Analysis of genome DNA methylation level in Rongchang Pigs | 荣昌猪基因组DNA甲基化水平分析

Chinese. 探讨荣昌猪基因组DNA甲基化水平随生长发育阶段和组织类型不同而变异的规律。采用HPLC法分别检测了荣昌猪阉公猪心脏、肝脏、半膜肌3种组织在10，20，35，50，80和100 kg体质量阶段基因组DNA的甲基化水平,分别以体质量和组织类型为影响因素进行单因素方差分析。与10 kg体质量阶段的基因组DNA甲基化水平相比，3种组织基因组DNA甲基化水平均随个体体质量的增加而呈下降趋势，但不同组织下降的幅度不同：心脏基因组DNA甲基化水平在35 kg时开始明显下降（P＜0.01)，到100 kg时下降了44.00%；肝脏基因组DNA甲基化水平在80 kg时开始明显下降（P＜0.05)，到100 kg时下降了26.06%；半膜肌基因组DNA甲基化水平在20 kg时开始明显下降（P＜0.01)，到100 kg时下降了60.78%。半膜肌的基因组DNA甲基化水平在10 kg体质量阶段显著高于心脏(P＜0.05)，极显著高于肝脏(P＜0.01)，在 20 kg体质量阶段极显著低于心脏和肝脏 (P＜0.01)； 肝脏的基因组DNA甲基化水平在35 kg体质量阶段显著高于半膜肌(P＜0.05)，在 50和80 kg体质量阶段极显著高于心脏和半膜肌(P＜0.01)，在100 kg体质量阶段显著高于心脏(P＜0.05),极显著高于半膜肌(P＜0.01)。体质量阶段是猪基因组DNA甲基化水平的重要影响因素之一。DNA甲基化水平在肝脏与半膜肌间具有组织特异性，而在心脏与肝脏间、心脏与半膜肌间是否具有组织特异性与体质量阶段明显相关。

English. The objective of this study was to explore the variations of DNA methylation level among different development stages and different tissues in Rongchang pigs. 5-methylcytosine contents of heart, liver and semimembranosus tissues genomic DNA of Rongchang Pigs, among 6 different live weight stages including 10, 20, 35, 50, 80 and 100 kg were separately detected by high performance liquild chromatography (HPLC) in this study. One-factor analysis of variance was employed independently using live weight and tissues as factor. Compared with that at 10 kg live weight stage in heart, liver and semimembranosus tissues, different degrees of genomic DNA methylation levels decreased in different tissues with increasing individual live weight. In heart, genomic DNA methylation extremely significantly decreased at 35 kg live weight, and it dropped by around 44.00% at 100 kg live weight. In liver, genomic DNA methylation significantly decreased at 80 kg live weight, and it dropped by around 26.06% at 100 kg live weight. In semimembranosus,genomic DNA methylation extremely significantly decreased at 20 kg live weight,and it dropped by around 60.78% at 100 kg live weight. At 10 kg live weight, DNA methylation level in semimembranosus tissues was higher than that in heart (P＜0.05) and significantly higher than that in liver (P＜0.01). At 20 kg live weight, the level in semimembranosus tissues was significantly lower than heart and liver (P＜0.01). At 35 kg live weight, DNA methylation level in liver was higher than that in semimembranosus (P＜0.05). At 50 and 80 kg live weight stage, DNA methylation level in liver was significantly higher than that in heart and semimembranosus (P＜0.01). At 100 kg live weight, DNA methylation level in liver was higher than that in heart (P＜0.05) and significantly higher than that in semimembranosus (P＜0.01). Live weight is one of the important factors which affect genomic DNA methylation state of pigs. DNA methylation pattern of liver and semimembranosus is shown of tissue specificity. And the specific genomic DNA methylation patterns of heart and semimembranosus, heart and liver are associated with the individual live weight.