Comparative muscle transcriptome of Mali and Hampshire breeds of pigs: a preliminary study.

Muscle development is an important priority of pig breeding programs. There is a considerable variation in muscularity between the breeds, but the regulation mechanisms of genes underlying myogenesis are still unclear. Transcriptome data from two breeds of pigs with divergent muscularity (Mali and Hampshire) were integrated with histology, immunofluorescence and meat yield to identify differences in myogenesis during the early growth phase. The muscle transcriptomics analysis revealed 17,721 common, 1413 and 1115 unique transcripts to Hampshire and Mali, respectively. This study identified 908 differentially expressed genes (p < 0.05; log2FC > ±1) in the muscle samples, of which 550 were upregulated and 358 were downregulated in Hampshire pigs, indicating differences in physiological process related to muscle function and development. Expression of genes related to myoblast fusion (MYMK), skeletal muscle satellite cell proliferation (ANGPT1, CDON) and growth factors (HGF, IGF1, IGF2) were higher in Hampshire than Mali, even though transcript levels of several other myogenesis-related genes (MYF6, MYOG, MSTN) were similar. The number of fibers per fascicle and the expression of myogenic marker proteins (MYOD1, MYOG and PAX7) were more in Hampshire as compared to Mali breed of pig, supporting results of transcriptome studies. The results suggest that differences in muscularity between breeds could be related to the regulation of myoblast fusion and myogenic activities. The present study will help to identify genes that could be explored for their utility in the selection of animals with different muscularities.

Review on small ruminant conservation status and prospects in India.

Small ruminants always play a major role in the agricultural economy of India. They provide livelihoods to numerous small and marginal farmers. The diversity of small ruminant population is enormous in the country which contributes to agrarian economy. However, the genetic variety is now at risk due to indiscriminate cross-breeding, and change is farmer's preference towards high-producing breeds. The population statistics is showing a declining trend for the past several years. During time of climate change and outbreak of novel diseases, this genetic diversity is important as consumer preferences and climate is bound to change in future. So to ensure fitness and vitality in future populations of food-producing animals, and to keep genetic options open, access to greater diversity of genetic material will always be required. The native breeds of the country also possess several characteristics of disease tolerance, high fecundity and specific products which make them unique in their own aspect. Hence, conservation programmes should be adopted to maintain this large diversity of small ruminants. It may involve tradition practices followed by pastoralists or modern reproductive technologies like MOET. The government has taken several steps towards conservation and national institutes like NBAGR works for evaluation and conservation of native genetic diversity. However, better awareness among famers and improving of conservational approaches will go a long way in sustainable management of sheep and goat genetic resources.