期刊
NATURE
卷 468, 期 7326, 页码 959-U358出版社
NATURE PUBLISHING GROUP
DOI: 10.1038/nature09560
关键词
-
资金
- National Institutes of Health [RO1 GM037049]
Changes in gene regulatory networks are a major source of evolutionary novelty(1-3). Here we describe a specific type of network rewiring event, one that intercalates a new level of transcriptional control into an ancient circuit. We deduce that, over evolutionary time, the direct ancestral connections between a regulator and its target genes were broken and replaced by indirect connections, preserving the overall logic of the ancestral circuit but producing a new behaviour. The example was uncovered through a series of experiments in three ascomycete yeasts: the bakers' yeast Saccharomyces cerevisiae, the dairy yeast Kluyveromyces lactis and the human pathogen Candida albicans. All three species have three cell types: two mating-competent cell forms (a and alpha) and the product of their mating (a/alpha), which is mating-incompetent. In the ancestral mating circuit, two homeodomain proteins, Mata1 and Mat alpha 2, form a heterodimer that directly represses four genes that are expressed only in a and alpha cells and are required for mating(4-6). In a relatively recent ancestor of K. lactis, a reorganization occurred. The Mata1-Mat alpha 2 heterodimer represses the same four genes (known as the core haploid-specific genes) but now does so indirectly through an intermediate regulatory protein, Rme1. The overall logic of the ancestral circuit is preserved (haploid-specific genes ON in a and alpha cells and OFF in a/alpha cells), but a new phenotype was produced by the rewiring: unlike S. cerevisiae and C. albicans, K. lactis integrates nutritional signals, by means of Rme1, into the decision of whether or not to mate.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据