向日葵rRNA基因克隆及其染色体定位研究

Cloning and Physical Mapping of rRNA on Metaphase Chromosomes in Sunflower(Helianthus annuus L.)

该研究以内葵杂3号三交种为材料,采用同源序列法克隆了5S rRNA和18S rRNA基因并进行了序列测定,测得片段长度分别为515 bp和1 808 bp。以5S rRNA、18S rRNA和45S rRNA基因为探针,分别与内葵杂3号三交种染色体进行荧光原位杂交(FISH)分析。结果表明:45S rRNA和18S rRNA基因均得到3对杂交信号且位点分布相同,分别位于第3对和第10对染色体及第2对随体染色体的短臂末端;5S rRNA基因的信号位点共有2对,分布在第7对和第10对染色体短臂端部。

In this paper, 5S rRNA and 18S rRNA gene fragments were cloned from the triple hybrid of＂Inner Mongolia Hibrid oil sunflower 3＂ and their sequences were analysed. The lengths of 5S rRNA and 18S rRNA gene fragments were 515 bp and 1 808 bp, respectively. In fluorescence in situ hybridization, the probes for 5S rRNA, 18S rRNA and 45S rRNA were hybridized with sunflower genomic DNA from the triple hybrid of ＂Inner Mongolia Hibrid oil sunflower 3＂. Three pairs of hybridization signals were detected at the same loci both with 45S rRNA and 18S rRNA probes： at the end of shot arms of chromosome pairs 3, 10 and satellite chromosome pairs 2. 45S rRNA probe showed the same intensity of hybridization signals. 5S rRNA showed two pairs signals at the end of the short arms of chromosome pairs 7 and 10.