Gan J K, Zhang D X, He D L, Zhang X Q, Chen Z Y, Luo Q B
Department of Animal Genetics, Breeding and Reproduction, College of Animal Science, South China Agricultural University, Guangzhou, Guangdong, China.
Genet Mol Res. 2013 Mar 15;12(1):809-19. doi: 10.4238/2013.March.15.1.
DNA methylation plays a central role in gene expression. In this study, we detected the promoter methylation pattern of the chicken heat shock protein 70 (HSP70) gene and its association with messenger RNA (mRNA) expression before and after heat shock. The results showed that mRNA expression increased in response to heat stress and peaked at 3 h before dropping. Hypomethylation of the HSP70 promoter occurred in all of the groups studied, but the difference between groups within tissue type was not significant. The DNA methylation level of the control and the 6-h treatment groups was slightly higher than that of the 3-h treatment group in brain tissue and leg muscle. Correlation analysis between mRNA expression and DNA methylation of HSP70 showed that DNA methylation was negatively associated with mRNA expression in leg muscle (P = 0.0124), indicating that DNA methylation may be negatively associated with the expression of HSP70, although the difference was not significant. We concluded that the expression of HSP70 is heat inducible and tissue dependent and that heat induction may correlate with DNA methylation pattern in the HSP70 promoter, whereas tissue dependence is unrelated to DNA methylation pattern.
DNA甲基化在基因表达中起着核心作用。在本研究中，我们检测了鸡热休克蛋白70（HSP70）基因的启动子甲基化模式及其与热休克前后信使核糖核酸（mRNA）表达的关联。结果显示，mRNA表达随热应激而增加，并在3小时达到峰值，随后下降。在所研究的所有组中均出现了HSP70启动子的低甲基化，但组织类型内各实验组之间的差异并不显著。在脑组织和腿部肌肉中，对照组和6小时处理组的DNA甲基化水平略高于3小时处理组。HSP70的mRNA表达与DNA甲基化之间的相关性分析表明，腿部肌肉中的DNA甲基化与mRNA表达呈负相关（P = 0.0124），这表明DNA甲基化可能与HSP70的表达呈负相关，尽管差异并不显著。我们得出结论，HSP70的表达是热诱导性的且具有组织依赖性，热诱导可能与HSP70启动子中的DNA甲基化模式相关，而组织依赖性与DNA甲基化模式无关。
