Complexity and variability of gut commensal microbiota in polyphagous lepidopteran larvae.pdf

Complexity and Variability of Gut Commensal Microbiota in Polyphagous Lepidopteran Larvae Xiaoshu Tang1., Dalial Freitak2.¤, Heiko Vogel2*, Liyan Ping1*, Yongqi Shao1, Erika Arias Cordero1, Gary Andersen3, Martin Westermann4, David G. Heckel2, Wilhelm Boland1* 1 Department of Bioorganic Chemistry, Max Planck Institute for Chemical Ecology, Jena, Germany, 2 Department of Entomology, Max Planck Institute for Chemical Ecology, Jena, Germany, 3 Center for Environmental Biology and Molecular Microbial Ecology, Lawrence Berkeley National Laboratory, Berkeley, California, United States of America, 4 Centre of Electron Microscopy, The University Hospital, Friedrich Schiller University of Jena, Jena, Germany Abstract Background: The gut of most insects harbours nonpathogenic microorganisms. Recent work suggests that gut microbiota not only provide nutrients, but also involve in the development and maintenance of the host immune system. However, the complexity, dynamics and types of interactions between the insect hosts and their gut microbiota are far from being well understood. Methods/Principal Findings: To determine the composition of the gut microbiota of two lepidopteran pests, Spodoptera littoralis and Helicoverpa armigera, we applied cultivation-independent techniques based on 16S rRNA gene sequencing and microarray. The two insect species were very similar regarding high abundant bacterial families. Different bacteria colonize different niches within the gut. A core community, consisting of Enterococci, Lactobacilli, Clostridia, etc. was revealed in the insect larvae. These bacteria are constantly present in the digestion tract at relatively high frequency despite that developmental stage and diet had a great impact on shaping the bacterial communities. Some low-abundant species might become dominant upon loading external disturbances; the core community, however, did not change significantly. Clearly the insect gut selects for particular bacterial phylotypes. Conclu