中文摘要：

为从比较基因组学角度研究鸭、鸡甲状腺激素应答Spot14alpha（THRSPα）基因突变的异同,根据对鸭THRSPα基因克隆和表达的研究结果,采用多样本PCR产物测序方法筛查鸭THRSPα基因编码区和部分内含子区的核苷酸变异,并与已知的鸡THRSPα基因编码区多态进行比较分析。结果表明：鸭THRSPα基因突变频率远高于鸡,编码区平均突变频率为每1000个碱基有23个碱基发生突变,内含子区平均每1000个碱基有28个碱基发生突变。编码区16个突变有3个为错义突变,其余均为同义突变。并且THRSPα蛋白靠近亮氨酸拉链结构域N端的第81位天冬氨酸（Asp81）,在鸭中错义替换为缬氨酸（Val）,在鸡中发生插入或缺失。提示鸭在进化过程中所受选择程度低于鸡,使其THRSPα基因碱基替换频率和分布均匀度均高于鸡,二者在脂肪性状相关的Asp81位点处均发生缺失或突变。

英文摘要：

To explore the mutation characteristic of the duck thyroid hormone responsive spot 14 alpha （THRSPα） gene cloned by the authors, the various PCR products covering the coding or intron regions of this gene were sequenced directly. The results showed that there was 23 single nucleotide polymorphisms （SNPs） per 1 000 nucleotides in the coding region compared to 28 SNPs per 1 000 nucleotides in intron region. The variations in the coding region contained three non-synonymous mutations and thirteen synonymous mutations. Furthermore, the 81th Aspartate （Asp81） was substituted to Valine near the N terminus of the leucine zipper domain of the duck THRSPα peptide, in contrast with the insertion/ deletion （indel） of the Aspartate in the same site of the chicken THRSPα. The study implicated that the less selective pressure made the duck THRSPα gene keep more frequent and balanced variations than that of the chicken counterpart during the course of bird domestication. The deeper exploration was necessary whether the non-synonymous substitution of the Asp81 locus for THRSPα gene was associated with fatness traits of the ducks.