title: Oligo-astheno-teratozoospermia in mice lacking RA175/TSLC1/SynCAM/IGSF4A, a cell adhesion molecule in the immunoglobulin superfamily.
abstract: RA175/TSLC1/SynCAM/IGSF4A (RA175), a member of the immunoglobulin superfamily with Ca2+-independent homophilic trans-cell adhesion activity, participates in synaptic and epithelial cell junctions. To clarify the biological function of RA175, we disrupted the mouse Igsf4a (Ra175/Tslc1/SynCam/Igsf4a Ra175) gene. Male mice lacking both alleles of Ra175 (Ra175-/-) were infertile and showed oligo-astheno-teratozoospermia; almost no mature motile spermatozoa were found in the epididymis. Heterozygous males and females and homozygous null females were fertile and had no overt developmental defects. RA175 was mainly expressed on the cell junction of spermatocytes, elongating and elongated spermatids (steps 9 to 15) in wild-type testes; the RA175 expression was restricted to the distal site (tail side) but not to the proximal site (head side) in elongated spermatids. In Ra175-/- testes, elongated and mature spermatids (steps 13 to 16) were almost undetectable; round spermatids were morphologically normal, but elongating spermatids (steps 9 to 12) failed to mature further and to translocate to the adluminal surface. The remaining elongating spermatids at improper positions were finally phagocytosed by Sertoli cells. Furthermore, undifferentiated and abnormal spermatids exfoliated into the tubular lumen from adluminal surfaces. Thus, RA175-based cell junction is necessary for retaining elongating spermatids in the invagination of Sertoli cells for their maturation and translocation to the adluminal surface for timely release.
authors.affiliation: Division of Differentiation and Development, Department of Inherited Metabolic Disorder, National Institute of Neuroscience, NCNP, Ogawahigashi-machi 4-1-1, Kodaira, Tokyo 187-8502, Japan.
authors.forename: Eriko
authors.initials: E
authors.lastname: Fujita
authors.forename: Yoriko
authors.initials: Y
authors.lastname: Kouroku
authors.forename: Satomi
authors.initials: S
authors.lastname: Ozeki
authors.forename: Yuko
authors.initials: Y
authors.lastname: Tanabe
authors.forename: Yoshiro
authors.initials: Y
authors.lastname: Toyama
authors.forename: Mamiko
authors.initials: M
authors.lastname: Maekawa
authors.forename: Naosuke
authors.initials: N
authors.lastname: Kojima
authors.forename: Haruki
authors.initials: H
authors.lastname: Senoo
authors.forename: Kiyotaka
authors.initials: K
authors.lastname: Toshimori
authors.forename: Takashi
authors.initials: T
authors.lastname: Momoi
mesh_terms: D000818:Animals; D000075982:Cell Adhesion Molecule-1; D015815:Cell Adhesion Molecules / Q000235:genetics / Q000378:metabolism*; D004622:Embryo, Mammalian / Q000378:metabolism; D004822:Epididymis / Q000166:cytology / Q000378:metabolism; D005260:Female; D007136:Immunoglobulins / Q000235:genetics / Q000378:metabolism*; D007365:Intercellular Junctions / Q000378:metabolism; D008297:Male; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism*; D051379:Mice; D046529:Microscopy, Electron, Transmission; D009845:Oligospermia / Q000235:genetics / Q000473:pathology*; D010587:Phagocytosis / Q000235:genetics / Q000502:physiology; D012708:Sertoli Cells / Q000502:physiology / Q000648:ultrastructure; D013087:Spermatids / Q000502:physiology / Q000648:ultrastructure; D013091:Spermatogenesis / Q000235:genetics / Q000502:physiology*; D013094:Spermatozoa / Q000502:physiology* / Q000648:ultrastructure; D013737:Testis / Q000378:metabolism* / Q000648:ultrastructure; D025521:Tumor Suppressor Proteins / Q000235:genetics / Q000378:metabolism*
chemical_list: C498598:Cadm1 protein, mouse; D000075982:Cell Adhesion Molecule-1; D015815:Cell Adhesion Molecules; D007136:Immunoglobulins; D008565:Membrane Proteins; D025521:Tumor Suppressor Proteins