用原位杂交技术对玉米中期染色体中rRNA的研究

本文以玉米１７ＳｒＲＮＡ的ｃＤＮＡ作探针，采用缺口平移技术，用Ｂｉｏ－ｄＵＴＰ对该探针进行生物素标记。在Ｋ４Ｍ树脂包埋的玉米根尖超薄切片上进行原位杂交。杂交后，在电镜下通过与１０ｎｍ金颗粒相连的亲合素对杂交子进行检测，首次直接证实了除核仁，核质和细胞质外，ｒＲＮＡ在中期染色体上的存在。其分布特点是随机的，均匀的，并在数量上明显高于细胞质。

STUDIES ON rRNA IN METAPHASE CHROMOSOME OF ZEA MAYS BY IN SITU HYBRIDIZATION

In situ hybridization using cDNA probe of maize 175 rRNA, which was biotinylated by nick-translation technique with Bio-dUTP, was developed on the K4M-embedded ultrathin sections of Zea mays root tip. After hybridization, the biotinylated hybrids were detected with avidin coupled to 10 nm gold particles in electron micrscopy. Besides the presence in nucleolus, cytoplasm,nucleoplasm, rRNA was confirmed directly for the first time to exist in plant metaphase chromosome with higher amount than that in the cytoplasm. It was characterized by random and even distribution.