有丝分裂前期蚕豆核仁解体的电镜观察

TEM OBSERVATIONS ON THE DISINTEGRATION OF BROADBEAN(VICIA FABA)NUCLEOLI DURING MITOTIC PROPHASE

本文运用电镜超薄切片、常规染色、Bernhard 染色等方法对蚕豆根端分生组织细胞核仁在有丝分裂前期的解体过程进行了观察,发现:在前期较早时候,与核仁有关的染色质提前集缩;随着前期的进展、核仁 RNP 物质不断向周围分散,核仁体积逐渐缩小;在前期末时核仁的轮廓消失,但一种称为宿存核仁的特殊结构仍然存在。本文对与核仁有关的染色质的提前集缩和宿存核仁等问题进行了讨论。

Ultrastructural and cytochemical studies on the disintegration of broadbean nucleoli during mitotic prophase were carried out with conventional staining tcchnique and RNP preferential staining technique (BernhardPs technique).We observed that the changes In shape and the gradual reduction in size of the nucleolus were accompanied by the dispersion of nucleolar RNP material in the surrounding nuclear sap. Furthermore,two special events were noticed:the early condensation of the chromatin which was related to the nucleolus,and the persis- tence of a condensed structre that appeared among the disintegrated nucleolus at the end of prophase.The significance of these events, in relation to the condensation of nucleolar chromatin and the nature of persistent nucleoli,is discussed in this paper.