Phylogenic analysis of adhesion related genes Mad1 revealed a positive selection for the evolution of trapping devices of nematode-trapping fungi.
Phylogenic analysis of adhesion related genes Mad1 revealed a positive selection for the evolution of trapping devices of nematode-trapping fungi.
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粘附相关基因Mad1的系统发育分析揭示了线虫捕获真菌捕获装置进化的正选择
DOI：
10.1038/srep22609
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发表时间：
2016-03-04
影响因子：
4.6
通讯作者：
Zhang KQ
中科院分区：
文献类型：
--
作者：
Li J;Liu Y;Zhu H;Zhang KQ
黏附是细胞外纤维聚合物的主要成分，它聚集在线虫诱捕真菌的黏附陷阱的外表面，被认为在诱捕装置的进化过程中发挥了重要作用。基于黏附材料相关基因的系统发育分析对于了解捕集装置的进化具有重要意义。最近，昆虫病原真菌绿僵菌（Metarhizium anisopliae）细胞壁蛋白MAD1的同源基因AoMad1被功能表征为参与捕获线虫的真菌Arthrobotrys oligospora的粘附产生。在本研究中，我们用不同的诱捕装置从线虫诱捕真菌中克隆了Mad1同源基因。系统发育分析表明，形成非黏着收缩环陷阱的物种和形成黏着收缩环陷阱的物种沿两条谱系进化。似然比检验（LRT）表明，Mad1基因在线虫诱捕真菌的进化过程中可能发挥了重要的正向选择压力作用，包括粘附诱捕器和机械诱捕器。我们的研究为线虫诱捕真菌诱捕装置的进化提供了新的见解，也有助于理解粘附在线虫诱捕真菌进化过程中的重要性。
Adhesions, the major components of the extracellular fibrillar polymers which accumulate on the outer surface of adhesive traps of nematode-trapping fungi, are thought to have played important roles during the evolution of trapping devices. Phylogenetic analyses based on the genes related to adhesive materials can be of great importance for understanding the evolution of trapping devices. Recently, AoMad1, one homologous gene of the entomopathogenic fungus Metarhizium anisopliae cell wall protein MAD1, has been functionally characterized as involved in the production of adhesions in the nematode-trapping fungus Arthrobotrys oligospora. In this study, we cloned Mad1 homologous genes from nematode-trapping fungi with various trapping devices. Phylogenetic analyses suggested that species which formed nonadhesive constricting ring (CR) traps more basally placed and species with adhesive traps evolved along two lineages. Likelihood ratio tests (LRT) revealed that significant positive selective pressure likely acted on the ancestral trapping devices including both adhesive and mechanical traps, indicating that the Mad1 genes likely played important roles during the evolution of nematode-trapping fungi. Our study provides new insights into the evolution of trapping devices of nematode-trapping fungi and also contributes to understanding the importance of adhesions during the evolution of nematode-trapping fungi.