Evolution of the MAT locus and its Ho endonuclease in yeast species
Evolution of the MAT locus and its Ho endonuclease in yeast species
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DOI：
10.1073/pnas.0304170101
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发表时间：
2004-02-10
影响因子：
11.1
通讯作者：
Wolfe, KH
中科院分区：
文献类型：
--
作者：
Butler, G;Kenny, C;Wolfe, KH
交配型（MAT）基因座的遗传学已经在酿酒酵母中得到了广泛的研究，但对这个复杂系统如何进化的了解相对较少。我们比较了组织MAT和交配型样（MTL）基因座在九个物种跨越半子囊菌系统发育树。我们推断，该系统在一个两步的过程中，其中沉默的HMR/HML盒出现，其次是收购的Ho核酸内切酶从移动的遗传元件。HO介导的活性MAT基因座和沉默盒之间的转换仅存在于严格意义上的酵母菌群及其近亲：光滑假丝酵母、德尔芬克鲁维酵母和卡氏酵母。我们将光滑念珠菌MTL 1鉴定为K. delphensis的研究，并显示光滑念珠菌MTL 1a和MTL 1 α基因型之间的转换发生在体内。更远的相关物种乳酸克鲁维酵母具有沉默盒，但在没有Ho内切核酸酶的帮助下转换交配型。非常远亲的物种，如白色念珠菌和解脂耶氏酵母没有沉默盒。在一个同宗配合的物种Pichia angusta中，我们发现MATalpha 2、MATalpha 1和MATa 1基因在同一条染色体上彼此相邻。虽然一些连续性的染色体定位的MAT基因座可以追溯到整个半子囊菌的进化，甚至链孢霉，该基因座的基因内容已经改变了一个HMG结构域基因（MATa 2）的损失后不久，从MATa的HO被招募的独特型。
The genetics of the mating-type (MAT) locus have been studied extensively in Saccharomyces cerevisiae, but relatively little is known about how this complex system evolved. We compared the organization of MAT and mating-type-like (MTL) loci in nine species spanning the hemiascomycete phylogenetic tree. We inferred that the system evolved in a two-step process in which silent HMR/HML cassettes appeared, followed by acquisition of the Ho endonuclease from a mobile genetic element. Ho-mediated switching between an active MAT locus and silent cassettes exists only in the Saccharomyces sensu stricto group and their closest relatives: Candida glabrata, Kluyveromyces delphensis, and Saccharomyces castellii. We identified C glabrata MTL1 as the ortholog of the MAT locus of K. delphensis and show that switching between C glabrata MTL1a and MTLlalpha genotypes occurs in vivo. The more distantly related species Kluyveromyces lactis has silent cassettes but switches mating type without the aid of Ho endonuclease. Very distantly related species such as Candida albicans and Yarrowia lipolytica do not have silent cassettes. In Pichia angusta, a homothallic species, we found MATalpha2, MATalpha1, and MATa1 genes adjacent to each other on the same chromosome. Although some continuity in the chromosomal location of the MAT locus can be traced throughout hemiascomycete evolution and even to Neurospora, the gene content of the locus has changed with the loss of an HMG domain gene (MATa2) from the MATa idiomorph shortly after HO was recruited.