title: Biological properties of Indian walking catfish (Clarias batrachus) (L.) gonadotropins in female reproduction.
abstract: The biological activities of catfish LH-like (semi-purified: s200a and purified Qa) and FSH-like (semi-purified: s200b and purified: Qb) were compared in intact and hypophysectomized female catfish, Clarias batrachus, during preparatory and the pre-spawning periods on vitellogenesis and ovarian maintenance, as well as in vitro final maturation of oocytes, germinal vesicle breakdown (GVBD). During preparatory period, in intact catfish, semi-purified FSH-like induced complete vitellogenesis through the production of estradiol-17β (E2) and vitellogenin (Vg) accompanied by the formation of SIII yolky oocytes. On the other hand, semi-purified LH-like had induced the formation of only SII (characterized by the appearance of cortical alveoli in cytoplasm) oocytes, which indicates the initiation of vitellogenesis. In hypophysectomized female catfish, purified LH-like but not FSH-like induced the formation of SII oocytes in the ovaries. Treatment with semi-purified LH- and FSH-like at the dose level of 5 µg/fish/day for 7 days significantly maintained the yolky oocytes in gravid catfish after hypophysectomy with a significant reduction in plasma Vg, but not E2 levels, indicating some unknown GtH-induced factor doing the job. In in vitro oocytes culture, both LH- and FSH-like induced GVBD, but the response was significantly more with LH-like than FSH-like. All these findings revealed that both LH-like and FSH-like have overlapping physiological functions, but their responses differ depending on the physiological status of the catfish.
authors.affiliation: Department of Zoology, Visva-Bharati University, Santiniketan, 731235, West Bengal, India.
authors.forename: Shrabanti
authors.initials: S
authors.lastname: Sarkar
authors.forename: Debapriya
authors.initials: D
authors.lastname: Bhattacharya
authors.forename: Subir Kumar
authors.initials: SK
authors.lastname: Juin
authors.forename: Panchanan
authors.initials: P
authors.lastname: Nath
mesh_terms: D000818:Animals; D002397:Catfishes / Q000502:physiology*; D004958:Estradiol / Q000097:blood / Q000378:metabolism; D005260:Female; D006062:Gonadotropins / Q000235:genetics / Q000378:metabolism*; D007016:Hypophysectomy; D059471:In Vitro Oocyte Maturation Techniques; D009865:Oocytes / Q000502:physiology; D010053:Ovary / Q000166:cytology / Q000378:metabolism; D012098:Reproduction / Q000502:physiology*; D014818:Vitellogenesis / Q000502:physiology; D014819:Vitellogenins / Q000097:blood / Q000378:metabolism
chemical_list: D006062:Gonadotropins; D014819:Vitellogenins; D004958:Estradiol