title: Immunohistochemical demonstration of cytoskeletal proteins in the testis of the Japanese black bear, Ursus thibetanus japonicus.
abstract: The seasonal changes of the cytoskeletal protein expressions were immunohistochemically investigated in the testes of Japanese black bear, Ursus thibetanus japonicus. A strong immunoreaction for alpha-smooth muscle actin is restricted to the vascular smooth muscle cells and the peritubular cells which surround the seminiferous tubules by several layers throughout the year. Weak immunoreactions for B4 antigen and desmin were observed in the vascular smooth muscle cells and in a part of peritubular cells throughout the year. A strong immunoreaction for vimentin was also detected in the fibroblasts and Leydig cells, in addition to the vascular smooth muscle and epithelial cells and the peritubular cells throughout the year. A strong alpha-tubulin immunoreaction was detected in the elongating spermatids during the acrosome phase of spermiogenesis in May and June. The cytoplasm of several Sertoli cells was faintly immunoreacted for vimentin in the basal and lateral region, while an intense alpha-tubulin reaction was seen in the entire cytoplasm in May, April and June. In November, January and March, the immunoreactions for vimentin and alpha-tubulin strongly accumulate in a perinuclear region of Sertoli cells when developmental spermatids are not seen in the seminiferous tubules. These accumulations in the immunoreactions for vimentin and alpha-tubulin seem to be caused by the reduction in size of Sertoli cells cytoplasm with season. However, the seasonal changes of distributions in the cytoskeletal proteins are obscure in the bear testes. These results suggest that the contents of cytoskeletal proteins may not change in relation to the morphological differences with season in the testes of the seasonal breeders.
authors.affiliation: Laboratory of Veterinary Anatomy, Faculty of Agriculture, Gifu University, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Komatsu
authors.forename: Y
authors.initials: Y
authors.lastname: Yamamoto
authors.forename: Y
authors.initials: Y
authors.lastname: Atoji
authors.forename: T
authors.initials: T
authors.lastname: Tsubota
authors.forename: Y
authors.initials: Y
authors.lastname: Suzuki
mesh_terms: D000199:Actins / Q000032:analysis; D000818:Animals; D001143:Arousal; D003598:Cytoskeletal Proteins / Q000032:analysis*; D006605:Hibernation; D007150:Immunohistochemistry; D008297:Male; D009131:Muscle, Smooth, Vascular / Q000166:cytology; D012621:Seasons; D012671:Seminiferous Tubules / Q000098:blood supply / Q000166:cytology; D013737:Testis / Q000098:blood supply / Q000166:cytology* / Q000502:physiology; D001503:Ursidae / Q000033:anatomy & histology* / Q000502:physiology
chemical_list: D000199:Actins; D003598:Cytoskeletal Proteins