Cloning, Expression and Modeling Studies of Somatotropin cDNA of Local Buffalo Breed-Nili Ravi

Pakistan is primarily an agricultural country and livestock is a very important means of livelihood resource for millions of people in Pakistan. It not only provides essentials for human life in the form of milk, meat and eggs but also wool, hair, skin, blood, bones and manure. Buffalo, one of the important domesticated animals in Pakistan, is not only popular for milk but also for meat. With an increasing human population and rising standards of living the demand for milk and meat is also increasing. With availability of recombinant technology, somatotropin (ST), a non-glycosylated protein hormone, can bring about ten to forty percent increase in milk yield when it is injected into the milking species. Due to its importance in milk and meat production ST cDNA has been cloned from a number of species. We have cloned, sequenced and expressed the ST cDNA from a local buffalo breed: Niti ravi and carried out comparative modeling study. For this purpose total cellular RNA was extracted from the pituitary gland of Nili ravi, cDNA was synthesized and ST cDNA was amplified with the help of sets of primers designed on the basis of sequence data available from NCB1 Gene Bank. The PCR amplified products were cloned in T/A cloning vector, sequenced and then put in pLEX expression vector to carry out expression studies. The ST cDNA sequence was further subjected to various modelling softwares to obtain a validated 3D model of the protein.