| 摘要: |
| 【目的】 研究牛Toll样受体蛋白2基因（TLR2）的多态性及其与中国荷斯坦奶牛乳房炎的关系。【方法】 以中国荷斯坦奶牛、鲁西黄牛和渤海黑牛为研究对象，利用DNA测序、PCR-RFLP和创造酶切位点RFLP(CRS-RFLP)技术对TLR2基因多态性及其与中国荷斯坦奶牛乳房炎的关系进行研究。【结果】 经DNA测序，在牛TLR2基因的3′非翻译区发现1个新的SNP，即mRNA序列的3 008位发生了T/C突变。TLR2基因编码区(c.651G>A,c.827A>G)和3′非翻译区(c.3008T>C)有3个突变位点，分别是Pst I，Hin1 Ⅱ和Hha I限制性内切酶的酶切多态位点。3个多态位点在各品种牛之间的基因型频率和等位基因频率差异较大；经χ2适合性检验，除鲁西黄牛的Hha I酶切位点处于非Hardy-Weinberg平衡状态外，3种牛在其他位点均处于Hardy-Weinberg平衡状态(P＞0.05)。只有Hin1 Ⅱ酶切多态位点与牛乳中的体细胞评分(SCS)存在相关性，含有B等位基因的个体SCS显著低于含有A等位基因的个体(P<0.05)。中国荷斯坦奶牛在3个酶切位点形成了H1-H8共8种单倍型，产生了H1H1、H1H2、H1H3、H1H4、H1H7和H1H8等6种单倍型组合，其中H1H1的频率最高(55.89%)，H1H4的SCS最低(3.17)，且不同单倍型组合与SCS存在相关性。【结论】 TLR2基因可用作奶牛抗乳房炎性状的辅助选择标记。 |
| 关键词: 牛 乳房炎 TLR2基因 体细胞评分 单倍型 |
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| 基金项目:科技部“863”计划项目( 2006AA10Z1D9)；山东省农业科学院青年基金项目(2006YQN030) |
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| The relationship between polymorphism of TLR2 gene and mastitis in dairy cattle |
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| Abstract: |
| 【Obiective】 The polymorphism of TLR2 gene was studied and its association with mastitis in Chinese Holstein was analyzed.【Method】 Three bovine breeds,including Chinese Holstein(331),Luxi cattle(66)and Bohai Black cattle(30),were used as experimental examples by direct sequencing,PCR-RFLP and CRS-PCR methods.【Result】 One new single nucleotide polymorphism,SNP(c.3008T>C),was identified in the 3′-untranslating region of TLR2 gene by direct sequencing.Two SNPs (c.651G>A and c.827A>G)and new SNP (c.3008T>C) corresponded to restriction endonuclease Pst I,Hin1Ⅱand Hha I.The genotype frequencies and allele frequencies had a large difference among the three bovine breeds.Statistical result of χ2 test indicated that the three polymorphic sites reached Hardy-Weinberg equilibrium (P>0.05) except for Hha I polymorphism in Luxi cattle.The association was observed between genotypes or haplotypes and SCS in there restriction enzymes polymorphic sites in Chinese Holstein.The results indicated that the cattle with allele B in Hin1Ⅱ showed lower SCS than that of allele A (P<0.05).Eight haplotypes including H1～H8 and six haplotype combinations including H1H1,H1H2,H1H3,H1H4,H1H7,H1H8 were detected.The frequency of H1H1 was the highest(55.89%)and the SCS of H1H4 the lowest(3.17),among 6 haplotype combinations.The correlation was detected between different haplotype combinations and SCS.【Conclusion】 The results indicated TLR2 gene could be used as the molecular genetic marker to select the mastitis resistance in cow. |
| Key words: cattle mastitis TLR2 gene SCS haplotype |
