Association of Single Nucleotide Polymorphisms in Exon 3 of Porcine LMCD1 Gene with Meat Quality and Carcass Traits

LIM domain proteins are found to be important regulators in cell growth, cell fate determination, cell differentiation, and remodelling of the cell cytoskeleton by their interaction with some structural proteins, kinases, transcriptional regulators, etc. The presence of LIM domains in LMCD1 gene implies it may be involved in skeletal muscle protein-protein interactions. This study was to investigate polymorphisms of LIM and cysteine-rich domain 1 （LMCD1） gene and its effect on meat quality and carcass traits in pig. The polymorphism （G294A） in exon 3 region of porcine LMCD1 gene, which is synonymous mutation, was genotyped in the population of 178 F, pigs of a Large White × Meishan resource family. Statistical results indicated the distribution of allele G （with a A → G mutation） and A （without mutation）. Analysis of variance showed that the polymorphism of LMCD1 gene was associated with variation in several carcass traits of interest for pig breeding. Some carcass traits and meat quality traits are close to significance by association. An analysis of more animals is necessary to analyze the polymorphisms in exon 3 of porcine LMCD1 gene if it was selected as a marker for the pig carcass traits.

A genome-wide association study of five meat quality traits in Yorkshire pigs

Meat quality is an important trait in the pig industry.To identify genomic regions and haplotype blocks responsible for meat quality traits in pigs,a genome-wide association study was conducted for five traits including intramuscular fat content,pH at 45 min and 24 h,drip loss within 24 h and water-holding capacity in 231 Yorkshire barrows using illumina porcine 60k SNP chips.The results showed that a total of 344 single nucleotide polymorphisms(SNP)were significantly associated with five meat quality traits(P<1×10^(–4)).Moreover,323 SNPs were within the reported QTL regions,of which 21 were novel.Also,158 SNPs fell into the proximal region of meat quality related genes.In addition,25 haplotype blocks based on 116 SNPs were revealed with SNP combination patterns for five traits.Our study added new SNP information for identification of meat quality traits in pigs and will help elucidate the mechanisms of meat quality in pigs.

Bovine HSD17B8 gene and its relationship with growth and meat quality traits

17 β-Hydroxysteroid dehydrogenase type 8 （HSD17B8） is an important regulator of lipid and steroid metabolism. In the present study, we aimed to assess the effects of HSD17B8 on growth and meat quality traits in cattle. Transcription profile analysis showed that HSD17B8 was primarily expressed in the salpinx, liver, and testis. Meanwhile, we identified three SNPs （SNPI： intron 1-A91G; SNP2： exon 1-A90G; and SNP3： intron 8-A86G） of the bovine HSD17B8 gene and investigated its haplotype frequencies and linkage disequilibrium. The detected SNPs were found associated with growth traits （body weight, body length, height at withers, heart girth, hip width, and average daily gain） in native cattle populations （Nanyang and Jiaxian） as well as the meat quality traits （Warner- Bratzler shear force, rib area, dressing percentage, carcass weight, and backfat thickness） in commercial breeds （Angus, Hereford, Limousin, Luxi, Simmental, and Jinnan）. Our results provided evidence that polymorphisms in the HSD17B8 gene were associated with growth traits and meat quality traits. Moreover, our findings might be used for marker-assisted selection in beef cattle breeding program

MED4 gene positively affects preadipocyte differentiation in Chinese red steppe cattle

Background:The regulatory genes related to lipid metabolism affect the intramuscular fat(IMF)content and improve meat quality traits.Mediator Complex Subunit 4(MED4),a vitamin D receptor protein,affects vitamin D,livestock growth,carcass traits,and triglyceride deposition.However,the physiological function of the MED4 gene on bovine adipocyte differentiation remains unknown.Methods:This study explored the function of the MED4 gene in preadipocyte differentiation in Chinese Red Steppe cattle.The overexpression plasmid and the interference sequences of the MED4 gene were constructed to detect the effects of the MED4 gene on adipogenesis and biomakers using quantitative polymerase chain reaction and western blotting.Results:The MED4 gene had significantly high expression during preadipocyte differentiation(p<0.05).Overexpression of the MED4 gene increased the expression of the PPARγgene,a preadipocyte differentiation biomarker,improved cellular lipid droplets and triglycerides accumulation,and positively accelerated adipocyte maturation(p<0.05).Interference of the MED4 gene can negatively regulate preadipocyte differentiation.Conclusion:This study showed that the MED4 gene may affect the preadipocyte differentiation and adipogenesis in Chinese Red Steppe cattle by regulating the PPARγgene.

Proteome Profiles of Longissimus and Biceps Femoris Porcine Muscles Related to Exercise and Resting

Exercise affects muscle metabolism and composition in the untrained muscles. The proteome of muscle tissue will be affected by exercise and resting. This is of economic importance for pork quality where transportation relates to exercise of untrained muscles. Rest reverses exercise effects. The objective of this research was to develop potential protein biomarkers that predict the optimal resting time after exercise related to optimal pork quality. Ten litters of four female pigs were within litter allocated to the four treatment groups： exercise by running on a treadmill for 27 minutes followed by rest for 0, 1, or 3 h; control pigs without exercise. Proteome profiles and biochemical traits measuring energy metabolism and meat quality traits expected to be related to exercise were determined in the Longissimus and the Biceps femoris of the pigs. The results indicated associations between protein abundances in muscles and exercise, resting, and biochemical traits.