title: Localization of IGF proteins in various stages of ovarian follicular development and modulatory role of IGF-I on granulosa cell steroid production in water buffalo (Bubalus bubalis).
abstract: The present study aimed to determine the expression of insulin like growth factor (IGF) genes in the bubaline ovarian follicles and modulatory role of IGF-I on progesterone production from granulosa cells (GC) of pre-ovulatory follicle in vitro. According to size, follicles were classified into four groups: GI (small), GII (medium), GIII (large) and GIV (preovulatory). All IGF genes were expressed in both GC and theca interna (TI) cells. The relative expression of IGF-I and IGF receptor I (IGFR-I) genes increased with follicle size and was greatest in the pre-ovulatory follicle (P<0.05). Expression of IGF-II and IGFR-II genes was minimal in GC but was readily detected in TI cells. In TI cells, the gene expression was greater in medium and large as compared to small and pre-ovulatory follicles. The expression of all binding protein (IGFBP) genes was detected in both GC and TI cells. Expression of IGFBP-3 gene increased with follicle size and was greatest in pre-ovulatory follicles (P<0.05). The expression of IGFBP-2 and IGFBP-4 was less in pre-ovulatory follicles but expression of IGFBP-5 and IGFBP-6 genes were greater at this stage. The GC culture was conducted for three time durations and with three doses of IGF-I. Expression of steroidogenic genes (StAR, CYP11A1, HSD3B) and progesterone concentration were increased in a dose and time dependent fashion. The present study, therefore, provided evidence of an autocrine/paracrine role of IGFs in follicular development and a stimulatory role of IGF1 in steroid production in GC of preovulatory follicles in the bubaline species.
authors.affiliation: Physiology & Climatology, Indian Veterinary Research Institute, Izatnagar, Bareilly, Uttar Pradesh 243122, India.
authors.forename: Jai
authors.initials: J
authors.lastname: Singh
authors.affiliation: Physiology & Climatology, Indian Veterinary Research Institute, Izatnagar, Bareilly, Uttar Pradesh 243122, India.
authors.forename: A
authors.initials: A
authors.lastname: Paul
authors.affiliation: Physiology & Climatology, Indian Veterinary Research Institute, Izatnagar, Bareilly, Uttar Pradesh 243122, India.
authors.forename: N
authors.initials: N
authors.lastname: Thakur
authors.affiliation: Physiology & Climatology, Indian Veterinary Research Institute, Izatnagar, Bareilly, Uttar Pradesh 243122, India.
authors.forename: V P
authors.initials: VP
authors.lastname: Yadav
authors.affiliation: Physiology & Climatology, Indian Veterinary Research Institute, Izatnagar, Bareilly, Uttar Pradesh 243122, India.
authors.forename: R P
authors.initials: RP
authors.lastname: Panda
authors.affiliation: Biochemistry Section, Indian Veterinary Research Institute, Izatnagar, Bareilly, Uttar Pradesh 243122, India.
authors.forename: S K
authors.initials: SK
authors.lastname: Bhure
authors.affiliation: Physiology & Climatology, Indian Veterinary Research Institute, Izatnagar, Bareilly, Uttar Pradesh 243122, India. Electronic address: msarkar24@gmail.com.
authors.forename: M
authors.initials: M
authors.lastname: Sarkar
mesh_terms: D000818:Animals; D002020:Buffaloes / Q000502:physiology*; D005260:Female; D005786:Gene Expression Regulation / Q000502:physiology*; D006107:Granulosa Cells / Q000378:metabolism*; D018969:Insulin-Like Growth Factor Binding Proteins / Q000235:genetics / Q000378:metabolism; D007334:Insulin-Like Growth Factor I / Q000235:genetics / Q000378:metabolism*; D006080:Ovarian Follicle / Q000378:metabolism*; D011374:Progesterone / Q000235:genetics / Q000378:metabolism*; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism
chemical_list: D018969:Insulin-Like Growth Factor Binding Proteins; D012333:RNA, Messenger; D011374:Progesterone; D007334:Insulin-Like Growth Factor I
keywords: Buffalo; Growth factor; IGF; IGFBP; Ovarian follicle