盐生草(Halogeton glomeratus)着丝粒反转录转座子及卫星DNA序列的同源克隆与分析

Homologous Cloning and Analysis of Centromeric Retrotransposons and Satellite DNA Sequences in Halogeton glomeratus

为研究藜科(Chenopodiaceae)植物盐生草(Halogeton glomeratus)着丝粒区域反转录转座子及卫星DNA序列的组成,并探讨盐生草、甜菜(Beta vulgaris L.)、藜麦(Chenopodium quinoa Willd.)这三种藜科植物着丝粒反转录转座子及卫星DNA序列的异同,本研究利用甜菜基因组中发现的着丝粒反转录转座子家族Beetle7中的LTR、Gag、RT等区段和卫星DNA序列pBv分别设计6对特异引物,以盐生草和藜麦基因组DNA为模板,利用同源克隆法获得同源序列并和原序列进行比对。结果显示,在盐生草中获得了LTR、Gag和RT三个区段的同源序列,相似性依次为91%、92%和95%,藜麦中仅存在RT同源序列,相似性为96%;仅在盐生草中获得了卫星DNA序列pBv,同源序列相似性为93%,藜麦中未获得该同源序列。由此可见,Beetle7中的LTR、Gag和RT序列存在于盐生草中,而藜麦中不存在,卫星DNA序列pBv也仅存在于盐生草中,更进一步说明藜科植物盐生草和甜菜的亲缘关系更近。

This study researched the composition of retrotransposons and satellite DNA sequences in centromere region of the Chenopodiaceae plants Halogeton glomeratus and explored similarities and differences of centromere retrotransposons and satellite DNA sequences in the three Chenopodiaceae plants(Halogeton glomeratus,Beta vulgaris L.and Chenopodium quinoa Willd.).In this study,6 pairs of specific primers were designed according to LTR,Gag,RT(which were found in Beta vulgaris L.genomes of centromeric reverse transcriptional transposon functional sequence Beetle7)and satellite DNA sequence pBv.Using genomic DNA of the Halogeton glomeratus and Chenopodium quinoa Willd.as the templates and obtaining homologous sequences by homologous cloning to compare with the original sequences.The results showed that the homologous sequences of LTR,Gag and RT were obtained in Halogeton glomeratus,and the similarity was 91%,92%and 95%,respectively.Only RT homologous sequences existed in Chenopodium quinoa Willd.,and the similarity was 96%.The satellite DNA sequence pBv also obtained homologous sequences only in Halogeton glomeratus and the similarity was 93%,but not in Chenopodium quinoa Willd.So it proves that LTR,Gag and RT sequence in the component of Beetle7 existed in Halogeton glomeratus,but not in Chenopodium quinoa Willd.,and the satellite DNA sequence pBv only existed in Halogeton glomeratus,furthermore,the relationship between Halogeton glomeratus and Beta vulgaris L.was closer.