No abstract

Intramuscular fat (IMF) is one of the crucial factors determining meat quality. IMF deposition depends on the hyperplasia and hypertrophy of intramuscular preadipocytes, in which genes and noncoding RNAs play an important regulatory role. According to previous transcriptome analysis, ANXA6 and miR-24-3p were identified as involved in lipid metabolism in breast muscle. In this study, we further investigated their function in the proliferation and differentiation of chicken intramuscular preadipocytes. The results indicated that overexpression of ANXA6 inhibited proliferation and promoted differentiation of intramuscular preadipocytes, while knockdown of ANXA6 promoted cell proliferation and inhibited adipogenic differentiation. miR-24-3p was proved to directly bind to the 3′ untranslated region (3′UTR) of ANXA6 by dual-luciferase reporter assay. The regulatory effect of miR-24-3p on the proliferation and differentiation of intramuscular preadipocytes was opposite to that of ANXA6. Besides, the overexpression vector of ANXA6 eliminated the impact of miR-24-3p mimics on intramuscular preadipocytes. In brief, we revealed that miR-24-3p promoted proliferation but inhibited differentiation of intramuscular preadipocytes by blocking ANXA6 expression, thus dominating IMF deposition in broilers. These findings may provide a novel target for improving chicken meat quality.

No abstract

The composition and content of amino acids in foodstuffs have a vital impact on the nutritional value and taste. With the aim of understanding the nutrition and flavor of Guangyuan grey chicken, the composition and content of amino acids in the pectoralis and thigh muscle of chickens at the age of 90 d, 120 d and 150 d were determine using liquid chromatography–tandem mass spectrometry (LC-MS/MS) and an amino acid analyzer. A total of 17 amino acids were detected both in pectoralis and thigh muscle via the amino acid analyzer, of which the content of glutamate was the highest. Additionally, 21 deproteinized free amino acids were detected via LC-MS/MS. Among all samples, the content of glutamine in thigh muscle was the highest. The content of histidine in the pectoralis was the highest. In terms of the flavor amino acids (FAAs), the umami-taste and sweet-taste amino acids were higher in the thigh muscle of 120 d male chicken. From the perspective of protein nutrition, the essential amino acid was higher in pectoral muscle, and the composition was better. The results of the amino acid score showed that the content of leucine and valine were inadequate in Guangyuan grey chicken. Collectively, the content of amino acid in Guangyuan grey chicken was affected by age, gender and meat cut. This study confirms that meat of chicken in different ages, genders, and cuts presents different nutritional values and flavors owing to the variation of amino acids content.

No abstract