Intramuscular fat (IMF) content in pork is an important element of consumer preference and is positively correlated with meat quality, including tenderness and juiciness. With advances in RNA sequencing technologies, transcriptome-related differences can be associated with specific traits in animals. The objective of this study was to investigate differentially expressed genes (DEGs) closely related to IMF content in porcine longissimus muscle using RNA sequencing. A total of 107 Berkshire pigs were used for IMF content measurements, and significant differences between extremely high (H, n = 3) and low (L, n = 3) IMF content groups were found (P < 0.0001). From multi-dimensional scaling analyses, it was observed that the relationships between H and L groups were similar to each other. Here, we identified a total of 134 genes that were differentially expressed between the groups (false discovery rate <0.05; fold change ≥2). Functional analyses with DEGs revealed that lipid metabolism (SCD and FASN) was one of the significant biological processes related to IMF content determination. In addition, we found that DEGs related to muscle regeneration (MYOG and VEGFA) and extracellular matrix (COL1A1, COL1A2, COL5A1, COL14A1 and COL15A1) were changed among individuals with extreme IMF contents. These results will aid in understanding the regulation of IMF content in pigs.

Substance P (SP) can stimulate production of tumor necrosis factor-alpha (TNF-alpha) from astrocytes stimulated with lipopolysaccharide (LPS). The objective of the current study was to determine the effect of Taraxacum officinale (TO) on the production of TNF-alpha from primary cultures of rat astrocytes. TO (100 and 1000 microg/ml) significantly inhibited the TNF-alpha production by astrocytes stimulated with LPS and SP. Interleukin-1 (IL-1) has been shown to elevate TNF-alpha production from LPS-stimulated astrocytes while having no effect on astrocytes in the absence of LPS. We therefore examined whether IL-1 mediated inhibition of TNF-alpha production from primary astrocytes by TO. Treatment of TO (100 and 1000 microg/ml) to astrocytes stimulated with both LPS and SP decreased IL-1 production significantly. Moreover, the production of TNF-alpha by LPS and SP in astrocytes was progressively inhibited with increasing amount of IL-1 neutralizing antibody. Our results suggest that TO may inhibit TNF-alpha production by inhibiting IL-1 production and that TO has an antiinflammatory activity in the central nervous system.

White Pekin duck is an important meat resource in the livestock industries. However, the temperature increase due to global warming has become a serious environmental factor in duck production, because of hyperthermia. Therefore, identifying the gene regulations and understanding the molecular mechanism for adaptation to the warmer environment will provide insightful information on the acclimation system of ducks. This study examined transcriptomic responses to heat stress treatments (3 and 6 h at 35 °C) and control (C, 25 °C) using RNA-sequencing analysis of genes from the breast muscle tissue. Based on three distinct differentially expressed gene (DEG) sets (3H/C, 6H/C, and 6H/3H), the expression patterns of significant DEGs (absolute log2 > 1.0 and false discovery rate < 0.05) were clustered into three responsive gene groups divided into upregulated and downregulated genes. Next, we analyzed the clusters that showed relatively higher expression levels in 3H/C and lower levels in 6H/C with much lower or opposite levels in 6H/3H; we referred to these clusters as the adaptable responsive gene group. These genes were significantly enriched in the ErbB signaling pathway, neuroactive ligand-receptor interaction and type II diabetes mellitus in the KEGG pathways (P < 0.01). From the functional enrichment analysis and significantly regulated genes observed in the enriched pathways, we think that the adaptable responsive genes are responsible for the acclimation mechanism of ducks and suggest that the regulation of phosphoinositide 3-kinase genes including PIK3R6, PIK3R5, and PIK3C2B has an important relationship with the mechanisms of adaptation to heat stress in ducks.