Klar A J, Strathern J N, Hicks J B
Cell. 1981 Aug;25(2):517-24. doi: 10.1016/0092-8674(81)90070-2.
Mating-type switches of the yeast Saccharomyces cerevisiae occur by unidirectional transposition of copies of unexpressed mating-type genetic information, residing at HML and HMR loci, into the expressed MAT locus. The HML and HMR loci remain unchanged. In contrast, in appropriate strains where the silent loci are also allowed to express, for example in mar mutants, efficient switches of HML and HMR are shown to occur at rates equivalent to those observed for MAT. Thus the position-effect control on the direction of transposition is affected by the state of expression of the locus under study the expressed loci switch regardless of their location.
酿酒酵母（Saccharomyces cerevisiae）的交配型转换是通过将位于HML和HMR位点的未表达交配型遗传信息的拷贝单向转座到表达的MAT位点来实现的。HML和HMR位点保持不变。相比之下，在适当的菌株中，沉默位点也被允许表达，例如在mar突变体中，HML和HMR的有效转换显示以与MAT观察到的速率相当的速率发生。因此，转座方向上的位置效应控制受所研究位点的表达状态影响，表达的位点无论其位置如何都会发生转换。
