摘要：
甲状腺激素应答蛋白Spot 14(thyriod hormone responsive spot 14,THRSP)是一个参与调控脂肪生成酶活性进而影响动物组织中脂类代谢的转录调控因子,THRSP基因包括α和β两种亚型.为了探究THRSPα基因与京海黄鸡(Gallus gallus)屠体和腹脂性状相关性,并分析其组织表达特性和表达规律,本研究运用聚合酶链式反应-单链构象多态性(polymerase chain reaction-single strand conformation polymorphism,PCR-SSCP)结合测序技术研究该基因的多态性,并通过qRT-PCR技术研究该基因在10种组织中的表达情况以及0～16周龄的表达规律.结果表明,THRSPα基因外显子2序列中存在C129T和T160G两处突变,且在京海黄鸡群体中形成3种单倍型和5种单倍型组合.不同单倍型组合间屠体重和腹脂重差异显著和极显著(P＜0.05和P＜0.01),其中单倍型组合为H1H3的个体,其屠体重和腹脂重均显著和极显著高于单倍型组合为H1H1和H2H2的个体(P＜ 0.05和P＜0.01),单倍型组合H2H2腹脂重极显著低于其他各单倍型组合(P＜0.01).THRSPα基因的组织表达谱分析显示,THRSPα基因在肝脏和腹脂中的表达量显著和极显著高于其他组织(P＜0.05和P＜0.01);THRSPα基因的表达规律研究结果发现,THRSPα基因在肝脏中的表达规律呈先升高后下降趋势,8周龄时表达水平最高,THRSPα基因在腹脂中表达水平相对稳定.本研究进一步证明了THRSPα基因为鸡屠体和腹脂性状的候选基因,为进一步研究THRSPα基因对鸡肝脏脂肪合成和腹脂沉积的调控机理提供了参考.%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 β3 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 THRSPoα 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.
