不同地理群体三疣梭子蟹mtDNA本底甲基化水平分析

Analysis of methylation profile level in the background for the blue swimming crab Portunus trituberculatus of different geographical populations

利用重亚硫酸盐测序法,对适于三疣梭子蟹(Portunus trituberculatus)线粒体基因组甲基化分析的BSP(Bisulfite sequencing PCR)引物进行了筛选,在设计的21对引物中,获得了12对BSP引物。利用这12对引物分析了三疣梭子蟹海州湾群体(江苏连云港)和莱州湾群体(山东东营)线粒体基因组本底甲基化水平,结果表明:海州湾群体不存在甲基化现象,莱州湾群体发现了2个个体在ND2基因(NADH脱氢酶亚基2)位点存在甲基化现象;在存在甲基化的个体中,甲基化类型主要为CHG和CHH类型,还有少量Cp G类型。该研究结果说明,莱州湾群体和海州湾群体线粒体基因组本底水平上的甲基化特征存在一定差异,相关研究值得进一步深入探讨。

For the high scientific and commercial value,the protection and utilization of germplasm resource of the blue swimming crab,Portunus trituberculatus,has attracted more and more attentions in past decades.The blue swimming crab is widely distributed in the coastal areas along the Bohai Sea,the Yellow Sea,the East China Sea and the South China Sea. Previous studies showed that the wild population located in Laizhou bay of Bohai Sea was different from the other populations,and only obseved in the Laizhou bay. The evidences supporting the conclusions above mainly came from the comparative analysis of nuclear DNA and mt DNA sequences among different populations. To obtain more evidences,the genetic differences between Laizhou bay population and other populations were compared at the level of epigenetics. Based on the Bisulphite Sequencing,the BSP（ Bisulfite sequencing PCR） primer pairs of mt DNA were screened in P.trituberculatus. In the designed 21 primer pairs,twelve were useful for analyzing the methylation profiles of mt DNA. Then the methylation background levels of two geographical populations,Haizhou bay（ Lianyungang of Jiangsu province） and Laizhou bay（ Dongying of Shandong province） were clarified by the 12 primer pairs.The results showed that no methylation phenomenon was found in Haizhou bay population,while 2 individuals with methylation were found in the Laizhou bay population. The methylation sites were located in the gene of ND2. Excluding few Cp G type,the main methylation types in the methylated individuals were CHG and CHH（ H is A,C or T）. The findings provide further evidences for proving that the Laizhou bay population is different from the Haizhou bay population.