用原位杂交技术检测小麦异源染色质及定位核糖体DNA

IDENTIFICATION OF ALLEN CHROMATIN AND RIBOSOMAL DNA IN WHEAT BY IN SITU HYBRIDIZATION

本研究以六倍体小黑麦品系“Badger”(Triticale)1B/1R 易位系“宁8026”和1R(1D)代换系“84056-1-36-1”为材料制备染色体样本,以生物素标记的整个黑麦基因组 DNA 和小麦核糖体 DNA(rDNA)作探针进行原位杂交,结果如下:(1)利用整个黑麦基因组 DNA 作探针时,棕色的杂交信号分布于整个黑麦染色体上,使其与 Wrights 染色的小麦染色体明显不同,从而把“Badger”中的黑麦染色体与小麦染色体区分开来,并且确定了“宁 8026”中的1B/1R 易位染色体及易位断裂点。(2)在“Badger”和“84056-1-36-1”中分别检测出6个和8个含核糖体 DNA 的杂交位点,分布在1B、6B、1R 和5D上。(3)用原位杂交发现小麦核糖体 DNA 基因在细胞分裂间期的表达行为。

In situ hybridization was carried out to somatic cells of hexaploid Tritieale“Badger” 1B/1R translocation line“Ning 8026”and IR(ID)substitution line“84056—1—36—1”using biotin-labelled total rye genomic DNA and wheat rDNA as probes,the results were as follows: 1.The probe containing the total genomic DNA from rye hybridized to the entire length of all rye chromosomes,as a result of the formation of a brown precipitate over the sites of hybri- dization,the rye chromosomes could be distinguished from wheat chromosomes counterstai- ned by Wright's solution,the distinguishable appearance of the wheat and rye chromosomes resulted in an efficient method of detecting rye chromosome or segments in wheat. 2.When the probe PTA 71 containing wheat ribosomal DNA was used to hybridize to somatic chromoso- mes of“Badger”and“84056—1—36—1”,six signals in“Badger”and eight in“84056—1— 36—1”were observed on 1B,6B,1R and 5D,among which 1B and 6B showed large in situ signals corresponding to many copies of the genes. 3.The expression behavior of wheat rDNA was found in interphase cells by in situ hybridization.