperm entry into the oviduct rather than in sperm-egg interaction.
authors: Department of Surgery and Cancer, Imperial College London, Hammersmith Campus, Du Cane Rd., London, W12 0NN, UK.
authors: Anton
authors: A
authors: Krutskikh
authors: Ariel
authors: A
authors: Poliandri
authors: Victoria
authors: V
authors: Cabrera-Sharp
authors: Jean Louis
authors: JL
authors: Dacheux
authors: Matti
authors: M
authors: Poutanen
authors: Ilpo
authors: I
authors: Huhtaniemi
mesh_terms: D051722:ADAM Proteins / Q000235:genetics / Q000378:metabolism; D000818:Animals; D004722:Endoribonucleases / Q000235:genetics / Q000378:metabolism*; D004822:Epididymis / Q000201:enzymology* / Q000378:metabolism; D005260:Female; D005298:Fertility / Q000235:genetics / Q000502:physiology*; D005307:Fertilization in Vitro; D015151:Immunoblotting; D008297:Male; D008562:Membrane Glycoproteins / Q000235:genetics / Q000378:metabolism; D051379:Mice; D008810:Mice, Inbred C57BL; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013079:Sperm Maturation / Q000235:genetics / Q000502:physiology; D013084:Sperm-Ovum Interactions / Q000235:genetics / Q000502:physiology; D013094:Spermatozoa / Q000378:metabolism; D015044:Zona Pellucida / Q000378:metabolism
chemical_list: D008562:Membrane Glycoproteins; D004722:Endoribonucleases; D051722:ADAM Proteins; C485429:Adam3 protein, mouse