Association of FATP1 gene polymorphisms with chicken carcass traits in Chinese meat-type quality chicken populations

Genotype frequency distributions of 28 SNP markers in two commercial lines and five Chinese native chicken populations

Background

Modern breeding in the poultry industry mainly aims to produce high-performance poultry lines and breeds in two main directions of productivity, meat and eggs. To understand more about the productive potential of lowly selected Chinese native chicken populations, we selected 14 representative SNP markers strongly associated with growth traits or carcass traits and 14 SNP markers strongly associated with egg laying traits through previous reports. By using the MassArray technology, we detected the genotype frequency distributions of these 28 SNP markers in seven populations including four lowly selected as well as one moderately selected Sichuan native chicken populations, one commercial broiler line and one commercial layer line.

Results

Based on the genotype frequency distributions of these 28 SNP markers in 5 native chicken populations and 2 commercial lines, the results suggested that these Chinese indigenous chicken populations have a relatively close relationship with the commercial broiler line but a marked distinction from the commercial layer line. Two native chicken breeds, Shimian Caoke Chicken and Daheng Broilers, share similar genetic structure with the broiler line.

Conclusions

Our observations may help us to better select and breed superior domestic chickens and provide new clues for further study of breeding programs in local chicken populations.

Feeding conditions and breed affect the level of DNA methylation of the mitochondrial uncoupling protein 3 gene in chicken breast muscle

To investigate the effects of feed condition and breed on the level of DNA methylation for the uncoupling protein 3 (UCP3) gene, which is an important candidate gene for regulating intramuscular fat (IMF) content in chicken breast muscle, breast muscle of Daninghe (DNH) and Qingjiaoma (QJM) chickens under scatter-feed and captivity-feed conditions was analyzed. Using RNA sequencing, 47 and 113 candidate genes were determined to be related to feed conditions and breed, respectively, and 7 differentially expressed genes were confirmed by real-time quantitative PCR, including UCP3. The mRNA levels of UCP3 were significantly different between the 2 feed conditions. The DNA region from bp +1700 to +2459 of the UCP3 gene was studied using the bisulfite sequencing method and contained 46 methylation sites and 3 CpG islands. The results showed that the methylation level of this UCP3 region was lower in DNH chickens (0.77% to 0.88%, P = 0.012) and QJM chickens (0.88% to 0.91%, P = 0.20) under scatter-feed conditions than under captivity-feed conditions. The mean methylation level of UCP3 in DNH chickens was lower than that in QJM chickens under scatter-feed conditions (DNH to QJM, 0.77% to 0.88%, P = 0.007), which suggests that breed affects the mean methylation level of UCP3 under scatter-feed conditions. In summary, our findings suggest that feed condition and breed affect the methylation of UCP3 in chicken breast muscle.

Age-related expression profile of the SLC27A1 gene in chicken tissues

The solute carrier family 27 (SLC27, also known as fatty acid transport proteins [FATPs]) plays important biological roles in cells. However, there is no report about the expression profile of SLC27 member in chicken. In this study, we quantified the expression of SLC27A1 (FATP1) mRNA in a mountainous black-boned chicken breed (MB) and a commercial meat type chicken breed (S01), to discern the tissue and age-related specific expression pattern and their potential involvement in fat deposition and muscle fatty acid metabolism. Real-time quantitative PCR assays were developed for accurate measurement of SLC27A1 mRNA levels in different tissues from chicken with different ages (0-12 weeks). Expression of SLC27A1 mRNA was detected in all tissues examined. There was a significantly age-related change of the SLC27A1 mRNAs in heart, breast muscle (BMW), leg muscle (LMW), liver, and abdominal fat (AF) tissues (P < 0.05). The breast muscle and leg muscle tissues had the highest expression of SLC27A1 mRNA than the other tissues from the same individual at 0, 2 and 4 weeks. The overall SLC27A1 mRNA level exhibited a "rise-decline" developmental change in all tissues except for breast muscle, subcutaneous fat, and brain. The S01 chicken had a higher expression of the SLC27A1 mRNA in breast muscle, subcutaneous fat, and heart tissues than the MB chicken. Our results showed that the expression of SLC27A1 mRNA in chicken tissues exhibits specific developmental changes and age-related patterns.