一种高等植物小片段RNA分子标记方法

Short RNAs,potential novel molecular markers for higher plants

分子生物学技术特别是分子标记方法越来越多应用于研究植物间相似关系及其进化规律。为试图寻找一种适合缺乏分子生物学数据的,以及能够在属以上高阶元间快速比较研究的小片段RNA分子标记方法,作者通过含HAc-NaAc缓冲体系的SDS总核酸提取方法,提取了53种高等植物的总核酸。将总核酸在7%的聚丙烯酰胺凝胶中电泳,结果发现:(1)在100-200 bases的位置有高丰度的RNA条带,条带稳定清晰,结果可重复再现,用DNaseI和RNaseA处理后认为这些片段属于小片段RNA。(2)比较了绿豆幼苗经0-8h不同光照处理,以及猕猴桃不同品种和器官之间的小片段RNA,表明不同光照时间、不同性别的花蕾、叶片和染色体倍性间的带型一致,说明这些片段部分具有一定的空间结构,其表达极其稳定,无明显差异。(3)同一科内的植物的带型存在多态性,主要是由地理隔绝造成的差异,并且分类阶元高的多态性百分比和多态性信息量高于分类阶元低的。(4)经过比较蕨类植物、裸子植物和被子植物53种植物的小片段RNA,发现在100-200bases中含3-6条清晰的条带,带型跟植物亲缘关系相关。因此,作者认为100-200bases位置的小片段RNA可作为鉴定植物科间和科内亲缘关系的一种分子辅助标记。

In recent years,molecular biology techniques,especially molecular markers,have been applied to the study of species similarity and evolutionary relationships in the field of plant systematics.Here,we attempted to find a small fragment of RNA that could be used as a molecular marker for the rapid identification of plant taxa above genus.To do so,total nucleic acids were isolated from 53 species of higher plants using SDS extracting solution containing HAc-NaAc buffer.The isolated nucleic acids were subjected to 7% polyacrylamide gel electrophoresis（PAGE）.Results showed：（1） A large number of bands,which were at the length of 100-200 bases and with clear shape.The bands patterns were stable and repeatable.These segments were confirmed to be short RNAs by DNaseI and RNaseA treatment;（2） No obvious differences in band patterns were found among different varieties,organs,sexualities and ploidy of kiwifruit seedlings.A similar case existed in mung bean seedlings after different light treatment periods;（3） Banding patterns of plants in the same family were polymorphic,with differences mainly related to geographic isolation.Higher taxonomic categories had a higher percentage of polymorphic band（PPB） and higher values of polymorphism information content（PIC） than lower taxonomic categories;（4） Three to six clear bands with a length of 100-200 bases,whose band patterns were related to the phylogenic relationship,were found through comparison of short RNAs from 53 species of ferns,gymnosperms and angiosperms.Thus,short RNAs with a length of 100-200 bases showed potential as a molecular marker for determining inter-or intrafamily phylogenic relationships.