结构异染色质（constitutive heterchromatin）除复制期外在细胞的所有时期都保持聚缩状态的染色质。主要由高度重复序列DNA构成。
如此大量的结构异染色质的来源及其在染色体组型进化和物种形成中的任务仍是一个谜。
The origin of such large amounts of constitutive heterochromatin and their role in karyotype evolution and speciation remain a mystery.
概述了异染色质生化组成及其在超微结构方面的研究进展，着重介绍了着丝粒的异染色质超微结构研究。
The paper has summarized development of biochemical component and ultrastructure of heterochromatin in eukaryote with an introduction to the development of ultrastructure in centromere.
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