豌豆细胞核仁中rDNA的超微定位和排布构型

IN SITU DISTRIBUTION AND CONFIGURATION OF rDNA IN THE NUCLEOLUS OF PISUM SATIVUM

利用细胞化学DNA特异染色法——NAMA-Ur特异染色法对豌豆细胞核仁中rDNA的位置及其排布构型进行了原位观察。结果表明,核仁中的rDNA位于纤维中心(FC)以及FC与致密纤维组分的交界处,以环绕FC的形式排布。不同位置的rDNA成分都具有集缩和解集缩两种形态结构,核仁外的核仁伴随染色质经过核仁通道进入核仁,沿FC周边排列,与其中的DNA相连。

Distribution and configuration of nucleolar DNA in the nucleolus of pea ( Pisum sativum) were analyzed using cytochemical NAMA-Ur DNA specific stain method. The results showed that nucleolar DNA distributed in FC and juncture of FC/DFC in the forms of surrounding FC. rDNA in different positions existed in either condensed or uncondensed forms. Nucleolus-associal-ed chromatin outside nucleolus extended in the periphery of FC via channels in the nucleolus.