中国农业科学 ›› 2008, Vol. 41 ›› Issue (7): 2120-2127 .doi: 10.3864/j.issn.0578-1752.2008.07.033

• 畜牧·资源昆虫 • 上一篇    下一篇

猪Cystatin B基因cDNA克隆及遗传多态性分析

陈 磊,李学伟,朱 砺,李 强,李明洲   

  1. 四川农业大学动物科技学院
  • 收稿日期:2007-05-08 修回日期:2007-08-09 出版日期:2008-07-10 发布日期:2008-07-10
  • 通讯作者: 李学伟

Cloning, Characterization and Polymorphism of the Porcine (Sus Scrofa) Cystatin B Gene

  

  1. 四川农业大学动物科技学院
  • Received:2007-05-08 Revised:2007-08-09 Online:2008-07-10 Published:2008-07-10

摘要: 【目的】研究猪肉嫩度性状候选基因-半胱氨酸蛋白酶抑制素B(Cystatin B,CSTB)基因对肌肉宰后嫩化的作用,为研究嫩度性状的遗传机理提供理论基础。【方法】采用RT-PCR结合克隆测序的方法,从猪肌肉组织总RNA中克隆到猪CSTB基因cDNA序列,并推导出其编码的氨基酸序列。采用PCR-RFLP方法,分析了84头猪CSTB基因多态性及其与嫩度性状的关联性。【结果】CSTB基因开放阅读框全长294 bp,编码98个氨基酸。同源性分析结果表明,猪与人、鼠、牛的CSTB基因cDNA编码区(CDS)同源性分别为81%、85%和89%,推测氨基酸序列同源性为83%、76%和85%。蛋白质结构同源建模分析表明,该蛋白与人、鼠Cystatin B类似,具有stefin类蛋白酶抑制剂的典型空间结构,包括5条平行的β-sheet和负责与被抑制酶结合的楔形边缘。在CSTB基因第二内含子内PvuⅡ酶切位点检测到了AA、AB和BB这3种基因型,关联性分析表明AA基因型个体的各项嫩度指标均极显著低于另2种基因型的个体(P<0.01),最大剪切力为5.11 kg,硬度值为19.31 kg•s、平均剪切力为3.26 kg。【结论】CSTB基因在不同物种间具有较高同源性,猪CSTB基因多态性与猪肉嫩度性状显著相关。

关键词: 猪, Cystatin B基因, 基因克隆, 嫩度

Abstract: Utilizing technique of RT-PCR and sequencing, the nucleotide and deduced amino acid sequence of the porcine cystatin B (CSTB) gene were obtained in this study. The open reading frames (ORFs) of the CSTB gene were 294bp long (encoding for 98 amino acids). The nucleotide sequence identities of porcine CSTB Complete Coding Sequence (CDS) were 81%, 85% and 89% compare to that of the human, rat, and bovine CSTB CDS respectively. The deduced amino acid sequence identities of the porcine CSTB protein were 83%, 76%, and 85% compare to that of the rat, human, and bovine CSTB proteins, respectively. The structure of CSTB protein was predicted by homologous modelling which was similar to the results observed previously in humans and mouse. The five-stranded antiparallel β-sheet and the wedge shaped edge were found in the structure model. The polymorphisms of porcine CSTB gene was detected in 84 pigs by PCR-RFLP. Base on the polymorphism detection, the influence of CSTB genotype on tenderness traits were analyzed. The genotype AA in CSTB gene PvuII locus had significantly lower Shear force (5.11 kg), Toughness (19.31 kg.s) and Mean Shear force (3.26 kg) than genotype AB and BB (P<0.01).

Key words: pigs, cystatin B gene, gene cloning, tenderness