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Assam Agricultural University, Jorhat

Assam Agricultural University is the first institution of its kind in the whole of North-Eastern Region of India. The main goal of this institution is to produce globally competitive human resources in farm sectorand to carry out research in both conventional and frontier areas for production optimization as well as to disseminate the generated technologies as public good for benefitting the food growers/produces and traders involved in the sector while emphasizing on sustainability, equity and overall food security at household level. Genesis of AAU - The embryo of the agricultural research in the state of Assam was formed as early as 1897 with the establishment of the Upper Shillong Experimental Farm (now in Meghalaya) just after about a decade of creation of the agricultural department in 1882. However, the seeds of agricultural research in today’s Assam were sown in the dawn of the twentieth century with the establishment of two Rice Experimental Stations, one at Karimganj in Barak valley in 1913 and the other at Titabor in Brahmaputra valley in 1923. Subsequent to these research stations, a number of research stations were established to conduct research on important crops, more specifically, jute, pulses, oilseeds etc. The Assam Agricultural University was established on April 1, 1969 under The Assam Agricultural University Act, 1968’ with the mandate of imparting farm education, conduct research in agriculture and allied sciences and to effectively disseminate technologies so generated. Before establishment of the University, there were altogether 17 research schemes/projects in the state under the Department of Agriculture. By July 1973, all the research projects and 10 experimental farms were transferred by the Government of Assam to the AAU which already inherited the College of Agriculture and its farm at Barbheta, Jorhat and College of Veterinary Sciences at Khanapara, Guwahati. Subsequently, College of Community Science at Jorhat (1969), College of Fisheries at Raha (1988), Biswanath College of Agriculture at Biswanath Chariali (1988) and Lakhimpur College of Veterinary Science at Joyhing, North Lakhimpur (1988) were established. Presently, the University has three more colleges under its jurisdiction, viz., Sarat Chandra Singha College of Agriculture, Chapar, College of Horticulture, Nalbari & College of Sericulture, Titabar. Similarly, few more regional research stations at Shillongani, Diphu, Gossaigaon, Lakhimpur; and commodity research stations at Kahikuchi, Buralikson, Tinsukia, Kharua, Burnihat and Mandira were added to generate location and crop specific agricultural production packages.

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20221
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Subject: Animal Genetics and Breeding × Author: Lalmasawma, Timothy × End date: 2022 × Thesis Type: Ph.D ×
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    ThesisItemOpen Access
    Isolation, characterization and morpho-biometric evaluation of pre-pubertal porcine spermatogonial stem cells in different culture media
    (College of Veterinary Science, Assam Agricultural University, Khanapara Campus, 2022-03) Lalmasawma, Timothy; Das, Arpana
    Testes samples were collected from 7-15 days old pre-pubertal male crossbred piglets (Local × Hampshire) for isolation, enrichment and in vitro culture of porcine spermatogonial stem cells (SSCs). Isolation of spermatogonial stem cells like cells was performed by double enzymatic digestion using four enzymes viz., collagenase, DNase I, hyaluronidase type II and trypsin-EDTA. Isolated cells were further enriched by differential plating and percoll density gradient centrifugation method. Enriched cells were cultured on Sertoli cell feeder layer in three different culture media. All the three media consisted of same concentration of DMEM, NEEA, L-glutamine, FBS, EGF and FGF, however in addition to these, LIF was added to media I, GDNF was added to media II and both LIF and GDNF were added to media III. Characterization of SSCs was done by alkaline phosphatase and immunoflourescence staining. Expression of SSC specific pluripotent marker genes by putative SSCs was also studied by RT-PCR study. Porcine SSCs were observed as dome shaped round or oval bodies on 5th -6th day of culture in all the three media. Clustering of cell was observed from 4th -5th day of culture and single, paired or multiple colonies were observed from 8-10th day of culture. The SSCs colonies appeared as mulberry, grape or rosette shaped with irregular distinct boundary from feeder layer on 15th - 19th day of culture in all the three media. However, the shape of the SSCs was found to be distorted with increase in the days of culture. The morphology of the SSC colonies was maintained best up to 30th day of culture in media III. The SSC colony number was recorded as 82.14 ± 2.91, 60.07 ± 2. 78 and 48.43 ± 1.96 on 5th, 15th and 30th day of culture respectively in media I. The corresponding numbers were 91.71 ± 2.62, 67.00 ± 2.05 and 57.29 ± 2.17 in media II and 105.93 ± 2.82, 80.21 ± 2.45 and 62.50 ± 2.09 in media III respectively. The SSC colony diameter was found to be 64.26 ± 0.85, 125.30 ± 1.88 and 123.01 ± 5.49μm on 5th, 15th and 30th day of culture respectively in media I. The corresponding values were 69.67 ± 1.12, 139.58 ± 3.93 and 142.08 ± 5.72μm in media II and 76.49 ± 1.61, 152.55 ± 4.07 and 172. 08 ± 4.96μm in media III respectively. The day of culture and culture media had significant effect (P≥0.01) on SSC colony number and significantly higher number of SSC colony was observed on day 5 and lower was on day 30 of culture in all the three media. The SSC colony number was significantly higher in media III containing both GDNF and LIF. The diameter of SSC colony differed significantly (P≥0.05) due to day of culture and culture media. The interaction between day of culture and culture media was also significant (P≥0.01). The colony diameter recorded on day 30 of culture was significantly higher, whereas lower number was recorded on day 5 of culture in all the culture media. Diameter of SSC colony obtained in media III was found to significantly higher and the lower diameter was obtained in media I on all the day of culture. It was observed that the SSC colony number decreased and colony diameter increased with the day of culture from day 5th to 30th day of culture in all the media.The putative SSCs in all the three media showed positive result for alkaline phosphatase and immunofluorescence staining. The putative SSCs in all the three media were also found to express SSC specific pluripotent marker genes viz., OCT4, SOX2, NANOG and maximum expression was observed in media III, however, no expression was recorded for c-KIT and PPARγ which were known to be the markers for differentiated SSCs. BAX4, an apoptopic marker gene was also expressed by putative SSCs in all the three media. Based on the findings of the present study, it may be concluded that a pure population of porcine spermatogonial stem cells (SSCs) could be obtained and successfully maintained in vitro up to 30th day of culture. Media III containing DMEM, FBS, NEAA, L-glutamin, FGF, EGF, LIF and GDNF was found to be the best for in vitro culture of porcine SSCs.