用常规电镜和整体银染电镜观察技术对小麦根端分生组织细胞核进行了研究，发现核仁与其周边染色质之间存在通道结构。初步分析认为，染色体NORS中的rDNA是通过该通道进入到核仁的纤维中心的。

The Drosophila kismet (kis) gene is a member of the trithorax group of homeotic gene activators. kis plays a dual role during Drosophila development as a transcriptional activator and as a transcriptional repressor. The kis gene encodes multiple, large nuclear proteins that are related to chromatin remodeling factors, including Brahma (BRM) (another member of the trithorax group) and dMi-2. To study interactions between KIS and its target genes, we looked at its distribution on salivary gland polytene chromosomes. KIS is associated with a number of sites on polytene chromosomes suggesting that it regulates a large number of Abstracts/R

By using the conventional microscopic technique, the ultrastructure of the nucleolar fibrillar centers of common wheat, onion, broad bean and soybean were studied. It was showed that the two types of fibrillar centers (FCs) "homogeneous" and "heterogeneous" presented in all of the root-tip meristematic cell nucleoli of the four plants. And it was more clearly in the root-tip meristematic cell nucleoli of common wheat stained by "en bloc" silver staining technique. The results demonstrated: (1) The two types of fibrillar centers are common in higher plants; (2) The silver nitrate could stain not only the active chromatins but the inactive ones.

Abstract. Common wheat root-tip meristematic cells were treated by low concentration of actinomycin D (ActD) and then "en bloc" stained by silver nitrate. It was showed under the TEM that typical nucleolar structure could not be formed but a granular and fibrillar composed network exhibited in the nucleolar region. Our result supports the opinion that there was really a relationship between nucleologenesis and the activation of RNA Polymerase (Poll) transcription. Furthermore, we infer that the network exhibited in the nucleolar region should be the nucleolar skeleton to support the nucleolus.