van Driel R, Humbel B, de Jong L
E.C. Slater Institute for Biochemical Research, University of Amsterdam, The Netherlands.
J Cell Biochem. 1991 Dec;47(4):311-6. doi: 10.1002/jcb.240470405.
Until recently our knowledge about the structural and functional organization of the cell nucleus was very limited. Recent technical developments in the field of ultrastructural analysis, combined with ongoing research on the properties of the nuclear matrix, give new insight into how the nucleus is structured. Two types of observations shape our ideas about nuclear organization. First, most nuclear functions (replication, transcription, RNA processing, and RNA transport) are highly localized within the nucleus, rather than diffusely distributed. Moreover, they are associated with the nuclear matrix. Second, chromatin is organized in discrete loops, bordered by nuclear matrix attachment sequences (MARs). Each loop may contain one or several genes. The arrangement of chromatin in loops has profound consequences for the regulation of gene expression.
直到最近，我们对细胞核的结构和功能组织的了解还非常有限。超微结构分析领域的最新技术发展，结合对核基质特性的持续研究，为细胞核的结构提供了新的见解。两类观察结果塑造了我们对细胞核组织的认识。首先，大多数核功能（复制、转录、RNA加工和RNA运输）在细胞核内高度定位，而非分散分布。此外，它们与核基质相关。其次，染色质以离散的环形式组织，由核基质附着序列（MARs）界定边界。每个环可能包含一个或几个基因。染色质成环排列对基因表达调控具有深远影响。
