This Article Full Text Full Text (PDF) Supplemental Research Data All Versions of this Article: gr.7144908v1 18/2/272    most recent Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Google Scholar Articles by Nikoh, N. Articles by Fukatsu, T. PubMed PubMed Citation Articles by Nikoh, N. Articles by Fukatsu, T. Pubmed/NCBI databases Nucleotide Protein Social Bookmarking                   What's this?

Letter

Wolbachia genome integrated in an insect chromosome: Evolution and fate of laterally transferred endosymbiont genes

¹ Division of Natural Sciences, The University of the Air, Chiba 261-8586, Japan; ² Institute for Biological Resources and Functions, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba 305-8566, Japan; ³ Biological Institute, Faculty of Education, Ehime University, Matsuyama 790-8577, Japan; ⁴ Environmental Biology Division, National Institute for Environmental Studies (NIES), Tsukuba 305-8506, Japan; ⁵ Department of Systems Sciences, University of Tokyo, Tokyo 153-8902, Japan

Recent accumulation of microbial genome data has demonstrated that lateral gene transfers constitute an important and universal evolutionary process in prokaryotes, while those in multicellular eukaryotes are still regarded as unusual, except for endosymbiotic gene transfers from mitochondria and plastids. Here we thoroughly investigated the bacterial genes derived from a Wolbachia endosymbiont on the nuclear genome of the beetle Callosobruchus chinensis. Exhaustive PCR detection and Southern blot analysis suggested that 30% of Wolbachia genes, in terms of the gene repertoire of wMel, are present on the insect nuclear genome. Fluorescent in situ hybridization located the transferred genes on the proximal region of the basal short arm of the X chromosome. Molecular evolutionary and other lines of evidence indicated that the transferred genes are probably derived from a single lateral transfer event. The transferred genes were, for the length examined, structurally disrupted, freed from functional constraints, and transcriptionally inactive. Hence, most, if not all, of the transferred genes have been pseudogenized. Notwithstanding this, the transferred genes were ubiquitously detected from Japanese and Taiwanese populations of C. chinensis, while the number of the transferred genes detected differed between the populations. The transferred genes were not detected from congenic beetle species, indicating that the transfer event occurred after speciation of C. chinensis, which was estimated to be one or several million years ago. These features of the laterally transferred endosymbiont genes are compared with the evolutionary patterns of mitochondrial and plastid genome fragments acquired by nuclear genomes through recent endosymbiotic gene transfers.

E-mail t-fukatsu{at}aist.go.jp; fax 81-29-861-6080.

[Supplemental material is available online at www.genome.org. The sequence data from this study have been submitted to GenBank under accession nos. EF534574–EF534700 and EF560581–EF560584.]

Article published online before print. Article and publication date are at http://www.genome.org/cgi/doi/10.1101/gr.7144908

CiteULike    Connotea    Del.icio.us    Digg    Reddit    Technorati    What's this?