School of Medicine, Conway Institute, University College Dublin, Dublin 4, Ireland; email:
School of Biomolecular and Biomedical Science, Conway Institute, University College Dublin, Dublin 4, Ireland; email:
Annu Rev Microbiol. 2017 Sep 8;71:197-214. doi: 10.1146/annurev-micro-090816-093403. Epub 2017 Jun 28.
The fungal phylum Ascomycota comprises three subphyla: Saccharomycotina, Pezizomycotina, and Taphrinomycotina. In many Saccharomycotina species, cell identity is determined by genes at the MAT (mating-type) locus; mating occurs between MATa and MATα cells. Some species can switch between MATa and MATα mating types. Switching in the Saccharomycotina originated in the common ancestor of the Saccharomycetaceae, Pichiaceae, and Metschnikowiaceae families, as a flip/flop mechanism that inverted a section of chromosome. Switching was subsequently lost in the Metschnikowiaceae, including Candida albicans, but became more complex in the Saccharomycetaceae when the mechanism changed from inversion to copy-and-paste between HML/HMR and MAT. Based on their phylogenetic closeness and the similarity of their MTL (mating-type like) loci, some Metschnikowia species may provide useful models for the sexual cycles of Candida species. Conservation of synteny demonstrates that, despite changes in its gene content, a single orthologous locus (MAT/MTL) has controlled cell type throughout ascomycete evolution.
酵母菌亚门、散囊菌亚门和粪壳菌亚门。在许多酵母菌物种中，细胞身份由 MAT（交配型）基因座上的基因决定；交配发生在 MATa 和 MATα 细胞之间。一些物种可以在 MATa 和 MATα 交配类型之间切换。子囊菌中的这种转换起源于酿酒酵母科、毕赤酵母科和汉逊酵母科的共同祖先，是一种翻转/翻转机制，它反转了染色体的一部分。这种转换随后在汉逊酵母科中丢失，包括白色念珠菌，但在酿酒酵母科中变得更加复杂，因为机制从倒位变为 HML/HMR 和 MAT 之间的复制粘贴。基于它们的系统发育关系和 MTL（交配型样）基因座的相似性，一些粘红酵母物种可能为白色念珠菌等物种的有性周期提供有用的模型。同线性的保守性表明，尽管其基因内容发生了变化，但单个直系同源基因座（MAT/MTL）在整个子囊菌进化过程中控制着细胞类型。
