仙居鸡抑制素/活化素β_A亚基成熟区的cDNA克隆及序列分析

cDNA Cloning and Sequence Analysis of the Mature Inhibin/Activin β_A Subunit from Xianju Chicken

本研究根据发表的来航鸡抑制素 /活化素βA 亚基序列设计引物 ,运用RT PCR技术从仙居鸡卵泡的颗粒细胞总RNA中扩增出抑制素 /活化素βA 亚基成熟区序列 ,并进行了克隆和测序。结果显示 ,所测鸡成熟βA 亚基是由 116个氨基酸 (aa)残基组成的蛋白质 ,共有 9个半胱氨酸残基 ,与发表的鸡及哺乳类相应序列对比 ,其核苷酸序列的同源性分别为 99.2 %和 81%～ 85 .2 % ,其预测氨基酸序列的同源性分别为 10 0 %和 96 .6 %～ 97.4 % ,且所测鸡 βA 亚基成熟区半胱氨酸残基的数目和位置与发表的鸡和哺乳类相同 ,说明该亚基的序列及结构在不同物种间具高度保守性 。

The mature region of Xianju chicken inhibin/activin β A subunit was amplified from the total RNA of follicle granulosa cells by RT PCR using the primer pair designed according to the reported cDNA sequence of Leghorn chicken inhibin/activin β A subunit, and this fragment of β A subunit was cloned and sequenced subsequently. The results reveal that the mature β A subunit of Xianju chicken is a fragment of 116 amino acids containing nine cysteine residues. It is 99.2% and 81%～85.2% identical in nucleotide sequence, 100%and 96.6%～97.4% identical in deduced amino acid sequence, respectively, in the mature region to the reported chicken and mammalian inhibin/activin β A subunit cDNA clone. As for the mature inhibin/activin β A subunit, the number of cysteine residues is the same, and their positions in the amino acid sequences are almost identical as compared to the chicken and mammalian inhibin/activin β A subunit reported in GenBank, which indicates that the inhibin/activin β A subuntit is highly conserved among different species, implying an important role of inhibin/activin β A subunit in various animals.