摘要
参考国内外有关文献，综述了应用荧光原位杂交技术对45S和5SrDNA在果树染色体上的比较定位以及rDNA特异序列在果树系统进化研究中的应用现状，并指出其在果树应用中存在的问题和未来的发展现状。研究表明．果树的45SrDNA位点一般为1～4对，在染色体上多定位于随体处（即核仁组织区，NORs），也常分布于短臂和着丝粒区：5SrDNA为1～3对，在染色体上没有固定的分布模式，且与45SrDNA独立分布。rDNA定位已经用于识别果树染色体，校正传统核型以及研究基因组的进化模式。ITS序列是目前果树系统研究中应用最广泛的序列之一，但应用时需要检验是否存在假基因，未来的关注点应是综合运用多种DNA序列。
The research progress on physical mapping to chromosome and phylogenetic inference of 45S and 5S rDNA in fruit trees were reviewed in the paper, and their limitation and promising application prospect were also summarized at the end. Studies have shown that the loci of 45S and 5S rDNA on chro- mosome were independent from each other. By fluorescence in situ hybridization （FISH）, 45S rDNA re- peats, ranging from 1 to 4 pairs in fruit trees, were found to usually locate on distal satellites, short arm as well as centromere of chromosome. While the 5S repeats, ranging from 1 to 3 pairs, had no fixed loci on chromosomes. The number and location of rDNA loci have been used widely in identifying chromosomes, revising traditional karyotype and genome revolution in tree fruits. At the same time, internal transcribed spacer （ITS）, one of specific rDNA sequences, had been applied widely in phylogenetic restruction in fruit trees. However, duing to ITS polymorphism among individuals, it was necessary to detect putative pseu- dogenes. Additionally, utilization of multi-specific rDNA sequences to analyze phylogenetic implications probably has one bright future.
出处
《果树学报》
CAS
CSCD
北大核心
2012年第2期253-261,共9页
Journal of Fruit Science
基金
国家自然科学基金项目(30971990)
关键词
果树
RDNA
荧光原位杂交
比较定位
系统进化
Fruit tree
Ribosomal DNA （rDNA）
Fluorescence in situ hybridization （FISH）
Physical mapping
Phylogenetic evolution
