title: Horizontal Gene Transfer of Pectinases from Bacteria Preceded the Diversification of Stick and Leaf Insects.
abstract: Genes acquired by horizontal transfer are increasingly being found in animal genomes. Understanding their origin and evolution requires knowledge about the phylogenetic relationships from both source and recipient organisms. We used RNASeq data and respective assembled transcript libraries to trace the evolutionary history of polygalacturonase (pectinase) genes in stick insects (Phasmatodea). By mapping the distribution of pectinase genes on a Polyneoptera phylogeny, we identified the transfer of pectinase genes from known phasmatodean gut microbes into the genome of an early euphasmatodean ancestor that took place between 60 and 100 million years ago. This transfer preceded the rapid diversification of the suborder, enabling symbiont-free pectinase production that would increase the insects' digestive efficiency and reduce dependence on microbes. Bacteria-to-insect gene transfer was thought to be uncommon, however the increasing availability of large-scale genomic data may change this prevailing notion.
authors.affiliation: Department of Entomology, Max-Planck Institute für chemische Ökologie, Hans-Knöll-Str. 8, 07745 Jena Germany.
authors.forename: Matan
authors.initials: M
authors.lastname: Shelomi
authors.forename: Etienne G J
authors.initials: EG
authors.lastname: Danchin
authors.affiliation: Department of Entomology, Max-Planck Institute für chemische Ökologie, Hans-Knöll-Str. 8, 07745 Jena Germany.
authors.forename: David
authors.initials: D
authors.lastname: Heckel
authors.affiliation: Friedrich-Schiller-Universität Jena, Institut für Spezielle Zoologie und Evolutionsbiologie, Erbertstr. 1, 07743 Jena, Germany.
authors.forename: Benjamin
authors.initials: B
authors.lastname: Wipfler
authors.affiliation: Johann-Friedrich-Blumenbach-Institut für Zoologie und Anthropologie, Georg-August-Universität Göttingen, Berliner Str. 28, 37073 Göttingen, Germany.
authors.forename: Sven
authors.initials: S
authors.lastname: Bradler
authors.affiliation: China National GeneBank, BGI-Shenzhen, Beishan Road, Beishan Industrial Zone, Yantian District, 518083, Shenzhen, Guangdong Province, China.
authors.forename: Xin
authors.initials: X
authors.lastname: Zhou
authors.affiliation: Department of Entomology, Max-Planck Institute für chemische Ökologie, Hans-Knöll-Str. 8, 07745 Jena Germany.
authors.forename: Yannick
authors.initials: Y
authors.lastname: Pauchet
mesh_terms: D000818:Animals; D001419:Bacteria / Q000201:enzymology / Q000235:genetics*; D019143:Evolution, Molecular; D000069196:Gastrointestinal Microbiome; D022761:Gene Transfer, Horizontal; D019476:Insect Proteins / Q000235:genetics; D000074746:Neoptera / Q000201:enzymology* / Q000235:genetics; D010802:Phylogeny; D011096:Polygalacturonase / Q000235:genetics*; D017423:Sequence Analysis, RNA
chemical_list: D019476:Insect Proteins; D011096:Polygalacturonase