title: Expression of growth differentiation factor 9 (GDF9) and its receptor in adult cat testis.
abstract: Oocyte-secreted growth differentiation factor (GDF) 9 plays an essential role during follicle maturation through actions on granulosa cells. Despite its critical role in female reproduction, GDF9 expression, signalling and function are less well characterized during spermatogenesis. The purpose of this study was to investigate temporal and spatial expression and potential cellular targets of GDF9 in the adult cat testis. Our result confirmed that GDF9 is stage-specifically localized in the cytoplasm of round spermatids and pachytene spermatocytes of the cat seminiferous epithelium. In particular, activin receptor-like kinase (ALK) 5, the type I receptor of GDF9, is principally localized in the cytoplasm of round spermatids. Smad2/3, signal transducers for GDF9 signalling pathway, is mainly immunolocalized in the cytoplasm of germ cells, Sertoli cells and Leydig cells, but the expression in germ cells are weaker than in Sertoli cells. The expression pattern of ALK5 and Smad2/3 show that GDF9-ALK5-Smad2/3 may not be the only signalling pathway for testicular cell to respond to GDF9. Overall, our results demonstrate that GDF9 is a germ cell-specific factor in the adult cat testis, and that GDF9 regulates the tight junctions of Sertoli cells by paracrine secretion, and regulates the germ cells by autocrine secretion.
authors.affiliation: Institute of Animal Biotechnology, College of Animal Science and Technology, Shanxi Agricultural University, Taigu, Shanxi, PR China.
authors.forename: Li
authors.initials: L
authors.lastname: Zhao
authors.forename: JunPing
authors.initials: J
authors.lastname: He
authors.forename: QingYun
authors.initials: Q
authors.lastname: Guo
authors.forename: XueXue
authors.initials: X
authors.lastname: Wen
authors.forename: XueJing
authors.initials: X
authors.lastname: Zhang
authors.forename: ChangSheng
authors.initials: C
authors.lastname: Dong
mesh_terms: D000818:Animals; D019898:Autocrine Communication; D052004:Bone Morphogenetic Protein Receptors / Q000378:metabolism*; D002415:Cats; D055429:Growth Differentiation Factor 9 / Q000096:biosynthesis*; D007150:Immunohistochemistry; D008297:Male; D019899:Paracrine Communication; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism; D000077293:Receptor, Transforming Growth Factor-beta Type I; D018125:Receptors, Transforming Growth Factor beta / Q000378:metabolism; D012708:Sertoli Cells / Q000378:metabolism / Q000648:ultrastructure; D015398:Signal Transduction; D051899:Smad2 Protein / Q000378:metabolism; D051900:Smad3 Protein / Q000378:metabolism; D013091:Spermatogenesis / Q000502:physiology; D013737:Testis / Q000502:physiology* / Q000648:ultrastructure; D019108:Tight Junctions / Q000378:metabolism
chemical_list: D055429:Growth Differentiation Factor 9; D018125:Receptors, Transforming Growth Factor beta; D051899:Smad2 Protein; D051900:Smad3 Protein; D017346:Protein Serine-Threonine Kinases; D052004:Bone Morphogenetic Protein Receptors; D000077293:Receptor, Transforming Growth Factor-beta Type I