Journal Article

Genome Economization in the Endosymbiont of the Wood Roach <i>Cryptocercus punctulatus</i> Due to Drastic Loss of Amino Acid Synthesis Capabilities

Alexander Neef, Amparo Latorre, Juli Peretó, Francisco J. Silva, Miguel Pignatelli and Andrés Moya

in Genome Biology and Evolution

Published on behalf of Society for Molecular Biology and Evolution

Volume 3, issue , pages 1437-1448
Published in print January 2011 |
Published online November 2011 | e-ISSN: 1759-6653 | DOI: http://dx.doi.org/10.1093/gbe/evr118

More Like This

Show all results sharing these subjects:

  • Bioinformatics and Computational Biology
  • Evolutionary Biology
  • Genetics and Genomics

GO

Show Summary Details

Preview

Cockroaches (Blattaria: Dictyoptera) harbor the endosymbiont Blattabacterium sp. in their abdominal fat body. This endosymbiont is involved in nitrogen recycling and amino acid provision to its host. In this study, the genome of Blattabacterium sp. of Cryptocercus punctulatus (BCpu) was sequenced and compared with those of the symbionts of Blattella germanica and Periplaneta americana, BBge and BPam, respectively. The BCpu genome consists of a chromosome of 605.7 kb and a plasmid of 3.8 kb and is therefore approximately 31 kb smaller than the other two aforementioned genomes. The size reduction is due to the loss of 55 genes, 23 of which belong to biosynthetic pathways for amino acids. The pathways for the production of tryptophan, leucine, isoleucine/threonine/valine, methionine, and cysteine have been completely lost. Additionally, the genes for the enzymes catalyzing the last steps of arginine and lysine biosynthesis, argH and lysA, were found to be missing and pseudogenized, respectively. These gene losses render BCpu auxotrophic for nine amino acids more than those corresponding to BBge and BPam. BCpu has also lost capacities for sulfate reduction, production of heme groups, as well as genes for several other unlinked metabolic processes, and genes present in BBge and BPam in duplicates. Amino acids and cofactors that are not synthesized by BCpu are either produced in abundance by hindgut microbiota or are provisioned via a copious diet of dampwood colonized by putrefying microbiota, supplying host and Blattabacterium symbiont with the necessary nutrients and thus permitting genome economization of BCpu.

Keywords: symbiosis; genome reduction; Blattabacterium; Bacteroidetes; metabolic pathway loss; wood-feeding

Journal Article.  6891 words.  Illustrated.

Subjects: Bioinformatics and Computational Biology ; Evolutionary Biology ; Genetics and Genomics

Users without a subscription are not able to see the full content. Please, subscribe or login to access all content.