ANALYSIS OF DIFFERENTIALLY EXPRESSED GENES RELATED TO INTRAMUSCULAR FAT AND CHEMICAL COMPOSITION IN DIFFERENT BREEDS OF CHICKEN.

Chemical composition traits, for instance, intramuscular fat (IMF) are an important meat quality trait. However, the molecular mechanisms related to IMF deposition in skeletal muscle have not previously been discussed for the native Yunnan (Wuding, Mini, and Wuliangshan) chicken breeds. In order to determine important discrepancies in IMF content, the chemical composition, and phenotypical variations in the gene expression of different breeds, five genes related to fat metabolism were analyzed in the muscle tissues of twenty-week-old native Yunnan breeds and the commercial broiler breed through quantitative reverse transcription PCR (qRT-PCR). The results were a clear statement that breeds had significant effects on LPL, UCP, FAS, FATP1, and PPAR-a gene expression. Higher (P<0.05) LPL gene, UCP gene, and FAS gene expression were observed in the muscles of the Wuding chicken. In comparison, higher (P<0.05) muscle FATP1 gene expression was found in the Mini chicken. The levels of PPAR-a gene (PPAR-a) mRNA were greatest (P<0.05) in the Wuding, moderate (P<0.05) in the Mini, and lowest in the Wuliangshan and the broiler. Chemical composition exhibited the lowest IMF content in the broiler thigh and breast muscle. In the thigh muscles, the Wuding chicken had the highest IMF content, while the Mini chicken had higher crude protein levels and ash content. In comparison, the breast muscles of the Wuliangshan had higher crude fat, protein, and ash content followed by those of the Wuding and the Mini. Variations in gene expression in different breeds and their relationship to chemical composition could contribute to the distinct fatty phenotype and characteristic flavor of native Yunnan chicken. The identification of variations in gene expression could facilitate targeted sequencing and genotyping efforts for advanced studies. [ABSTRACT FROM AUTHOR]