Please use this identifier to cite or link to this item: http://krishikosh.egranth.ac.in/handle/1/93695
Authors: SURABHI KESHARWANI
Title: EFFECT OF LEPTIN IN IN VITRO MATURATION OF SHEEP OOCYTES
Publisher: PVNR TVU
Type: Thesis
Series/Report no.: D;434
Agrotags: EFFECT OF LEPTIN IN IN VITRO MATURATION OF SHEEP OOCYTES
Abstract: Leptin has beneficial effects on mammalian oocyte maturation, development and enhances the transcription levels of developmentally important genes. For the present study total of 1520 sheep ovaries were collected from slaughter house during the breeding and non-breeding season. From those ovaries 3241 oocytes were retrieved by different isolation methods. Four experiments were conducted to study the factors affecting in vitro maturation of sheep oocytes. In Experiment- 1, Efficacy of oocyte retrieval methods in relation to oocyte quality and quantity were studied. A total 3241 oocytes were retrieved by three methods Name of the Author : SURABHI KESHARWANI Title of the Thesis : “EFFECT OF LEPTIN IN IN VITRO MATURATION OF SHEEP OOCYTES” Degree to which it is submitted : MASTER OF VETERINARY SCIENCE Faculty : VETERINARY SCIENCE Discipline : VETERINARY GYNAECOLOGY & OBSTETRICS Chairman : Dr. G. ARUNA KUMARI University : SRI VENKATESWARA VETERINARY UNIVERSITY TIRUPATI - 517 502 Year of Submission : 2015 like slicing, aspiration and post aspiration slicing method. The percentage of good quality oocytes was higher in the aspiration method (65.8%), compared to the slicing (54.2 %) and post aspiration slicing method (36.1 %). In Experiment 2, the effect of season like winter, spring and summer consequently affecting sheep oocytes quality and numbers. The oocytes recovery recorded during spring (March-April) was significantly higher during 506±4.4, 353.30±2.3 and 145±2.7 of A, B and C grade oocytes respectively. On winter (January- February) the quality of oocytes were grade A 335.3±5.7, grade B 245.48±2.1 and grade C 86±5.2. Very less number of Grade A 180±5.5, grade B 143.28±1.7 and grade C53.1±2.6 oocytes were recovered on summer (May-June). The highest number of oocytes recovered during spring (March-April) 1980 followed by 766 during winter (January-February) and 495 during summer (May-June). Experiment 3 was conducted to determine the effect of presence of corpus luteum on oocyte yield. Total 311 ovaries without CL and 104 ovaries with CL yielded 586 oocytes and 143 oocytes respectively. On an average 1.88±0.14 oocytes per ovary were recovered from ovaries without corpus luteum as compared to ovaries with corpus luteum 1.37±0.1. The objective of Experiment -4 was to identify the effect of leptin on in vitro development of sheep oocytes. The In vitro maturation status of sheep oocytes by using different concentration of leptin 10 ng, 20 ng, 50 ng and 100 ng/ml were studied and the IVM (in vitro maturation) status of sheep oocytes were compared with leptin in combination with traditional IVM medium. Total 3150 oocytes were equally divided in two experimental groups. In the first experiment group effect of different concentration of leptin on in vitro maturation was studied. In the second experiment group the effect of different concentration of leptin in combination with IVM medium on oocyte maturation was studied. Five treatments (T1-5) were designed for these experiments. Grades A and B quality sheep oocytes were selected and kept for culture in culture medium with different concentration of leptin. T1: 10 ng/ml, T2: 20 ng/ml, T3: 50 ng/ml T4: 100 ng/ml and T5: control. These culture dishes were incubated at 39oC in 5% CO2 under humidified atmosphere for 24 hrs. The maturation of sheep oocytes were evaluated by observing cumulus cell expansion and extrusion of first polar body (PB) into perivitelline space. Leptin-20 ng/ml significantly enhances ability of in vitro maturation of sheep oocytes as compared to 10 ng/ml, 50 ng/ml and 100 ng/ml of leptin. Moreover the leptin-20 ng/ml shows COC (cumulus-oocyte complexes) expansion (76.80±1.59) and polar body extrusion (50.63±3.94) whereas leptin-20ng/ml with IVM medium also exhibited COC (cumulus-oocyte complexes) expansion (81.90±1.87) and polar body extrusion (56.87±2.92). Leptin - 20ng/ml with IVM medium shows best result on in vitro maturation of sheep oocytes. Present study suggested that on oocyte retrieval method percentage of grade A and B quality oocytes was higher in the aspiration method. During spring (March-April) sheep oocytes quality and numbers were better as compare to winter and summer season. The ovary with a corpus luteum yielded significantly lower number of oocytes than ovary without a corpus luteum. Supplementation of leptin - 20ng/ml with IVM medium showed better result on in vitro maturation of sheep oocytes. Addition of leptin significantly improved the in vitro development of sheep oocytes.
Subject: Veterinary Gynaecology and Obstetrics
These Type: M.SC
Issue Date: 2015-11-07
Appears in Collections:Thesis

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