利用蛋白表达谱鉴定毛壳属真菌2个种的子囊果毛形态变异性

Protein expression patterns identify morphological variability of ascomatal hairs in two species of genus Chaetomium

【目的】毛壳属真菌的子囊果毛形态曾是重要的分类性状,但因容易发生变异,在现代毛壳属的分类中它们的分类学价值受到质疑。印度毛壳(Chaetomium indicum)和绳生毛壳(Chaetomium funicola)是2个依据子囊果毛形态差异定义的物种,本研究旨在从蛋白表达谱水平认识这2个种的差异及其子囊果毛的变异性,同时探讨蛋白表达谱在真菌分类中的应用价值。【方法】通过形态学观察获得印度毛壳和绳生毛壳典型菌株和子囊果毛形态变异菌株,利用双向电泳技术对典型菌株和变异菌株的蛋白表达谱进行分析和比较。【结果】双向电泳(2DE)图谱特征反映出印度毛壳和绳生毛壳之间的蛋白表达谱差异明显。根据Neighbor-joining(NJ)算法生成的系统发育树进一步显示印度毛壳和绳生毛壳分别聚在2个不同分支,即同一种的典型菌株和变异菌株聚在一起。【结论】依据子囊果毛形态特征和种特异性的蛋白表达谱特征对印度毛壳和绳生毛壳的分类结果是一致的,表明子囊果毛特征仍然是毛壳属真菌分类的重要指标。

[Objective] Morphology of ascomatal hairs was traditionally used as a primary character in the classification of the fungal genus Chaetomium.However,the taxonomic value of ascomatal hair morphology is questioned in modern taxonomy of Chaetomium.Chaetomium indicum and C.funicola are two species proposed only by their differences in ascomatal hairs.The aim of this study is to understand the difference between these two species and their variability in the morphology of ascomatal hairs at the level of protein expression patterns,as well as to ressess the taxonomic value of the ascomatal hairs.[Methods] We performed microscopic examination to obtain the morphological characters of the typical and variable strains in both C.indicum and C.funicola.Then we used two-dimensional gel electrophoresis（2DE） to compare the protein expression patterns of the two species,including their typical and variable strains.[Results]The comparison of the obtained 2DE maps indicated that C.indicum and C.funicola exhibited species-specific protein expression patterns.The phylogenetic tree derived from the distance matrix of expression patterns with Neighbor-joining algorithm also revealed that the tested strains of C.indicum and C.funicola fell into two distinct clades,among which the variant strains were grouped together with the typical strains of the same species.[Conclusion] The consistency of species delimitation between C.indicum and C.funicola based on morphological characters of ascomatal hairs and species-specific protein expression patterns demonstrates that ascomatal hairs can be still used as potential morphological parameters in taxonomy of Chaetomium.