羊驼垂体催乳素（PRL）基因全长cDNA的克隆及序列分析

[目的]获得并分析羊驼PRL基因cDNA全序列结构，为研究羊驼催乳素（PRL）的各种生物学作用和生产应用提供理论依据。[方法]根据已知的不同哺乳动物的PRL基因cDNA序列，设计羊驼PRL引物，运用RT-PCR方法和cDNA末端快速扩增（RACE）技术获得羊驼PRL基因cDNA全序列。[结果与结论]羊驼PRL基因cDNA序列全长959bp，编码区为687bp，编码229个氨基酸的PRL前体蛋白。预测羊驼PRL蛋白质的空间结构类似人生长激素（GH），但在81位（成熟肽为51位）为蛋氨酸可能导致蛋白空间结构的不同而影响羊驼PRL的功能；序列比对结果表明，羊驼PRL的 cDNA序列与大多数哺乳动物相似。构建的基因进化树分析结果显示，羊驼PRL与骆驼的亲缘关系最近；同多数哺乳动物一样，羊驼PRL进化速度极缓慢，没有发生人、灵长类、啮齿类、反刍动物的“episodic”式进化。

Cloning and Sequence Analysis of the Full-length cDNA of PRL Gene from Alpaca Pituitary

In order to provide theoretical basis for studying biological function and application of alpaca prolactin ( PRL ), the alpaca PRL cDNA sequence were cloned and analyzed. According to the known cDNA sequences from mammals, alpaca PRL primers was designed and the full-length cDNA of PRL from alpaca pituitary was cloned by RT-PCR and RACE techniques. The size of full-length cDNA of PRL from alpaca pituitary was 959 bp and it contained an open reading frame (ORF) of 687 bp which encoded PRL precursor protein w...