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本文调查研究了野生稻群体内及群体间的DNA甲基化多样性。选取与亚洲栽培稻近缘的两个野生种Oryza nivara和O.rufipogon作为研究对象,采用改进的MSAP(methylation-sensitive amplification polymorphism)技术对其基因组CCGG位点的甲基化多样性进行了分析。结果表明:在同一个IRGC(the International Rice Germplasm Center)编号群体内的不同个体间,基因组甲基化条带高度一致;而在不同编号群体间,甲基化条带表现为多态。其中后者又可以分为两类:条带模式高度一致的Class I和条带模式呈多态性的Class II。将上述两类甲基化片段的编码基因与栽培稻粳稻(O.sativa L.subsp.japonica)和籼稻(O.sativa L.subsp.indica)两个亚种的同源基因进行序列比对发现,在进化趋势上Class I表现得比较保守,而Class II较为活跃。DNA甲基化多样性作为标志遗传多样性的一种信息来源,其在群体分化及物种进化过程中的作用还需要进一步探讨。
This paper investigates the DNA methylation diversity in and between wild rice populations. Two wild species Oryza nivara and O. rufipogon, which are closely related to cultivated rice in Asia, were selected as the research objects. The methylation-sensitive amplification polymorphism (MSAP) was used to analyze the methylation diversity of CCGG locus. The results showed that the genomic methylation bands were highly consistent among different individuals in the same IRGC numbering population, while the methylation bands were polymorphic in different numbering populations. Thereinto, the latter can be divided into two categories: Class I with highly consistent banding patterns and Class II with polymorphic patterns. The sequence alignment of the genes encoding the above two types of methylation fragments with the homologous genes of two subspecies of O. sativa L. subsub. Japonica and O. indica L. subsp.indica was found Class I is more conservative in evolutionary trends and Class II is more active. DNA methylation diversity as a marker of genetic diversity as a source of information, its role in population differentiation and species evolution needs further study.