性成熟前猪睾丸组织中印记基因DNA甲基化状态分析

摘要

为探求性成熟前猪睾丸中印记基因DNA甲基化状态,以1、2、3月龄三元杂交猪睾丸实质组织为材料,在利用MeDIP-seq(甲基化DNA免疫沉淀测序技术)建立性成熟前猪睾丸全基因组DNA甲基化图谱的基础上,比对得到了8个已证实的猪印记基因甲基化状态.结果显示,8个印记基因DIRAS3、IGF2、IGF2R、MEST、NAP1L5、NNAT、PEG10、PLAGL1,在性成熟前猪睾丸组织中的甲基化水平均不高,表现为"非甲基化"或"部分甲基化";NNAT、PLAGL1启动子甲基化水平在1~3月龄间保持增长,NAP1L5、IGF2R启动子甲基化水平在1~2月龄下降,2~3月龄增长,DIRAS3、IGF2、MEST、PEG10 promoter甲基化水平在1~2月龄增长,2~3月龄下降;图谱中仅比对到4个基因的gene body甲基化状态,IGF2R、MEST gene body甲基化水平在1~3月龄保持下降,PLAGL1、PEG10 gene body甲基化水平在1~2月龄增长,2~3月龄下降.推测这8个印记基因在性成熟前猪睾丸发育过程中均具有一定活性,且DNA甲基化对印记基因发挥一定的调控作用.%To determine the DNA methylation status of imprinted genes in the prepubertal porcine testis, we chose the testis tissues of 1, 2 and 3 months old pigs, and detected the methylation levels of eight imprinted porcine genes on the basis of the genome-wide DNA methylation profile of prepubertal porcine testis, using the method of MeDIP-seq.The results demonstrated that DIRAS3, IGF2, IGF2R, MEST, NAP1L5, NNAT, PEG10 and PLAGL1, all these eight imprinted genes showed low methylation levels with "unmethylated" or "partially methylated" status.The methylation levels of NNAT and PLAGL1 promoters increased from one month old (T1) to three months old (T3);the methylation levels of NAP1L5 and IGF2R promoters decreased from T1 to two months old (T2) but increased from T2 to T3;while the methylation levels of DIRAS3, IGF2, MEST and PEG10 promoters increased from T1 to T2 but decreased from T2 to T3.Besides, we only aligned 4 gene bodies from the methylation profile, and the methylation levels of IGF2R and MEST gene bodies decreased from T1 to T3, while the methylation levels of PLAGL1 and PEG10 gene bodies increased from T1 to T2 but decreased from T2 to T3.It can be postulated from the results that these eight imprinted genes may be active during the development of prepubertal porcine testis, and DNA methylation may play a role in regulation of imprinted genes.