Raudaskoski Marjatta, Kothe Erika
Friedrich Schiller University, Institute of Microbiology, Microbial Phytopathology, Neugasse 25, Jena, Germany.
Eukaryot Cell. 2010 Jun;9(6):847-59. doi: 10.1128/EC.00319-09. Epub 2010 Feb 26.
The genome sequences of the basidiomycete Agaricomycetes species Coprinopsis cinerea, Laccaria bicolor, Schizophyllum commune, Phanerochaete chrysosporium, and Postia placenta, as well as of Cryptococcus neoformans and Ustilago maydis, are now publicly available. Out of these fungi, C. cinerea, S. commune, and U. maydis, together with the budding yeast Saccharomyces cerevisiae, have been investigated for years genetically and molecularly for signaling in sexual reproduction. The comparison of the structure and organization of mating type genes in fungal genomes reveals an amazing conservation of genes regulating the sexual reproduction throughout the fungal kingdom. In agaricomycetes, two mating type loci, A, coding for homeodomain type transcription factors, and B, encoding a pheromone/receptor system, regulate the four typical mating interactions of tetrapolar species. Evidence for both A and B mating type genes can also be identified in basidiomycetes with bipolar systems, where only two mating interactions are seen. In some of these fungi, the B locus has lost its self/nonself discrimination ability and thus its specificity while retaining the other regulatory functions in development. In silico analyses now also permit the identification of putative components of the pheromone-dependent signaling pathways. Induction of these signaling cascades leads to development of dikaryotic mycelia, fruiting body formation, and meiotic spore production. In pheromone-dependent signaling, the role of heterotrimeric G proteins, components of a mitogen-activated protein kinase (MAPK) cascade, and cyclic AMP-dependent pathways can now be defined. Additionally, the pheromone-dependent signaling through monomeric, small GTPases potentially involved in creating the polarized cytoskeleton for reciprocal nuclear exchange and migration during mating is predicted.
担子菌纲伞菌目真菌灰盖鬼伞、双色蜡蘑、裂褶菌、黄孢原毛平革菌和展齿革菌，以及新生隐球菌和玉米黑粉菌的基因组序列现已公开。在这些真菌中，灰盖鬼伞、裂褶菌和玉米黑粉菌，连同出芽酵母酿酒酵母，多年来一直从遗传学和分子层面研究其有性生殖中的信号传导。真菌基因组中交配型基因的结构和组织比较显示，整个真菌界调控有性生殖的基因惊人地保守。在伞菌目中，两个交配型位点，A位点编码同源异型域型转录因子，B位点编码信息素/受体系统，调控四极性物种的四种典型交配相互作用。在具有双极性系统的担子菌中也能鉴定出A和B交配型基因的证据，在这种系统中只可见两种交配相互作用。在其中一些真菌中，B位点已失去自我/非自我识别能力，因而失去其特异性，但在发育过程中保留了其他调控功能。现在通过计算机分析也能够鉴定信息素依赖性信号通路的假定成分。这些信号级联的诱导导致双核菌丝体的发育、子实体形成和减数分裂孢子产生。在信息素依赖性信号传导中，现在可以确定异源三聚体G蛋白、丝裂原活化蛋白激酶（MAPK）级联的成分和环磷酸腺苷依赖性途径的作用。此外，预计通过单体小GTP酶的信息素依赖性信号传导可能参与在交配过程中为相互的核交换和迁移创建极化细胞骨架。
