Lower Expression of SLC27A1 Enhances Intramuscular Fat Deposition in Chicken Via Down-Regulated Fatty Acid Oxidation Mediated by CPT1A

Purpose: The goals of this study are to investigate the differentially expressed genes between High IMF chickens (WC) and Low IMF chickens (WRR) breast muscles by Illumina deep sequencing, to reveal the mechanism underlying chicken IMF deposition. Methods: Both WC chickens and WRR chickens were raised up to 120 d of age (D120) or 180 d of age (D180), two female birds of similar weight from each breed per age were subjected to RNA-sequencing by Illumina Hiseq 2000. So eight muscle samples in total were subjected to RNA-seq analysis, four WC chicken samples including WC.D120.B-1, WC.D120.B-3, WC.D180.B-2 and WC.D180.B-3, and four WRR chicken samples including WRR.D120.B-4, WRR.D120.B-6, WRR.D180.B-2 and WRR.D180.B-5. Results: The clean reads of each sample were over 20 million, the expressed genes ranged from 16202 to 17838, and a little higher in WRR samples than in WC samples. Differentially expresse analysis showed that there were 525, 161, 23, 87 DEGs detected in the comparisons of WRR.D120.B-VS-WC.D120.B, WRR.D180.B-VS-WC.D180.B, WC.D120.B-VS-WC.D180.B and WRR.D120.B-VS-WRR.D180.B, respectively. Many genes related to lipid catabolism were down-regulated in WC chickens. Conclusions: Our present study suggest that lower lipid catabolism exists in WC chickens but not in WRR chickens, and lower expression of SLC27A1 is through down-regulating fatty acid oxidation mediated by CPT1A to facilitate IMF deposition. Moreover, these findings indicate that reduced lipid catabolism, rather than increased lipid anabolism, contributes to chicken IMF deposition. Overall design: Two female birds from WC and WRR chickens at 120 d of age (D120) and 180 d of age (D180) respectively were subjected to RNA-sequencing by Illumina Hiseq 2000.

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