大麦45S和5SrDNA定位及5SrDNA伸展纤维的FISH分析

Location of 45S and 5S rDNA on Barley Chromosomes and FISH Analysis for 5S rDNA on Extended DNA Fibers

摘要: 用荧光原位杂交技术对45S和5SrDNA在大麦(Hordeum vulgare L.)有丝分裂中期染色体进行了确定分析,较强的45SrDNA信号共有2对,分别分布在大麦的第1染色体的短臂和第2染色体的长臂。而5SrDNA则只有1对杂交信号,位于第3染色体的长臂,但信号较弱。用伸展DNA纤维的荧光原位杂交(Fiber-FISH)技术测定了5SrDNA在大麦的基因组中的拷贝数,计算出5SrDNA的拷贝数约为408～416。对大麦品种中rDNA位点数目的可变性进行了讨论。

Abstract: With the help of fluorescene in situ hybridization(FISH),we have located and analyzed the sites of the 45S and 5S rDNA on the mitotic metaphase chromosomes of barley (Hordeum vulgare L.).The results indicated that there were two pairs of signs detected for 45S rDNA,each at 1S and 2L.The signal of 5S rDNA was relatively weak,and it was located on 3L.The copy number of 5S rDNA was determined by extended DNA fiber based on DNA fiber fluorescence in situ hybridization (Fiber-FISH) in barley genome.It could be estimated that the copy number was about 408-416 for 5S rDNA.In this study,the variability of number of rDNA in genome among different barley species was discussed.