Kerényi Zoltán, Oláh Brigitta, Jeney Apor, Hornok László, Leslie John F
Agricultural Biotechnology Center, Szent-Györgyi A u 4, H-2100 Gödöll, Hungary.
Appl Environ Microbiol. 2006 Oct;72(10):6527-32. doi: 10.1128/AEM.01543-06.
For two fungal strains to be vegetatively compatible and capable of forming a stable vegetative heterokaryon they must carry matching alleles at a series of loci variously termed het or vic genes. Cloned het/vic genes from Neurospora crassa and Podospora anserina have no obvious functional similarity and have various cellular functions. Our objective was to identify the homologue of the Neurospora het-c gene in Fusarium proliferatum and to determine if this gene has a vegetative compatibility function in this economically important and widely dispersed fungal pathogen. In F. proliferatum and five other closely related Fusarium species we found a few differences in the DNA sequence, but the changes were silent and did not alter the amino acid sequence of the resulting protein. Deleting the gene altered sexual fertility as the female parent, but it did not alter male fertility or existing vegetative compatibility interactions. Replacement of the allele-specific portion of the coding sequence with the sequence of an alternate allele in N. crassa did not result in a vegetative incompatibility response in transformed strains of F. proliferatum. Thus, the fphch gene in Fusarium appears unlikely to have the vegetative compatibility function associated with its homologue in N. crassa. These results suggest that the vegetative compatibility phenotype may result from convergent evolution. Thus, the genes involved in this process may need to be identified at the species level or at the level of a group of species and could prove to be attractive targets for the development of antifungal agents.
为使两个真菌菌株在营养上兼容并能够形成稳定的营养异核体，它们必须在一系列不同称为het或vic基因的位点上携带匹配的等位基因。从粗糙脉孢菌和栗疫霉中克隆的het/vic基因没有明显的功能相似性，且具有多种细胞功能。我们的目标是鉴定层出镰刀菌中粗糙脉孢菌het - c基因的同源物，并确定该基因在这种经济上重要且广泛分布的真菌病原体中是否具有营养兼容性功能。在层出镰刀菌和其他五个密切相关的镰刀菌物种中，我们发现DNA序列存在一些差异，但这些变化是沉默的，并未改变所得蛋白质的氨基酸序列。删除该基因会改变作为母本的有性繁殖力，但不会改变父本繁殖力或现有的营养兼容性相互作用。用粗糙脉孢菌中另一个等位基因的序列替换编码序列的等位基因特异性部分，在转化的层出镰刀菌菌株中并未引发营养不亲和反应。因此，镰刀菌中的fphch基因似乎不太可能具有与其在粗糙脉孢菌中的同源物相关的营养兼容性功能。这些结果表明，营养兼容性表型可能是趋同进化的结果。因此，参与这一过程的基因可能需要在物种水平或一组物种的水平上进行鉴定，并且可能被证明是开发抗真菌剂的有吸引力的靶点。
