Ruminants are the only extant mammalian group possessing bony (osseous) headgear. We obtained 221 transcriptomes from bovids and cervids and sequenced three genomes representing the only two pecoran lineages that convergently lack headgear. Comparative analyses reveal that bovid horns and cervid antlers share similar gene expression profiles and a common cellular basis developed from neural crest stem cells. The rapid regenerative properties of antler tissue involve exploitation of oncogenetic pathways, and at the same time some tumor suppressor genes are under strong selection in deer. These results provide insights into the evolutionary origin of ruminant headgear as well as mammalian organ regeneration and oncogenesis.

Mammalian skeletal muscles comprise different types of muscle fibers, and this muscle fiber heterogeneity is generally characterized marked by the expression of myosin heavy chain (MyHC) isoforms. A INTRODUCTIONhttps://www.jbc.org/cgi/

Fermentation has attracted increasing attention in pig industry, because of low costs and numerous benefits on pig growth and health as well as environmental improvement, although the mechanisms remain largely unknown. In the present study, fermented corn-soybean meal significantly improved average daily gain and gain:food ratio (P < 0.05). Fermented feed (FF) significantly increased insulin-like growth factor 1 (IGF1) transcription in liver (P < 0.05). Meanwhile, fermented meal significantly enhanced the binding of CCAAT/enhancer-binding protein beta (C/EBPβ) to IGF1 promoter and C/EBPβ expression in liver (both P < 0.05). FF tended to increase IGF1 proteins in liver and serum too (both 0.05 < P < 0.10). Meanwhile, FF slightly but significantly increased hepatic and circulating triglyceride and total cholesterol levels, as well as serum ratio of high-density to low-density cholesterol (all P < 0.05). Our data indicated that FF could significantly augment the binding of C/EBPβ to IGF1 promoter and promote hepatic IGF1 expression and production, thus boost pig growth.

MicroRNA (miRNA) is essential for the process of gene posttranscriptional regulation in skeletal muscle of many species, such as mice, cattle and so on. However, a little number of miRNAs have been reported in the muscle development of Chinese native pig breeds. In this study, the longissimus dorsi transcripts of Chinese native Rongchang pig at weaning and slaughter time points were analysed for miRNA‐seq. The results showed that 19 novel and 186 known miRNAs involved in the Rongchang pig skeletal muscle development were identified. Based on these findings, we further confirmed that porcine miR‐127, miR‐299 and miR‐432‐5p were obviously down‐expressed in adult pig (287 days of age), while miR‐7134‐3p and 664‐5p were significantly up‐expressed in weaning pig (35 days of age). In other words, these miRNAs could be the potential molecular markers and play vital roles in the muscle development process. Moreover, we found miR‐127 could inhibit the proliferation and myogenesis of porcine satellite cells in longissimus dorsi muscle. Our findings will provide deep insight into miRNA function for pork quality research with Chinese indigenous pig breeds.

The miR-129 family is widely reported as tumor repressors, while, their roles in skeletal muscle have not been fully investigated. Here, the function and mechanism of miR-129-5p in skeletal muscle, a member of the miR-129 family, were explored using C2C12 cell line. Our study shown that miR-129-5p was widely detected in mouse tissues, with the highest expression in skeletal muscle. Gain- and loss-of-function study shown that miR-129-5p could negatively regulate myogenic differentiation, indicated by reduced ratio of MyHC-positive myofibers and repressed expression of myogenic genes, such as MyoD, MyoG and MyHC. Furthermore, miR-129-5p was more enriched in fast extensor digitalis lateralis (EDL) than in slow soleus (SOL). Enhanced miR-129-5p could significantly reduce the expression of mitochondrial cox family, together with that of MyHC I, and knockdown of miR-129-5p conversely increased the expression of cox genes and MyHC I. Mechanistically, miR-129-5p directly targeted the 3'-UTR of Mef2a, which was suppressed by miR-129-5p agomir at both mRNA and protein levels in C2C12 cells. Moreover, overexpression of Mef2a could rescue the inhibitory effects of miR-129-5p on the expression of myogenic factors and MyHC I. Collectively, our data revealed that miR-129-5p as a negative regulator of myogenic differentiation and slow fiber gene expression, thus affecting body metabolic homeostasis.