Two Host Clades, Two Bacterial Arsenals: Evolution through Gene Losses in Facultative Endosymbionts
Por:
Rollat-Farnier PA, Santos-Garcia D, Rao Q, Sagot MF, Silva FJ, Henri H, Zchori-Fein E, Latorre A, Moya A, Barbe V, Liu SS, Wang XW, Vavre F and Mouton L
Publicada:
1 mar 2015
Resumen:
Bacterial endosymbiosis is an important evolutionary process in insects, which can harbor both obligate and facultative symbionts. The evolution of these symbionts is driven by evolutionary convergence, and they exhibit among the tiniest genomes in prokaryotes. The large host spectrum of facultative symbionts and the high diversity of strategies they use to infect new hosts probably impact the evolution of their genome and explain why they undergo less severe genomic erosion than obligate symbionts. Candidatus Hamiltonella defensa is suitable for the investigation of the genomic evolution of facultative symbionts because the bacteria are engaged in specific relationships in two clades of insects. In aphids, H. defensa is found in several species with an intermediate prevalence and confers protection against parasitoids. In whiteflies, H. defensa is almost fixed in some species of Bemisia tabaci, which suggests an important role of and a transition toward obligate symbiosis. In this study, comparisons of the genome of H. defensa present in two B. tabaci species ( Middle East Asia Minor 1 and Mediterranean) and in the aphid Acyrthosiphon pisum revealed that they belong to two distinct clades and underwent specific gene losses. In aphids, it contains highly virulent factors that could allow protection and horizontal transfers. In whiteflies, the genome lost these factors and seems to have a limited ability to acquire genes. However it contains genes that could be involved in the production of essential nutrients, which is consistent with a primordial role for this symbiont. In conclusion, although both lineages of H. defensa have mutualistic interactions with their hosts, their genomes follow distinct evolutionary trajectories that reflect their phenotype and could have important consequences on their evolvability.
Filiaciones:
Rollat-Farnier PA:
Laboratoire de Biométrie et Biologie Evolutive, UMR CNRS 5558, Université de Lyon, Université Lyon1, Villeurbanne, France BAMBOO Research Team, INRIA Grenoble, Rhône-Alpes, France
Santos-Garcia D:
Institut Cavanilles de Biodiversitat i Biologia Evolutiva, Universitat de València, Spain
Rao Q:
Ministry of Agriculture Key Laboratory of Agricultural Entomology, Institute of Insect Sciences, Zhejiang University, Hangzhou, China School of Agriculture and Food Science, Zhejiang Agriculture and Forestry University, Lin'an, Hangzhou, China
Sagot MF:
Laboratoire de Biométrie et Biologie Evolutive, UMR CNRS 5558, Université de Lyon, Université Lyon1, Villeurbanne, France BAMBOO Research Team, INRIA Grenoble, Rhône-Alpes, France
Silva FJ:
Institut Cavanilles de Biodiversitat i Biologia Evolutiva, Universitat de València, Spain Unidad Mixta de Investigación en Genómica y Salud de la Fundación para el Fomento de la Investigación Sanitaria y Biomédica de la Comunidad Valenciana (FISABIO-Salud Pública) y el Instituto Cavanilles de Biodiversitad y Biología Evolutiva (Universitat de València), Valencia, Spain
Henri H:
Laboratoire de Biométrie et Biologie Evolutive, UMR CNRS 5558, Université de Lyon, Université Lyon1, Villeurbanne, France
Zchori-Fein E:
Department of Entomology, NeweYa'ar Research Center, Agricultural Research Organization, Ramat Yishay, Israel
:
Institut Cavanilles de Biodiversitat i Biologia Evolutiva, Universitat de València, Spain Unidad Mixta de Investigación en Genómica y Salud de la Fundación para el Fomento de la Investigación Sanitaria y Biomédica de la Comunidad Valenciana (FISABIO-Salud Pública) y el Instituto Cavanilles de Biodiversitad y Biología Evolutiva (Universitat de València), Valencia, Spain
:
Institut Cavanilles de Biodiversitat i Biologia Evolutiva, Universitat de València, Spain Unidad Mixta de Investigación en Genómica y Salud de la Fundación para el Fomento de la Investigación Sanitaria y Biomédica de la Comunidad Valenciana (FISABIO-Salud Pública) y el Instituto Cavanilles de Biodiversitad y Biología Evolutiva (Universitat de València), Valencia, Spain
Barbe V:
CEA/DSV/IG/Genoscope, 2 rue Gaston Cremieux, Evry, France
Liu SS:
Ministry of Agriculture Key Laboratory of Agricultural Entomology, Institute of Insect Sciences, Zhejiang University, Hangzhou, China
Wang XW:
Ministry of Agriculture Key Laboratory of Agricultural Entomology, Institute of Insect Sciences, Zhejiang University, Hangzhou, China
Vavre F:
Laboratoire de Biométrie et Biologie Evolutive, UMR CNRS 5558, Université de Lyon, Université Lyon1, Villeurbanne, France BAMBOO Research Team, INRIA Grenoble, Rhône-Alpes, France
Green Published, Green Submitted, gold
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