Abstract：Thyriod hormone responsive spot 14 (THRSP) is a transcriptional regulation factor which participates in regulating the activity of lipogenic enzymes and in turn affects the lipid metabolism in animal tissues. It includes α and β two subtypes. In this study, in order to investigate the effects of THRSPα on the carcass and abdominal fat traits and explore its expression profile in Jinghai Yellow chicken (Gallus gallus), polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP) combining sequencing method was used to detect the polymorphisms of THRSPα , and qRT-PCR technology was applied to analyze the expression level of this gene in 10 tissues (including heart, liver, spleen, lung, kidney, breast muscle, leg muscle, abdominal fat, small intestine and hypothalamus) and the expression profile of this gene from 0 to 16 weeks of age in Jinghai Yellow chicken. As a result, 2 mutations (C129T and T160G) were detected in exon 2 of THRSPα. Three haplotypes and 5 diplotypes were formed in the group of Jinghai Yellow chicken. Association analysis showed that the polymorphisms of THRSPα were significantly associated with the abdominal fat weight of Jinghai Yellow chicken (P＜0.01). Multiple comparisons between different diplotypes showed that no significant differences (P＞0.05) were found in the live weight, breast muscle weight, leg muscle weight, eviscerated weight and half eviscerated weight of Jinghai Yellow chicken. However, significant differences at the level of P＜0.05 and P＜0.01 were found in the carcass weight and abdominal fat weight, respectively. In the aspect of carcass weight, H1H3 diplotype has the highest value which was significantly higher than H1H1 and H2H2 diplotypes (P＜0.05), while no significant differences were found between H1H1, H1H2 and H2H2 (P＞0.05). In terms of abdominal fat weight, H1H3 also has the highest abdominal fat weight which was significantly higher than H1H1 and H2H2 at the level of P＜0.01. The abdominal fat weight of H2H2 was the lowest which was significantly lower than any other diplotypes (P＜0.01). The results of the expression level of THRSPα in tissues revealed that the expression level of THRSPα was higher in liver and abdominal fat compared to almost no expression in heart, spleen, lung, kidney, breast muscle, leg muscle, small intestine and hypothalamus. According to the results of the expression profile, the expression of THRSPα in liver had a trend of rise first then fall with the highest expression level at 8 weeks of age and the lowest expression level at 0 week of age. However, the expression level in abdominal fat tissue was relatively stable. Comparing the expression level in these two tissues at different weeks of age, the expression level of THRSPα in liver was much higher than the expression level in abdominal fat from 4 to 12 weeks of age, while at 0 and 16 weeks of age, the expression level in liver was lower than in abdominal fat tissue. Therefore, these results further demonstrated that THRSPα was the candidate gene of chicken's carcass and abdominal fat traits. And the regulatory mechanism of THRSPα was revealed preliminarily on the fat synthesis and deposition in liver and abdominal fat.
