title: Tracing sperm acrosome differentiation in the testis and maturation in the epididymis of the tammar wallaby (Macropus eugenii) with a 45-kDa acrosome-membrane-associated protein.
abstract: A 45-kDa protein was originally extracted from a depression, where the acrosome is lodged, on the anterior end of the sperm nucleus of ejaculated wallaby spermatozoa. Using immunofluorescent and confocal microscopes, this study demonstrates that the 45-kDa protein is persistently localized to the sperm acrosome throughout the periods of spermiogenesis, spermiation, epididymal maturation and ejaculation in the tammar wallaby. The distribution of the 45-kDa protein is always on the perimeter of the acrosome and associated with the acrosomal membrane, so that changes in the shape of the 45-kDa immunofluorescent labelling mirror changes in the shape of the acrosome during its differentiation in the testis and epididymis. Thus, the 45-kDa protein may be used as a molecular marker to study the marsupial acrosome differentiation and to chart the events of testicular and epididymal maturation of the spermatozoa. Furthermore, the behaviour of the 45-kDa protein during the immunostaining process suggests that this protein is a largely insoluble and detergent-resistant protein and may play an important role in attachment of the acrosome to the nucleus during sperm formation, similar to those inner acrosomal-membrane-associated proteins that have been reported in eutherian spermatozoa.
authors.affiliation: Cooperative Research Centre for the Conservation and Management of Marsupials, The University of Newcastle, NSW, Australia.
authors.forename: Xiyi
authors.initials: X
authors.lastname: Zhang
authors.forename: Minjie
authors.initials: M
authors.lastname: Lin
mesh_terms: D000177:Acrosome / Q000737:chemistry*; D000818:Animals; D000918:Antibody Specificity; D015415:Biomarkers; D002454:Cell Differentiation; D004542:Ejaculation; D004822:Epididymis / Q000166:cytology* / Q000502:physiology; D005260:Female; D005455:Fluorescent Antibody Technique; D007614:Macropodidae / Q000254:growth & development*; D008297:Male; D011506:Proteins / Q000737:chemistry / Q000378:metabolism; D013094:Spermatozoa / Q000378:metabolism; D013737:Testis / Q000166:cytology* / Q000254:growth & development*
chemical_list: D015415:Biomarkers; D011506:Proteins