Grewal S I, Klar A J
Gene Regulation and Chromosome Biology Laboratory, National Cancer Institute-Frederick Cancer Research and Development Center, Maryland 21702-1201, USA.
Cell. 1996 Jul 12;86(1):95-101. doi: 10.1016/s0092-8674(00)80080-x.
Inheritance of the active and inactive states of gene expression by individual cells is crucial for development. In fission yeast, mating-type region consists of three loci called mat1, mat2, and mat3. Transcriptionally silent mat2 and mat3 loci are separated by a 15 kb interval, designated the K-region, and serve as donors of information for transcriptionally active mat1 interconversion. In a strain carrying replacement of 7.5 kb of the K-region with the ura4 gene, we discovered that ura4 silencing and efficiency of mating-type switching were covariegated and were regulated by an epigenetic mechanism. Genetic analyses demonstrated that epigenetic states were remarkably stable not only in mitosis but also in meiosis and were linked to the mating-type region. This study indicates that different epigenetic states are heritable forms of chromatin organization at the mat region.
单个细胞对基因表达活性和非活性状态的遗传对于发育至关重要。在裂殖酵母中，交配型区域由称为mat1、mat2和mat3的三个基因座组成。转录沉默的mat2和mat3基因座被一个15 kb的间隔（称为K区域）隔开，并作为转录活性mat1相互转换的信息供体。在一个用ura4基因替换了7.5 kb K区域的菌株中，我们发现ura4沉默和交配型转换效率是共斑驳的，并且受表观遗传机制调控。遗传分析表明，表观遗传状态不仅在有丝分裂中而且在减数分裂中都非常稳定，并且与交配型区域相关联。这项研究表明，不同的表观遗传状态是mat区域染色质组织的可遗传形式。
