新疆褐牛与荷斯坦牛NF-κB基因表达与TOLL样受体4基因型的关系

The Relationship of Toll-Like Receptor Genotype with NF-κB Gene Expression in Xinjiang Brown Battle and Holstein

核转录因子NF-κB与动物机体的炎症反应、免疫应答、细胞分化和凋亡等密切相关,而Toll样受体(TLR)通过对侵入机体的病原微生物的抗原识别和信号转导,在NF-κB介导的炎症和免疫应答反应中发挥着重要作用。本研究在新疆褐牛和荷斯坦牛隐性乳房炎调查和TLR4外显子3+2021位点(E3+2021)SNP基因型与隐性乳房炎相关性研究的基础上,分析和比较了E3+2021 SNP位点3种不同基因型奶牛个体NF-κB信号通路上9个基因(NFκB1、NFκB2、RelA、c-Rel、RelB、IKKα、IKKβ、IKKγ和IκBα基因)转录水平的差异。结果显示,在BB基因型中,NFκB1和IKKα基因的mRNA转录水平在新疆褐牛与荷斯坦牛品种间差异显著(P<0.05),RelA、RelB、IKKβ、IKKγ和IκBα基因mRNA转录水平在品种间差异极显著(P<0.01)。在AB基因型中,IκBα基因mRNA转录水平在品种间差异显著(P<0.05)。在对新疆褐牛的研究中发现,RelB、IKKγ和IκBα基因mRNA转录水平在AB和BB两种基因型间差异显著(P<0.05);而在荷斯坦牛检测的9个基因的mRNA转录水平在AB和BB两种基因型间差异均不显著。因此,Toll样受体信号转导通路下游NFκB1、RelA、IKKβ、IKKγ和IκBα基因的mRNA转录水平在品种间的变化,可能与新疆褐牛乳汁中体细胞数(SCS)显著低于荷斯坦牛相关。在新疆褐牛中,RelB、IKKγ和IκBα基因mRNA转录水平的变化可能是AA基因型SCS显著高于AB基因型的原因之一。

Nuclear factor-κB（NF-κB） has close association with inflammation,immune response,differentiation and apoptosis.In the NF-κB passway,TLRs play an important role in the process of inflammatioin and immune response through the function of pathogen recognition and signal transduction.Underlying our previous investigations on the subclinical cow mastitis between Xinjiang brown cattle and Chinese Holstein and correlation of TLR4 E3＋2021 genotype with subclinical mastitis,we measured the transcriptional level of nine major genes（NFκB1,NFκB2,RelA,c-Rel,RelB,IKKα,IKKβ,IKKγ,IκBα） of the NF-κB passway among three genotyping groups of AA,AB and BB.The results showed that the transcriptional level of NFκB1 and IKKα were significantly different（P〈0.05） and RelA,RelB,IKKβ,IKKγ and IκBα were extremely significantly different（P0.01） between Chinese Holstein and Xinjiang brown cattle in the BB genotype.The transcriptional level of IκBα were significantly different（P〈0.05） between two breeds in AB genotype.In the studies on Xinjiang brown cattle,we observed that the transcripts of AB genotype of RelB,IKKγ and IκBα were significantly higher than those of BB genotype（P〈0.05）.While the transcriptional levels of the nine genes between AB and BB genotype were no significantly different in Chinese Holstein.Taken together,the variation of the mRNA transcriptional levels of NFκB1,RelA,IKKβ,IKKγ and IκBα between Xinjiang brown cattle and Chinese Holstein was probably associated with the different mastitis incidence intwo breeds.Moreover the high transcriptional levels of RelB,IKKγ,IκBα may be one of the causal to the low SCS in AA genotype in Xinjiang brown battle.