Differential expression analysis of meat tenderness governing genes in different skeletal muscles of bovines

Expression mechanisms of mir-486-5p and its host gene sANK1 in porcine muscle

BACKGROUND

MiR-486-5p has been identified as a crucial regulator of the PI3K/AKT signalling pathway, which plays a significant role in skeletal muscle development. Its host gene, sANK1, is also essential for skeletal muscle development. However, the understanding of porcine miR-486-5p and sANK1 has been limited.

METHODS AND RESULTS

In this study, PCR analyses revealed a positive correlation between the expression of miR-486-5p and sANK1 in the longissimus dorsi muscle of the Bama mini-pig and Landrace-pig, as well as during myoblast differentiation. Furthermore, the expression of miR-486-5p/sANK1 was higher in the Bama mini-pig compared to the Landrace-pig. There was a total of 18 single nucleotide polymorphisms (SNP) present in the sANK1 promoter region. Among these SNPs, 14 of them resulted in alterations in transcription factor binding sites (TFBs). Additionally, the promoter fluorescence assay demonstrated that the activity of the sANK1 promoter derived from the Bama mini-pig was significantly higher compared to Landrace-pig. It is worth noting that ten regulatory SNPs have the potential to influence the activity of the sANK1 promoter. A nuclear mutation A-G located at position - 401 (relative to the transcription start site) in the Bama mini-pig was identified, which creates a putative TFB motif for MyoD.

CONCLUSIONS

The findings presented in this study offer fundamental molecular knowledge and expression patterns of miR-486-5p/sANK1, which can be valuable for gaining a deeper understanding of the gene's involvement in porcine skeletal muscle development, and meat quality.

Relationship Between Meat Quality, Carcass Characteristics, and Protein Abundance of HSPβ1, HSPA, and DJ1 in Beef Longissimus thoracis Pre-Rigor or After 14 Days’ Aging

This study evaluated associations of heat shock proteins (HSP) and an oxidative stress protein, protein deglycase (DJ1), with beef quality and tenderness. Samples from the longissimus thoracis (N = 99) were collected pre-rigor (day 0) and after 14-d aging. Warner-Bratzler shear force (WBSF), myofibrillar fragmentation index (MFI), and a trained sensory panel were used to determine meat quality. Protein abundance of DJ1 and 2 HSP—HSPβ1 and HSPA—were assessed. Regression analyses demonstrated that DJ1 abundance after 14 d of aging is a predictor of WBSF (P < 0.001), MFI (P = 0.02), and sensory panel tenderness (P < 0.001). Abundance of HSPβ1 after 14 d of aging is also a predictor of MFI (P = 0.03). Additionally, abundance of both HSPβ1 and DJ1 pre-rigor are predictors of juiciness (P < 0.05). Abundance of HSPβ1 pre-rigor was correlated with WBSF (R = 0.67), sensory panel tenderness (R = −0.44), juiciness (R = −0.30), and umami (R = −0.20). Abundance of DJ1 pre-rigor was also correlated with WBSF (R = 0.72), sensory panel tenderness (R = −0.44), juiciness (R = − 0.24), and umami (R = −0.31). After 14-d aging, HSP β 1 abundance was cor- related with WBSF (R = 0.66), sensory panel tenderness (R = −0.34), juiciness (R = −0.34), umami (R = −0.33), and brown/ roasted (R = −0.30). Abundance of DJ1 after 14-d aging was also correlated with WBSF (R = 0.68), sensory panel tenderness (R = −0.41), juiciness (R = −0.21), and umami (R = −0.28). These results demonstrate that abundance of HSPβ1 and DJ1 both pre-rigor and after 14 d of aging are correlated with meat tenderness and end-product quality as assessed by a trained sensory panel. Regression analyses further reveal that abundance of DJ1 and HSPβ1 after 14 d of aging is causative in development of beef tenderness and juiciness, respectively. Taken together, these results suggest that abundance of DJ1 is a predictor of tenderness, whereas abundance of HSPβ1 is related to meat quality but cannot be used to predict tenderness.