title: The mouse complement regulator CD59b is significantly expressed only in testis and plays roles in sperm acrosome activation and motility.
abstract: In mouse, genes encoding complement regulators CD55 and CD59 have been duplicated. The first described form of CD59, CD59a, is broadly distributed in mouse tissues, while the later identified CD59b was originally described as testis specific. Subsequent studies have been contradictory, some reporting widespread and abundant expression of CD59b. Resolution of the distribution patterns of the CD59 isoforms is important for interpretation of disease studies utilising CD59 knockout mice. Here we have performed a comprehensive distribution study of the CD59 isoforms at the mRNA and protein levels. These data confirm that expression of CD59b is essentially restricted to adult testis; trace expression in other tissues is a consequence of contamination with blood cells, shown previously to express CD59b at low level. In testis, onset of expression of CD59b coincided with puberty and was predominant on the spermatozoal acrosome. Ligation of CD59b, but not CD59a, markedly reduced spermatozoal motility, suggesting a specific role in reproductive function.
authors.affiliation: Department of Medical Biochemistry and Immunology, School of Medicine, Cardiff University, Cardiff CF14 4XN, UK. donevrm@cardiff.ac.uk
authors.forename: Rossen M
authors.initials: RM
authors.lastname: Donev
authors.forename: Baalasubramanian
authors.initials: B
authors.lastname: Sivasankar
authors.forename: Masashi
authors.initials: M
authors.lastname: Mizuno
authors.forename: B Paul
authors.initials: BP
authors.lastname: Morgan
mesh_terms: D020101:Acrosome Reaction / Q000502:physiology*; D000818:Animals; D000911:Antibodies, Monoclonal; D018957:CD59 Antigens / Q000235:genetics* / Q000378:metabolism*; D003165:Complement System Proteins / Q000235:genetics* / Q000378:metabolism*; D020869:Gene Expression Profiling; D018507:Gene Expression Regulation, Developmental; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D009928:Organ Specificity; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D012741:Sexual Maturation; D013081:Sperm Motility / Q000502:physiology*; D013737:Testis / Q000166:cytology / Q000378:metabolism*
chemical_list: D000911:Antibodies, Monoclonal; D018957:CD59 Antigens; D012333:RNA, Messenger; D003165:Complement System Proteins