摘要
用生物素标记的玉米１８ＳｒＲＮＡ、小麦５ＳｒＲＮＡ 及ｔＲＮＡ 的ｃＤＮＡ 作为探针，在Ｋ４Ｍ 树脂包埋的玉米（Ｚｅａ ｍ ａｙｓ）根尖超薄切片上进行原位杂交。杂交后，用与１０ ｎｍ 金颗粒相连的亲和素对杂交子在电镜下进行检测。结果发现，在玉米中期染色体中存在有１８ＳｒＲＮＡ、５ＳｒＲＮＡ 和ｔＲＮＡ 分子，这些ＲＮＡ分子在染色体中的分布是随机的，即这些ＲＮＡ 分子在染色体的内部和周边均有分布。５ＳｒＲＮＡ 和ｔＲ－ＮＡ 在染色体中和细胞质中的含量基本相等，而１８ＳｒＲＮＡ 在染色体中的含量则明显高于细胞质。这一结果表明染色体中的ＲＮＡ 一部分来自于核仁。
In situ hybridization using biotinylated cDNA probes of 18S rRNA,5S rRNA,tRNA fMet ,tRNA Cys ,tRNA Asn was performed on ultra thin sections of K4M embedded maize root tip.After hybridization,the biotinylated hybrids were detected with avidin coupled to 10 nm gold particles and then examined under the electron microscopy.The results showed that 18S rRNA,5S rRNA and tRNA all existed in the metaphase chromosomes at random.They were distributed not only in the interior of the chromosomes,but also in the periphery of the chromosomes.Three tRNAs and 5S rRNA in the chromosomes were equal in amount to that in the cytoplasm,but the amount of 18S rRNA in the chromosomes was much higher than that in the cytoplasm.These results indicated that a part of the RNAs in the chromosomes came from the nucleolus,while others came from the nucleoplasm.
基金
国家教委博士点基金
关键词
玉米
染色体
RNA
电镜原位杂交
Electron microscopy in situ hybridization
Metaphase chromosome
5S rRNA
tRNA
18S rRNA
