Expression and functional characterization of the adhesion molecule spermatogenic immunoglobulin superfamily in the mouse testis.
ABSTRACT Spermatogenic immunoglobulin superfamily (SgIGSF) is a mouse protein belonging to the immunoglobulin superfamily expressed in the spermatogenic cells of seminiferous tubules. We produced a specific polyclonal antibody against SgIGSF. Western blot analysis of the testes from postnatal developing mice using this antibody demonstrated multiple immunopositive bands of 80-130 kDa, which increased in number and size with the postnatal age. Enzymatic N-glycolysis caused reduction in the size of these bands to 70 kDa, indicating that SgIGSF is a glycoprotein and its glycosylation pattern and extent are developmentally regulated. Immunohistochemical analysis of the adult testis demonstrated that SgIGSF was present in the spermatogenic cells in the earlier steps of spermatogenesis and increased in amount from intermediate spermatogonia through zygotene spermatocytes but was diminished in the steps from early pachytene spermatocytes through round spermatids. After meiosis, SgIGSF reappeared in step 7 spermatids and was present in the elongating spermatids until spermiation. The immunoreactivity was localized primarily on the cell membrane. Consistent with the findings in adult testes, the analysis of the developing testes revealed that SgIGSF was expressed separately in the spermatogenic cells in earlier and later phases. Sertoli cells had no expression of SgIGSF, whereas both SgIGSF immunoprecipitated from the testis lysate and produced in COS-7 cells was shown to bind to the surface of Sertoli cells in primary culture. These results suggested that SgIGSF on the surface of spermatogenic cells binds to some membrane molecules on Sertoli cells in a heterophilic manner and thereby may play diverse roles in the spermatogenesis.
Article: Expression of the Adhesion Molecule Spermatogenic Immunoglobulin Superfamily (SgIGSF) in Mouse Tissues.[show abstract] [hide abstract]
ABSTRACT: Spermatogenic immunoglobulin superfamily (SgIGSF) is an adhesion molecule originally isolated from adult mouse testis. In the testis, SgIGSF is expressed specifically in spermatogenic cells and may be involved in spermatogenesis. SgIGSF may also be involved in synapse formation and tumor suppression. In the present study, we examined the expression and cellular localization of SgIGSF in the entire adult mouse organs and tissues using Western blot analysis and immunohistochemistry at light and electron microscopic levels. Western blot analysis revealed that SgIGSF is expressed not only in the testis but also in the liver, lung, and nervous system including the cerebrum, cerebellum and sciatic nerve. The nervous system as well as testis showed multiple immunoreactive bands ranging from 45 to 100 kDa, whereas the liver and lung showed a single 100 kDa band. Immunohistochemisfry demonstrated that in the nervous system, SgIGSF is localized to the membranes of synapses, axons and Schwann cells. In contrast, in the lung and liver SgIGSF was localized to the membranes of apposing respiratory epithelial cells, hepatocytes and biliary epithelial cells. These results suggested that SgIGSF plays multiple physiological roles in the adult mouse as an adhesion molecule.
Article: Expression and localization of the cell adhesion molecule SgIGSF during regeneration of the olfactory epithelium in mice.[show abstract] [hide abstract]
ABSTRACT: Spermatogenic immunoglobulin superfamily (SgIGSF) is a cell adhesion molecule originally discovered in mouse testis. SgIGSF is expressed not only in spermatogenic cells but also in lung and liver epithelial cells and in neurons and glia of the central and peripheral nervous systems. In the present study, we examined the expression and localization of SgIGSF in mouse olfactory epithelium before and after transection of the olfactory nerves, by RT-PCR, Western blotting and immunohistochemistry. In normal olfactory mucosa, SgIGSF showed 100 kDa in molecular weight, which was identical with that in the lung but different from that in the brain. SgIGSF was expressed on the membrane of all olfactory, sustentacular and basal cells, but more abundantly in the apical portions of the olfactory epithelium where the dendrites of olfactory cells are in contact with sustentacular cells. After olfactory nerve transection, mature olfactory cells disappeared in 4 days but were regenerated around 7-15 days by proliferation and differentiation of basal cells into mature olfactory cells through the step of immature olfactory cells. During this period, both the mRNA and protein for SgIGSF showed a transient increase, with peak levels at 7 days and 11 days, respectively, after the transection. Immunohistochemistry showed that the enriched immunoreactivity for SgIGSF at 7-11 days was localized primarily to the membrane of immature olfactory cells. These results suggested that, during regeneration of the olfactory epithelium, the adhesion molecule SgIGSF plays physiological roles in differentiation, migration, and maturation of immature olfactory cells.Acta histochemica et cytochemica official journal of the Japan Society of Histochemistry and Cytochemistry 06/2007; 40(2):43-52. · 1.11 Impact Factor
Article: Disruption of spermatogenic cell adhesion and male infertility in mice lacking TSLC1/IGSF4, an immunoglobulin superfamily cell adhesion molecule.[show abstract] [hide abstract]
ABSTRACT: TSLC1/IGSF4, an immunoglobulin superfamily molecule, is predominantly expressed in the brain, lungs, and testes and plays important roles in epithelial cell adhesion, cancer invasion, and synapse formation. We generated Tslc1/Igsf4-deficient mice by disrupting exon 1 of the gene and found that Tslc1(-/-) mice were born with the expected Mendelian ratio but that Tslc1(-/-) male mice were infertile. In 11-week-old adult Tslc1(-/-) mice, the weight of a testis was 88% that in Tslc1(+/+) mice, and the number of sperm in the semen was approximately 0.01% that in Tslc1(+/+) mice. Histological analysis revealed that the round spermatids and the pachytene spermatocytes failed to attach to the Sertoli cells in the seminiferous tubules and sloughed off into the lumen with apoptosis in the Tslc1(-/-) mice. On the other hand, the spermatogonia and the interstitial cells, including Leydig cells, were essentially unaffected. In the Tslc1(+/+) mice, TSLC1/IGSF4 expression was observed in the spermatogenic cells from the intermediate spermatogonia to the early pachytene spermatocytes and from spermatids at step 7 or later. These findings suggest that TSLC1/IGSF4 expression is indispensable for the adhesion of spermatocytes and spermatids to Sertoli cells and for their normal differentiation into mature spermatozoa.Molecular and Cellular Biology 06/2006; 26(9):3610-24. · 5.53 Impact Factor