Effects of muscle fiber type on glycolytic potential and meat quality traits in different Tibetan pig muscles and their association with glycolysis-related gene expression

Abstract

ABSTRACT. The myosin heavy chain (MyHC) composition, glycolytic potential, mitochondrial content, and gene expression related to energy metabolism were analyzed in eight muscles from Tibetan pigs, to study how meat quality develops in different muscle tissues. The muscles were classified into three clusters, based on MyHC composition: masseter, trapezius, and latissimus dorsi as 'slow-oxidative-type'; psoas major and semimembranosus as 'intermediate-type'; and longissimus dorsi, obliquus externus abdominis, and semitendinosus as 'fast-glycolytic-type'. The 'slowoxidative-type' muscles had the highest MyHC I and MyHC IIA content (P < 0.01); 'intermediate-type' muscles, the highest MyHC IIx content (P < 0.01); and 'fast-glycolytic-type' muscles, the highest MyHC IIb content (P < 0.01).The pH values measured in 'slow-oxidative-type' muscles were higher than those in the other clusters were; however, the color of 'fast-glycolytictype' muscles was palest (P < 0.01). Mitochondrial content increased in 14367 Effects of muscle fiber type on meat quality ©FUNPEC-RP www.funpecrp.com.br Genetics and Molecular Research 14 (4): 14366-14378 (2015) the order: fast-glycolytic-type < intermediate-type < slow-oxidative-type. In the 'slow-oxidative-type' muscles, the expression levels of genes related to ATP synthesis were higher, but were lower for those related to glycogen synthesis and glycolysis. Mitochondrial content was significantly positively correlated with MyHC I content, but negatively correlated with MyHC IIb content. MyHC I and mitochondrial content were both negatively correlated with glycolytic potential. Overall, muscles used frequently in exercise had a higher proportion of type I fibers. 'Slow-oxidative-type' muscles, rich in type I fibers with higher mitochondrial and lower glycogen and glucose contents, had a higher ATP synthesis efficiency and lower glycolytic capacity, which contributed to their superior meat quality.

Genome-wide landscape of DNA methylomes and their relationship with mRNA and miRNA transcriptomes in oxidative and glycolytic skeletal muscles

“…For example, HK-2 , a key gene involved in these processes, plays an important role in encoding the first rate-limiting enzyme catalyzing the glycogen degradation reaction through glycolysis. It has previously been reported that HK-2 is positively correlated with glycolytic potential and is less strongly expressed in slow-oxidative-type muscle49, a result consistent with the present findings that the high methylation status of HK-2 resulted in lower mRNA expression levels in PMM (Fig. 5c).…”

Proteomic signature of muscle fibre hyperplasia in response to faba bean intake in grass carp

“…Similar experiments have been carried out on other fish species, with the anaerobic metabolism found to accelerate with increasing muscle hardness in Atlantic salmon48. In addition, the glycolytic pathway has also been investigated in pork of different qualities, revealing that the expression of glyceraldehyde-3-phosphate dehydrogenase and lactate dehydrogenase is significantly increased in pork with a hard texture49. However, the specific mechanism of the glycolytic metabolic pathway during muscle hardening remains to be elucidated.…”

Screening for candidate genes related with histological microstructure, meat quality and carcass characteristic in pig based on RNA-seq data

“…Based on findings of other authors indicating relations of histological structure and meta quality and carcass traits [ 10 – 12 ], we also performed an association study on a large number of pigs. For this analysis four genes were selected: TNNT2 ; FOXO1 ; TACC2 ; DEGS1 .…”

“…It has been well-established that percentage number of fiber types in muscle determines metabolic properties and water holding capacity of muscle tissue, as well as marbling, intramuscular fat (IMF) level, meat color and texture [ 10 – 12 ]. In our previous study performed on Large White pigs, we identified genes differentially expressed in muscle contingent on histological microstructure [ 13 ].…”