Association of the thyroid hormone responsive spot 14 alpha gene with growth-related traits in Korean native chicken

Thyroid hormone responsive spot 14 alpha (THRSP) has been used to investigate the regulation of de novo lipogenesis because the variation of THRSP mRNA content in the tissue affects directly the ability of that tissue to synthetize lipids. Also, this gene responds to thyroid hormone stimulation and high level of carbohydrate feeding or insulin-injection. This study was carried out to investigate variations within THRSP and their effects on body and carcass weights in Korean native chicken (KNC). A total of 585 chickens which represent the five lines of KNC (Black, Gray-Brown, Red-Brown, White, and Yellow-Brown) were reared and body weight data were recorded every two weeks from hatch until 20 weeks of age. PCR-RFLP, DNA chips for Agilent 2100 Bioanalyzer, and Fluidigm Genotyping Technology, were applied to genotype selected markers. A linear mixed-effect model was used to access association between these SNP markers and growth-related traits. A total of 30 polymorphisms were investigated in THRSP. Of these, nine SNPs for loci were selected to perform association analyses. Significant associations were detected between g.-49G>T SNP with BW20, g.451T>C SNP with GR10-12 trait, and g.1432A>C SNP with GR14-16 trait and BW18. Moreover, diplotype of the THRSP gene significantly affected BW12 and GR10-12 traits. Diplotype of ht1/ht2 was favorable for BW12 and GR10-12 traits. These results suggest that THRSP can be regarded as a candidate gene for growth traits in Korean native chicken.