Dynamic testicular adhesion junctions are immunologically unique. II. Localization of classic cadherins in rat testis.
In the seminiferous epithelium, morphologically diverse junctions mediate inter-Sertoli and Sertoli-germ cell adhesive contact and likely transmit signals between contacting cells. Defining the molecular composition of testicular cell-cell junctions is an important step in determining their function. Proteins belonging to the cadherin superfamily are important mediators of cell-cell adhesion, as well as cell signaling. Here, we determined the spatial and temporal protein expression of four classic cadherins in rat testis: N-cadherin, cadherin-6, cadherin-11, and a cadherin defined by an antiserum generated against a conserved classic cadherin peptide (L4). Through Western blot analysis, all antibodies recognized unique proteins. Similarly, each cadherin displayed unique, cell-type specific immunostaining patterns. Whereas N-cadherin, cadherin-11, and L4-positive cadherin were expressed from Postnatal Day 7 through adulthood, cadherin-6 protein was not present at Postnatal Day 7 and first appeared at Day 21. Immunostaining of testis cryosections on Postnatal Days 7, 21, 31, 43, and those of adults indicated that cadherin-11 localized to peritubular cell junctions. N-cadherin immunostaining localized to basal inter-Sertoli junctions, Sertoli-spermatocyte junctions, and at about stages I-VII in Sertoli-elongate spermatid junctions. Cadherin-6 immunostaining was restricted to Sertoli-round spermatid and in Sertoli-elongate spermatid junctions at approximately stages XII-I. Finally, L4-positive immunostaining also detected Sertoli-round spermatid junctions in addition to Sertoli-elongate spermatid junctions at approximately stages XII-I. These data show that the various testicular cell-cell junctions are molecularly unique and dynamic complexes.
Johnson
Kamin J
KJ
Department of Pathology and Laboratory Medicine, Brown University, 175 Meeting Street, Providence, Rhode Island 02912, USA. kamin_johnson@brown.edu
Boekelheide
Kim
K
D000818:Animals; D000911:Antibodies, Monoclonal; D015153:Blotting, Western; D015820:Cadherins / Q000032:analysis*; D002448:Cell Adhesion; D007365:Intercellular Junctions / Q000737:chemistry*; D008297:Male; D010446:Peptide Fragments / Q000032:analysis; D051381:Rats; D011916:Rats, Inbred F344; D012708:Sertoli Cells / Q000648:ultrastructure; D013087:Spermatids / Q000648:ultrastructure; D013737:Testis / Q000737:chemistry / Q000254:growth & development / Q000648:ultrastructure*
D000911:Antibodies, Monoclonal; D015820:Cadherins; D010446:Peptide Fragments; C086960:osteoblast cadherin; C087310:K cadherin