INRAE, MycSA, Mycologie et Sécurité des Aliments, 33882 Villenave d'Ornon, France.
Ecologie Systématique Evolution, Bâtiment 360, CNRS, AgroParisTech, Université Paris-Saclay, 91400 Orsay, France.
Genes (Basel). 2021 Jul 16;12(7):1079. doi: 10.3390/genes12071079.
In heterothallic basidiomycete fungi, sexual compatibility is restricted by mating types, typically controlled by two loci: , encoding pheromone precursors and pheromone receptors, and , encoding two types of homeodomain transcription factors. We analysed the single mating-type locus of the commercial button mushroom variety, var. , and of the related variety . We identified the location of the mating-type locus using genetic map and genome information, corresponding to the locus, the locus having lost its mating-type role. We found the and genes flanking the genes as in several Agaricomycetes, two copies of the gene, an additional copy in the reference genome of var. and an additional copy in the reference genome of var. We detected a 140 kb-long inversion between mating types in an var. heterokaryon, trapping the genes, the gene and fragments of additional genes. The two varieties had islands of transposable elements at the mating-type locus, spanning 35 kb in the var. reference genome. Linkage analyses showed a region with low recombination in the mating-type locus region in the var. variety. We found high differentiation between alleles in both varieties, indicating an ancient event of recombination suppression, followed more recently by a suppression of recombination at the gene through the inversion in var. and a suppression of recombination across whole chromosomes in var. , constituting stepwise recombination suppression as in many other mating-type chromosomes and sex chromosomes.
在异宗配合的担子菌真菌中，有性繁殖的相容性受交配型限制，通常由两个基因座控制：编码信息素前体和信息素受体的 和编码两种类型的同源域转录因子的 。我们分析了商业纽扣菇品种 var. 的单交配型基因座，以及相关品种 var. 。我们使用遗传图谱和基因组信息确定了交配型基因座的位置，对应于 基因座，而 基因座已经失去了其交配型作用。我们发现 和 基因位于 基因的侧翼，与几种伞菌目真菌相同，有两个 基因拷贝，在 var. 参考基因组中有一个额外的 拷贝，在 var. 参考基因组中有一个额外的 拷贝。我们在一个 var. 异核体中检测到 140kb 长的交配型之间的倒位，捕获了 基因、 基因和其他基因的片段。这两个品种在交配型基因座有一个长 35kb 的转座元件岛，在 var. 参考基因组中有一个长 35kb 的转座元件岛。连锁分析显示在 var. 品种的交配型基因座区域有一个低重组区域。我们发现这两个品种的 等位基因之间有很高的分化，表明存在一个古老的重组抑制事件，随后在 var. 中通过倒位抑制了 基因的重组，在 var. 中抑制了整个染色体的重组，这与许多其他交配型染色体和性染色体一样，构成了逐步的重组抑制。
