Li Juan, Zhang Ke-Qin
Laboratory for Conservation and Utilization of Bio-resources, and Key Laboratory for Microbial Resources of the Ministry of Education, Yunnan University, Kunming, P.R. China.
PLoS One. 2014 Feb 28;9(2):e90225. doi: 10.1371/journal.pone.0090225. eCollection 2014.
To get a comprehensive view of fungal M35 family (deuterolysin) and M36 family (fungalysin) genes, we conducted genome-wide investigations and phylogenetic analyses of genes in these two families from 50 sequenced Ascomycota fungi with different life styles. Large variations in the number of M35 family and M36 family genes were found among different fungal genomes, indicating that these two gene families have been highly dynamic through fungal evolution. Moreover, we found obvious expansions of Meps in two families of Onygenales: Onygenaceae and Arthodermataceae, whereas species in family Ajellomycetace did not show expansion of these genes. The strikingly different gene duplication and loss patterns in Onygenales may be associated with the different pathogenicity of these species. Interestingly, likelihood ratio tests (LRT) of both M35 family and M36 family genes suggested that several branches leading to the duplicated genes in dermatophytic and Coccidioides fungi had signatures of positive selection, indicating that the duplicated Mep genes have likely diverged functionally to play important roles during the evolution of pathogenicity of dermatophytic and Coccidioides fungi. The potentially positively selected residues discovered by our analysis may have contributed to the development of new physiological functions of the duplicated Mep genes in dermatophytic fungi and Coccidioides species. Our study adds to the current knowledge of the evolution of Meps in fungi and also establishes a theoretical foundation for future experimental investigations.
为全面了解真菌M35家族（去甲溶素）和M36家族（真菌溶素）基因，我们对50种具有不同生活方式的已测序子囊菌门真菌中这两个家族的基因进行了全基因组研究和系统发育分析。在不同真菌基因组中发现M35家族和M36家族基因数量存在很大差异，这表明这两个基因家族在真菌进化过程中具有高度动态性。此外，我们发现发癣菌目两个科（发癣菌科和节皮菌科）中的Meps明显扩增，而阿耶洛菌科的物种未显示这些基因的扩增。发癣菌目中显著不同的基因复制和丢失模式可能与这些物种的不同致病性有关。有趣的是，M35家族和M36家族基因的似然比检验（LRT）表明，导致皮肤癣菌和球孢子菌中重复基因的几个分支具有正选择特征，这表明重复的Mep基因在功能上可能已经分化，在皮肤癣菌和球孢子菌致病性进化过程中发挥重要作用。我们分析发现的潜在正选择残基可能有助于皮肤癣菌和球孢子菌中重复Mep基因新生理功能的发展。我们的研究增加了目前对真菌中Meps进化的认识，也为未来的实验研究奠定了理论基础。
