仙居鸡抑制素/活化素β_B亚基成熟区cDNA的克隆及序列分析

Cloning and Sequence Analysis of the Mature Inhibin/Activin β_B-subunit cDNA from Xianju Chicken

根据发表的哺乳类抑制素 /活化素 βB亚基 c DNA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βB亚基成熟区序列 ,并进行了克隆和测序。结果显示 ,鸡成熟βB亚基是由 115个氨基酸(aa)残基组成的蛋白质 ,具有 9个半胱氨酸残基 ,与发表的哺乳类相应序列对比 ,其核苷酸序列的同源性为 79.7%～82 .9%,其编码氨基酸序列的同源性为 95 .7%～ 98.3%。 βB亚基成熟区半胱氨酸残基的数目和位置与发表的哺乳类相同。说明该亚基的序列及结构在不同物种间具高度保守性 ,提示抑制素 /活化素 βB亚基可能具重要的生理功能。

The mature region of Xianju chicken inhibin/activin β B-subunit cDNA was amplified from the total RNA of follicle granulosa cells by RT-PCR using the primer pair designed according to the reported cDNA sequences of mammalian inhibin/activin β B-subunit.It was cloned and sequenced subsequently.The results revealed that the mature β B-subunit of Xianju chicken is a polypeptide of 115 amino acids containing nine cysteine residues.It is 79.7%-82.9% identical in nucleotide sequence,95.7%-98.3% identical in deduced amino acid sequence,respectively,in the mature region to the reported mammalian inhibin/activin β B-subunit cDNA clone.Its number of cysteine residues is the same,and their positions in the amino acid sequences are almost identical as compared to the mammalian inhibin/activin β B-subunit reported in GenBank,which indicates that the inhibin/activin β B-subunit is highly conserved among different species,implying an important role of inhibin/activin β B-subunit in various animals.