文章采用PCR-SSCP方法对亚洲野猪、3个引进的商业化品种和10个中国地方猪品种共893个个体TLR4 基因外显子1的遗传变异进行了检测, 旨在系统分析国内外猪种TLR4基因的多态性, 为探讨该基因在免疫和防御系统中发挥的作用提供依据。结果, 在猪TLR4基因外显子1中分离到新的等位基因, 共检测到3个等位基因, 6种基因型。其中杜洛克检测到AA、BB、CC、AB、AC、BC基因型, 有杜洛克血统的苏太猪中检测到BB、CC、BC基因型, 长白猪、约克夏中检测到CC、BC基因型, 野猪及所有10个中国地方猪品种TLR4基因外显子1高度保守, 只检测到CC基因型, 中国地方猪品种和引进品种TLR4基因外显子1多态性存在极显著的差异。3种基因型中CC 型与GenBank中的序列一致, BB和AA基因型分别存在G93C同义突变位点和G194A无义突变位点, 这2个变异位点与抗逆性和一般抗病力的关系值得进一步深入研究。
Using the PCR-SSCP method, the genetic variation in exon 1 of the TLR4 gene was detected among 893 animals, including Asian wild boars, 3 imported commercial and 10 Chinese indigenous swine breeds. This was conducted to analyze the polymorphisms of exon 1 of TLR4 gene in native and foreign pig breeds and aimed at providing a theoretical foundation for further research on the role that TLR4 gene played in immune and defense system. New alleles were isolated for exon 1 of the swine TLR4 gene for the first time, There were 6 genotypes and 3 alleles, in which the Duroc appeared AA, BB, CC, AB, AC and BC genotypes; Sutai pig, which has Duroc pig origin, were detected to be BB, CC, and BC genotypes; Yorkshire and Landrace were detected to be CC and BC genotypes. Wild boar and all 10 Chinese native pig breeds appeared highly conserved in exon 1 of TLR4 gene, with only CC genotype. Among the 3 homozygous genotypes, the CC genotype matches the sequence in GenBank, while a G93C synonymous mutation and a G194A nonsense mutation were found in the BB and AA genotypes, respectively. The correlation between these two mututation points of TLR4 gene with resistance to stress and disease is worthy of further study.
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