The study presents the miRNA profiles of two Indian sheep populations with divergent carcass and muscle traits. The RNA sequencing of longissimus thoracis muscles from the two populations revealed a total of 400 known miRNAs. Myomirs or miRNAs specific to skeletal muscles identified in our data included oar-miR-1, oar-miR-133b, oar-miR-206 and oar-miR-486. Comparison of the two populations led to identification of 100 differentially expressed miRNAs (p < 0.05). A total of 45 miRNAs exhibited a log2 fold change of ≥ ( ±) 3.0. Gene Ontology analysis revealed cell proliferation, epithelial to mesenchymal transition, apoptosis, immune response and cell differentiation as the most significant functions of the differentially expressed miRNAs. The differential expression of some miRNAs was validated by qRT-PCR analysis. Enriched pathways included metabolism of proteins and lipids, PI3K-Akt, EGFR and cellular response to stress. The microRNA-gene interaction network revealed miR-21, miR-155, miR-143, miR-221 and miR-23a as the nodal miRNAs, with multiple targets. MicroRNA-21 formed the focal point of the network with 42 interactions. The hub miRNAs identified in our study form putative regulatory candidates for future research on meat quality traits in Indian sheep. Our results provide insight into the biological pathways and regulatory molecules implicated in muscling traits of sheep.

The dynamic synergy of genes and pathways in muscles in relation to age affects the muscle characteristics. Investigating the temporal changes in gene expression will help illustrate the molecular mechanisms underlying muscle development. Here we report the gene expression changes in skeletal muscles through successive age groups in Bandur, a meat type sheep of India. RNA sequencing data was generated from the longissimus thoracis muscles from four age groups, ranging from lamb to adult. Analysis of 20 highest expressed genes common across the groups revealed muscle protein, phosphorylation, acetylation, metal binding and transport as significant functions. Maximum differentiation was observed after 2.5–3 years on transition from lambs to adult. Transcriptional regulation by the TFAP2 transcription factors, IL-6 signaling and PI3K/AKT signaling pathways were enriched in younger animals. The gene-protein network demarcated key interactive genes involved in muscle development and proliferation that can be used as candidates for future research on improvement of muscle characteristics.

Background: Cystic Ovarian Disease (COD) is an important ovarian dysfunction and a major cause of reproductive failure in dairy cattle. The present study was carried out with the objective to determine the factors influencing Cystic Ovarian Disease in HF crossbred cows. Methods: The study was undertaken on 155 Holstein Friesian (HF) crossbred cows. Age, parity and body condition score (BCS) were recorded. Statistical analysis was done to know the influence of age, parity and BCS on the occurrence of COD by Graph Pad Prism software. Results: Significantly higher proportions of COD cases were reported in the animals of 5 to 7 years age group and least in the age group of greater than 7 years old. Significantly higher proportions of COD cases were observed in 2 nd and 3 rd lactation cows and less in heifers as well as animals in 4 th and above lactation. The incidence of ovarian cysts was highest in the cows having good body condition scoring (BCS-3), followed by cows having very good BCS (3.5), followed by fat cows (BCS-4) and least in animals having BCS 2 and 5. Conclusion: The study revealed that the age, parity and BCS of the animal influence the risk factors for cystic ovarian diseases; however, similar such studies are needed to support the current results.