A divergent RWP-RK transcription factor determines mating type in heterothallic Closterium
A divergent RWP-RK transcription factor determines mating type in heterothallic Closterium
复制标题
不同的 RWP-RK 转录因子决定异宗新月菌的交配类型
作者：
Sekimoto;H.;Komiya;A.;Tsuyuki;N.;Kawai;J.;Kanda;N.;Ootsuki;R.;Suzuki;Y.;Toyoda;A.;Fujiyama;A.;Kasahara;M.;Abe;J.;Tsuchikane;Y.;Nishiyama;T.
peracerosum-strigosum-littoralcomplex（新月藻属，接合藻科）具有同花受精交配系统。Zygnematophyceae的成员是现存的陆地植物的最近的亲戚，并与绿藻模式，其中的交配型（MT）的决定的遗传基础已被报道。因此，我们调查了MT决定在新月藻。我们测序基因组代表两个MT，mt+和mt −，在新月藻和识别CpMinus 1，一个基因连锁的mt−表型。我们利用反向遗传学方法分析了它的功能。CpMinus 1编码一个趋异的RWP-RK结构域样转录因子，并在配子分化过程中特异性表达。将CpMinus 1导入到mt+菌株中足以将其转化为表型为mt−的菌株，而CpMinus 1-敲除mt −的菌株表型为mt+。我们认为CpMinus 1是通过唤起mt−表型和抑制mt+表型而在异宗配合的新月藻中起作用的主要MT决定因子。CpMinus 1可能在Zygnematophyceae谱系中独立进化，该谱系失去了卵-精异配交配系统。mt-特异性区域可能构成MT基因座，其侧翼是经历某种重组的共同序列。
TheClosterium peracerosum–strigosum–littoralecomplex (Closterium, Zygnematophyceae) has an isogamous mating system. Members of the Zygnematophyceae are the closest relatives to extant land plants and are distantly related to chlorophytic models, for which a genetic basis of mating type (MT) determination has been reported. We thus investigated MT determination in Closterium.We sequenced genomes representing the two MTs,mt+ andmt−, in Closterium and identifiedCpMinus1, a gene linked to the mt− phenotype. We analyzed its function using reverse genetics methods.CpMinus1encodes a divergent RWP‐RK domain‐containing‐like transcription factor and is specifically expressed during gamete differentiation. Introduction ofCpMinus1into anmt+ strain was sufficient to convert it to a phenotypically mt− strain, whileCpMinus1‐knockoutmt− strains were phenotypically mt+.We propose that CpMinus1 is the major MT determinant that acts by evoking the mt− phenotype and suppressing the mt+ phenotype in heterothallic Closterium.CpMinus1likely evolved independently in the Zygnematophyceae lineage, which lost an egg–sperm anisogamous mating system. mt− specific regions possibly constitute an MT locus flanked by common sequences that undergo some recombination.