title: JAM-A is present in mammalian spermatozoa where it is essential for normal motility.
abstract: Junctional adhesion molecules (JAMs) that are expressed in endothelial and epithelial cells and function in tight junction assembly, also perform important roles in testis where the closely-related JAM-A, JAM-B, and JAM-C are found. Disruption of murine Jam-B and Jam-C has varying effects on sperm development and function; however, deletion of Jam-A has not yet been studied. Here we show for the first time that in addition to expression in the Sertoli-Sertoli tight junctions in the seminiferous tubules, the approximately 32 kDa murine JAM-A is present in elongated spermatids and in the plasma membrane of the head and flagellum of sperm. Deletion of Jam-A, using the gene trap technology, results in flagellar defects at the ultrastructural level. In Jam-A-deficient mice, which have reduced litter size, both progressive and hyperactive motility are significantly affected (P<0.0001) before and, more severely, after capacitation. The findings show that JAM-A is involved in sperm tail formation and is essential for normal motility, which may occur via its signal transduction and protein phosphorylation properties. Detection of JAM-A in human sperm proteins indicates that its role may be conserved in sperm motility and that JAM-A may be a candidate gene for the analysis of idiopathic sperm motility defects resulting in male subfertility in the human population.
authors.affiliation: Department of Biological Sciences, 219 McKinly Lab, University of Delaware, Newark, DE 19716, USA.
authors.forename: Minghai
authors.initials: M
authors.lastname: Shao
authors.forename: Ananya
authors.initials: A
authors.lastname: Ghosh
authors.forename: Vesselina G
authors.initials: VG
authors.lastname: Cooke
authors.forename: Ulhas P
authors.initials: UP
authors.lastname: Naik
authors.forename: Patricia A
authors.initials: PA
authors.lastname: Martin-DeLeon
mesh_terms: D000818:Animals; D015815:Cell Adhesion Molecules / Q000032:analysis / Q000502:physiology*; D004822:Epididymis / Q000502:physiology; D006801:Humans; D007136:Immunoglobulins / Q000032:analysis / Q000502:physiology*; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D011956:Receptors, Cell Surface / Q000032:analysis / Q000502:physiology*; D013081:Sperm Motility; D013094:Spermatozoa / Q000737:chemistry*
chemical_list: D015815:Cell Adhesion Molecules; C407243:F11R protein, human; C498686:F11r protein, mouse; D007136:Immunoglobulins; D011956:Receptors, Cell Surface