Siva Kumar, A.V.N(MAJOR)Rambabu Naik, BPunya Kumari, BSRAVANI PRAGNA, K2018-12-012018-12-012017-05http://krishikosh.egranth.ac.in/handle/1/5810085010THESESABSTRACT : The expression of Leptin receptor (LepR) mRNA and protein was studied in sheep using Real time quantitative PCR and Immunohistochemistry in the cumulus cells and oocytes from : (i) In vivo grown preantral, early antral, antral, large antral follicles and Cumulus Oocyte Complexes (COCs) obtained from large antral follicles and subjected to 24h of In Vitro Maturation ( IVM) and (ii) Preantral follicles (PFs’) exposed to TCM199B, TCM199BL (10ng/mL) and TCM199BHGL (10ng/mL) media for 3min, cultured in vitro for two, four or six days and subsequently matured in vitro for 24h in respective cultures separately. LepR was observed at all stages of in vivo grown and in vitro cultured ovarian follicles in both cumulus cells and oocytes. Expression levels and patterns of LepR mRNA in PFs’ cultured in TCM199BHGL was similar to in vivo in all the stages except in cumulus cells from COCs after in vitro maturation for 24h, where the expression was significantly higher which was a positive effect. The expression of LepR in cumulus cells among the three different in vitro culturing conditions was significantly higher in PFs’ cultured in TCM199BHGL medium. In the oocytes, the Leptin receptor expression was similar or significantly higher in PFs’ cultured in TCM199BHGL medium than in vivo grown follicles except in PFs’ exposed to 3min stage which could suggest the synergistic action of growth factors and hormones with Leptin. Immunohistochemistry studies revealed highest intensity of Leptin receptor protein expression in the oocytes. Mild to moderate staining was observed in cumulus cells with good intensity in large antral stages. This protein expression coincided with gene expression. From our studies it is concluded that Leptin along with other growth factors and hormones supplementation stimulated the expression of Leptin receptor mRNA and protein on par with that of in vivo /even higher than that of in vivo condition.ennullThesis