Vasse Marie, Voglmayr Hermann, Mayer Veronika, Gueidan Cécile, Nepel Maximilian, Moreno Leandro, de Hoog Sybren, Selosse Marc-André, McKey Doyle, Blatrix Rumsaïs
CEFE UMR 5175, CNRS-Université de Montpellier-Université Paul Valéry Montpellier-EPHE, 1919 Route de Mende, 34293 Montpellier Cedex 5, France.
Division of Systematic and Evolutionary Botany, Department of Botany and Biodiversity Research, University of Vienna, Rennweg 14, 1030 Wien, Austria.
Proc Biol Sci. 2017 Mar 15;284(1850). doi: 10.1098/rspb.2016.2519.
The frequency and the geographical extent of symbiotic associations between ants and fungi of the order Chaetothyriales have been highlighted only recently. Using a phylogenetic approach based on seven molecular markers, we showed that ant-associated Chaetothyriales are scattered through the phylogeny of this order. There was no clustering according to geographical origin or to the taxonomy of the ant host. However, strains tended to be clustered according to the type of association with ants: strains from ant-made carton and strains from plant cavities occupied by ants ('domatia') rarely clustered together. Defining molecular operational taxonomic units (MOTUs) with an internal transcribed spacer sequence similarity cut-off of 99% revealed that a single MOTU could be composed of strains collected from various ant species and from several continents. Some ant-associated MOTUs also contained strains isolated from habitats other than ant-associated structures. Altogether, our results suggest that the degree of specialization of the interactions between ants and their fungal partners is highly variable. A better knowledge of the ecology of these interactions and a more comprehensive sampling of the fungal order are needed to elucidate the evolutionary history of mutualistic symbioses between ants and Chaetothyriales.
蚁类与散囊菌目真菌之间共生关系的频率和地理范围直到最近才受到关注。我们基于七个分子标记采用系统发育方法，结果表明与蚁类相关的散囊菌目真菌在该目系统发育中呈分散分布。未依据地理来源或蚁类宿主的分类学进行聚类。然而，菌株倾向于根据与蚁类的关联类型聚类：来自蚁制硬纸盒的菌株和来自蚁类占据的植物腔室（“虫瘿”）的菌株很少聚在一起。用内部转录间隔区序列相似度截断值为99%来定义分子操作分类单元（MOTUs），结果显示单个MOTU可能由从不同蚁种和各大洲采集的菌株组成。一些与蚁类相关的MOTUs还包含从非蚁类相关结构的栖息地分离出的菌株。总体而言，我们的结果表明蚁类与其真菌伙伴之间相互作用的专业化程度高度可变。需要更深入了解这些相互作用的生态学，并对该真菌目进行更全面的采样，以阐明蚁类与散囊菌目之间互利共生的进化历史。
