Stably maintaining specific states of gene expression during cell division is crucial for cellular differentiation. In fission yeast, such patterns result from directed gene rearrangements and chromosomally inherited epigenetic gene control mechanisms that control mating cell type. Recent advances have shown that a specific DNA strand at the mat1 locus is "differentiated" by a novel strand-specific imprint so that nonequivalent sister chromatids are produced. Therefore, cellular differentiation is a natural consequence of the fact that DNA strands are complementary and nonequivalent. Another epigenetic control that "silences" library copies of mat-information is due to heterochromatin organization. This is a clear case where Mendel's gene is composed of DNA plus the associated epigenetic moiety. Following up on initial genetic studies with more recent molecular investigations, this system has become one of the prominent models to understand mechanisms of gene regulation, genome integrity, and cellular differentiation. By applying lessons learned from these studies, such epigenetic gene control mechanisms, which must be installed in somatic cells, might explain mechanisms of cellular differentiation and development in higher eukaryotes.

中文翻译：

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从裂变酵母交配型转换和沉默研究中吸取了教训。

在细胞分裂过程中稳定维持基因表达的特定状态对于细胞分化至关重要。在裂变酵母中，这种模式是由定向基因重排和控制交配细胞类型的染色体遗传表观遗传基因控制机制引起的。最近的进展表明，在mat1基因座处的特定DNA链通过新型链特异性印迹被“区分”，从而产生了不等价的姐妹染色单体。因此，细胞分化是DNA链互补且不相等这一事实的自然结果。“沉默”席子信息的文库副本的另一种表观遗传控制是由于异染色质的组织。这是一个明显的例子，孟德尔基因由DNA加上相关的表观遗传部分组成。在最初的遗传研究和最近的分子研究之后，该系统已成为了解基因调控，基因组完整性和细胞分化机制的重要模型之一。通过应用从这些研究中学到的经验教训，必须在体细胞中安装的这种表观遗传基因控制机制可以解释高等真核生物中细胞分化和发育的机制。