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Nutritional upgrading for omnivorous carpenter ants by the endosymbiont Blochmannia.

Feldhaar, Heike; Straka, Josef LU ; Krischke, Markus; Berthold, Kristina; Stoll, Sascha; Mueller, Martin and Gross, Roy (2007) In BMC Biology 5(48).
Abstract
Background: Carpenter ants (genus Camponotus) are considered to be omnivores. Nonetheless, the genome sequence of Blochmannia floridanus, the obligate intracellular endosymbiont of Camponotus floridanus, suggests a function in nutritional upgrading of host resources by the bacterium. Thus, the
strongly reduced genome of the endosymbiont retains genes for all subunits of a functional urease, as well as those for biosynthetic pathways for all but one (arginine) of the amino acids essential to the host.
Results: Nutritional upgrading by Blochmannia was tested in 90-day feeding experiments with broodraising in worker-groups on chemically defined diets with and without essential amino acids and treated or not with antibiotics. Control... (More)
Background: Carpenter ants (genus Camponotus) are considered to be omnivores. Nonetheless, the genome sequence of Blochmannia floridanus, the obligate intracellular endosymbiont of Camponotus floridanus, suggests a function in nutritional upgrading of host resources by the bacterium. Thus, the
strongly reduced genome of the endosymbiont retains genes for all subunits of a functional urease, as well as those for biosynthetic pathways for all but one (arginine) of the amino acids essential to the host.
Results: Nutritional upgrading by Blochmannia was tested in 90-day feeding experiments with broodraising in worker-groups on chemically defined diets with and without essential amino acids and treated or not with antibiotics. Control groups were fed with cockroaches, honey water and Bhatkar agar.
Worker-groups were provided with brood collected from the queenright mother-colonies (45 eggs and 45 first instar larvae each). Brood production did not differ significantly between groups of symbiotic workers on diets with and without essential amino acids. However, aposymbiotic worker groups raised
significantly less brood on a diet lacking essential amino acids. Reduced brood production by aposymbiotic workers was compensated when those groups were provided with essential amino acids in their diet. Decrease of endosymbionts due to treatment with antibiotic was monitored by qRT-PCR and FISH after
the 90-day experimental period. Urease function was confirmed by feeding experiments using 15N-labelled urea. GC-MS analysis of 15N-enrichment of free amino acids in workers revealed significant labelling of the
non-essential amino acids alanine, glycine, aspartic acid, and glutamic acid, as well as of the essential amino acids methionine and phenylalanine.
Conclusion: Our results show that endosymbiotic Blochmannia nutritionally upgrade the diet of C. floridanus hosts to provide essential amino acids, and that it may also play a role in nitrogen recycling via its functional urease. Blochmannia may confer a significant fitness advantage via nutritional upgrading by enhancing competitive ability of Camponotus with other ant species lacking such an endosymbiont. Domestication of the endosymbiont may have facilitated the evolutionary success of the genus Camponotus. (Less)
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author
publishing date
type
Contribution to journal
publication status
published
subject
in
BMC Biology
volume
5
issue
48
publisher
BioMed Central
external identifiers
  • scopus:38349144037
ISSN
1741-7007
DOI
10.1186/1741-7007-5-48
language
English
LU publication?
no
id
a371056a-4ca8-410b-a8d3-ba05ba476639
date added to LUP
2016-10-24 16:23:23
date last changed
2017-11-12 04:25:23
@article{a371056a-4ca8-410b-a8d3-ba05ba476639,
  abstract     = {Background: Carpenter ants (genus Camponotus) are considered to be omnivores. Nonetheless, the genome sequence of Blochmannia floridanus, the obligate intracellular endosymbiont of Camponotus floridanus, suggests a function in nutritional upgrading of host resources by the bacterium. Thus, the<br/>strongly reduced genome of the endosymbiont retains genes for all subunits of a functional urease, as well as those for biosynthetic pathways for all but one (arginine) of the amino acids essential to the host.<br/>Results: Nutritional upgrading by Blochmannia was tested in 90-day feeding experiments with broodraising in worker-groups on chemically defined diets with and without essential amino acids and treated or not with antibiotics. Control groups were fed with cockroaches, honey water and Bhatkar agar.<br/>Worker-groups were provided with brood collected from the queenright mother-colonies (45 eggs and 45 first instar larvae each). Brood production did not differ significantly between groups of symbiotic workers on diets with and without essential amino acids. However, aposymbiotic worker groups raised<br/>significantly less brood on a diet lacking essential amino acids. Reduced brood production by aposymbiotic workers was compensated when those groups were provided with essential amino acids in their diet. Decrease of endosymbionts due to treatment with antibiotic was monitored by qRT-PCR and FISH after<br/>the 90-day experimental period. Urease function was confirmed by feeding experiments using 15N-labelled urea. GC-MS analysis of 15N-enrichment of free amino acids in workers revealed significant labelling of the<br/>non-essential amino acids alanine, glycine, aspartic acid, and glutamic acid, as well as of the essential amino acids methionine and phenylalanine.<br/>Conclusion: Our results show that endosymbiotic Blochmannia nutritionally upgrade the diet of C. floridanus hosts to provide essential amino acids, and that it may also play a role in nitrogen recycling via its functional urease. Blochmannia may confer a significant fitness advantage via nutritional upgrading by enhancing competitive ability of Camponotus with other ant species lacking such an endosymbiont. Domestication of the endosymbiont may have facilitated the evolutionary success of the genus Camponotus.},
  author       = {Feldhaar, Heike and Straka, Josef and Krischke, Markus and Berthold, Kristina and Stoll, Sascha and Mueller, Martin and Gross, Roy},
  issn         = {1741-7007},
  language     = {eng},
  month        = {10},
  number       = {48},
  publisher    = {BioMed Central},
  series       = {BMC Biology},
  title        = {Nutritional upgrading for omnivorous carpenter ants by the endosymbiont Blochmannia.},
  url          = {http://dx.doi.org/10.1186/1741-7007-5-48},
  volume       = {5},
  year         = {2007},
}