In vitro expression profiling of myostatin, follistatin, decorin and muscle-specific transcription factors in adult caprine contractile myotubes.

Skeletal muscle is one of the several adult postmitotic tissues that retain the capacity to regenerate, which relies on a population of quiescent precursors, termed satellite cells. Proliferation and differentiation of myoblasts to form mature myotubes in vitro has been a valuable tool in the characterization of the cellular events during myogenesis, which is a multistep process starting with progenitor cell proliferation, followed by their exit from the cell cycle, differentiation, alignment, and fusion to form multinucleated myotubes. A typical feature during muscle differentiation is the variation in expression of various genes along with myogenic factors. In this experiment, mRNA level of myostatin, follistatin, decorin and three muscle-specific transcription factors in adult caprine contractile myotubes have been studied through quantitative real time PCR. We observed that the expression level of myostatin, decorin, Myf5 and myogenin transcripts were significantly higher in contractile myotubes compared to myoblast monolayer (P < 0.05), and follistatin level was similar in both types of cells, whereas MyoD transcript level was significantly high in monolayer culture which might be due heterogeneity of myoblast population. It is concluded that the information generated would provide the base line information as well as monitoring markers to undertake experiments aimed at modulating muscle growth.

Test day variability in yield and composition of Surti and Mehsani buffaloes milk at day 15 and 60 postpartum.

AIM: To estimate individual test day variability in yield and composition of Surti and Mehsani buffaloes milk at day 15 and 60 postpartum (pp). MATERIALS AND METHODS: A total of 13 normally calved Surti and Mehsani buffaloes each maintained at Livestock Research Stations of Navsari and Sardarkrushinagar Dantiwada Agricultural Universities, respectively, were selected for the study. Milk sample was collected from each selected buffalo at day 15 and 60 pp to study milk yield and composition variability between these two breeds. Buffaloes were categorized for the ease of data analysis and comparisons into four groups, viz., S15 (Surti buffaloes 15(th) day pp), S60 (Surti buffaloes 60(th) day pp), M15 (Mehsani buffaloes 15(th) day pp), and M60 (Mehsani buffaloes 60(th) day pp). RESULTS: There were 37.20% and 25.03% significant (p≤0.05) increase in mean test day milk yield (TDMY) of S60 and M60 as compared to S15 and M15 groups, respectively. The mean TDMY of Mehsani buffalo was 99.19% and 81.53% significantly (p≤0.05) higher than Surti buffaloes at day 15 and 60 pp, respectively. The mean fat and protein corrected test day milk yield (FPCTDMY) of all the groups was found to be significantly different (p≤0.05) from each other. There was significant (p≤0.05) increase of 1.94 and 3.45 kg in mean FPCTDMY with the progression of lactation between day 15 and 60 pp in Surti and Mehsani buffaloes, respectively. Similarly, the mean FPCTDMY of Mehsani buffaloes were approximately double with 103.27% and 96.36% higher yield as compared to Surti buffaloes at day 15 and 60 pp, respectively. Among milk composition, significant differences were observed for solid not fat (SNF) and protein%, whereas fat and lactose% were steady among four groups. The only significant (p≤0.05) difference was observed for SNF in M60 group, which was 8.29%, 6.85%, and 10.70% higher as compared to S15, S60, and M15 groups, respectively. The mean protein% in milk of Mehsani buffaloes was 21.01% and 33.05% significantly (p≤0.05) higher than Surti buffaloes milk at day 15 and 60 pp, respectively. However, there was a significant difference in protein% observed with the advancement of lactation in Mehsani buffaloes, but it was not so in the case of Surti buffaloes. CONCLUSION: Major consistent finding of the present study reveals that milk yield and protein% of Mehsani buffalo was significantly higher than Surti buffalo at day 15 and 60 pp.