title: Post-testicular sperm maturation and identification of an epididymal protein in the Japanese quail (Coturnix coturnix japonica).
abstract: The role of the avian epididymis in post-testicular development and capacitation was examined to assess whether avian spermatozoa undergo any processes similar to those characteristic of mammalian sperm development. We found no evidence of a need for quail sperm to undergo capacitation and 90% of testicular sperm could bind to a perivitelline membrane and acrosome react. However, computer-assisted sperm analysis showed that 20% of testicular sperm from the quail were capable of movement and only about 12% of the motile sperm would have a curvilinear velocity greater than the mean for sperm from the distal epididymis. Nevertheless, epididymal transit was associated with increases in mean sperm velocity and the proportion of motile sperm. Together, these findings explain why earlier workers have achieved some fertilizations following inseminations of testicular spermatozoa and also demonstrate the need for some epididymal maturation of avian spermatozoa. Analysis of the electrophoretic profile of quail epididymal luminal proteins revealed that only one major protein (∼16 kDa) is secreted by the epididymis and it was virtually the only protein secreted by the ipsilateral epididymis following unilateral orchidectomy. Mass spectrometry showed that this protein is hemoglobin; this finding was confirmed using anti-hemoglobin antibodies. It is suggested that hemoglobin may support sperm metabolism in the quail epididymis, aid in motility, and/or serve as an antioxidant.
authors.affiliation: Reproductive Science Group, Discipline of Biological Sciences, School of Environmental and Life Sciences, University of Newcastle, University Drive, Callaghan, New South Wales 2308, Australia.
authors.forename: Brett
authors.initials: B
authors.lastname: Nixon
authors.forename: Katherine A
authors.initials: KA
authors.lastname: Ewen
authors.forename: Klara M
authors.initials: KM
authors.lastname: Krivanek
authors.forename: John
authors.initials: J
authors.lastname: Clulow
authors.forename: Grahame
authors.initials: G
authors.lastname: Kidd
authors.forename: Heath
authors.initials: H
authors.lastname: Ecroyd
authors.forename: Russell C
authors.initials: RC
authors.lastname: Jones
mesh_terms: D000177:Acrosome / Q000378:metabolism; D000818:Animals; D003370:Coturnix / Q000502:physiology; D030501:Epididymal Secretory Proteins / Q000302:isolation & purification* / Q000378:metabolism; D004822:Epididymis / Q000737:chemistry / Q000378:metabolism; D008297:Male; D051379:Mice; D013075:Sperm Capacitation; D013079:Sperm Maturation / Q000502:physiology*; D013081:Sperm Motility; D013094:Spermatozoa / Q000378:metabolism; D013737:Testis / Q000166:cytology
chemical_list: D030501:Epididymal Secretory Proteins