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Unprecedented loss of ammonia assimilation capability in a urease-encoding bacterial mutualist
- Source :
- BMC Genomics, BMC Genomics, Vol 11, Iss 1, p 687 (2010)
- Publication Year :
- 2010
-
Abstract
- Background Blochmannia are obligately intracellular bacterial mutualists of ants of the tribe Camponotini. Blochmannia perform key nutritional functions for the host, including synthesis of several essential amino acids. We used Illumina technology to sequence the genome of Blochmannia associated with Camponotus vafer. Results Although Blochmannia vafer retains many nutritional functions, it is missing glutamine synthetase (glnA), a component of the nitrogen recycling pathway encoded by the previously sequenced B. floridanus and B. pennsylvanicus. With the exception of Ureaplasma, B. vafer is the only sequenced bacterium to date that encodes urease but lacks the ability to assimilate ammonia into glutamine or glutamate. Loss of glnA occurred in a deletion hotspot near the putative replication origin. Overall, compared to the likely gene set of their common ancestor, 31 genes are missing or eroded in B. vafer, compared to 28 in B. floridanus and four in B. pennsylvanicus. Three genes (queA, visC and yggS) show convergent loss or erosion, suggesting relaxed selection for their functions. Eight B. vafer genes contain frameshifts in homopolymeric tracts that may be corrected by transcriptional slippage. Two of these encode DNA replication proteins: dnaX, which we infer is also frameshifted in B. floridanus, and dnaG. Conclusions Comparing the B. vafer genome with B. pennsylvanicus and B. floridanus refines the core genes shared within the mutualist group, thereby clarifying functions required across ant host species. This third genome also allows us to track gene loss and erosion in a phylogenetic context to more fully understand processes of genome reduction.
- Subjects :
- food.ingredient
lcsh:QH426-470
lcsh:Biotechnology
Molecular Sequence Data
Blochmannia
Context (language use)
Replication Origin
Genome
DnaG
Evolution, Molecular
03 medical and health sciences
Ureaplasma
food
Enterobacteriaceae
Phylogenetics
Ammonia
Glutamate-Ammonia Ligase
lcsh:TP248.13-248.65
Genetics
Animals
Frameshift Mutation
Symbiosis
Gene
Phylogeny
030304 developmental biology
0303 health sciences
Base Composition
biology
Phylogenetic tree
Base Sequence
030306 microbiology
Ants
biology.organism_classification
Urease
lcsh:Genetics
Genes, Bacterial
Multigene Family
DNA, Intergenic
Poly A
Gene Deletion
Metabolic Networks and Pathways
Biotechnology
Research Article
Subjects
Details
- ISSN :
- 14712164
- Volume :
- 11
- Database :
- OpenAIRE
- Journal :
- BMC genomics
- Accession number :
- edsair.doi.dedup.....0a428a8eda99423cae1a504116a23034