Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1451
pubmed:dateCreated
2000-12-11
pubmed:abstractText
Buchnera, the primary bacterial endosymbiont of aphids, is known to provision essential amino acids lacking in the hosts' diet of plant sap. The recent discovery of silenced copies of genes for tryptophan biosynthesis (trpEG) in certain Buchnera lineages suggests a decay in symbiotic functions in some aphid species. However, neither the distribution of pseudogenes among lineages nor the impact of this gene silencing on amino-acid availability in hosts has been assessed. In Buchnera of the aphid Diuraphis noxia, tandem repeats of these pseudogenes have persisted in diverse lineages, and thpEG pseudogenes have originated at least twice within this aphid genus. Measures of amino-acid concentrations in Diuraphis species have shown that the presence of the pseudogene is associated with a decreased availability of tryptophan, indicating that gene silencing decreases nutrient provisioning by symbionts. In Buchnera of Diuraphis, rates of nonsynonymous substitutions are elevated in functional trpE copies, supporting the hypothesis that pseudogene origin and persistence reflect a reduced selection for symbiont biosynthetic contributions. The parallel evolution of trpEG pseudogenes in Buchnera of Diuraphis and certain other aphid hosts suggests that either selection at the host level is not effective or that fitness in these aphids is not limited by tryptophan availability.
pubmed:commentsCorrections
http://linkedlifedata.com/resource/pubmed/commentcorrection/10983826-10383681, http://linkedlifedata.com/resource/pubmed/commentcorrection/10983826-10486973, http://linkedlifedata.com/resource/pubmed/commentcorrection/10983826-10555290, http://linkedlifedata.com/resource/pubmed/commentcorrection/10983826-1342920, http://linkedlifedata.com/resource/pubmed/commentcorrection/10983826-1398060, http://linkedlifedata.com/resource/pubmed/commentcorrection/10983826-15012383, http://linkedlifedata.com/resource/pubmed/commentcorrection/10983826-4585855, http://linkedlifedata.com/resource/pubmed/commentcorrection/10983826-7968486, http://linkedlifedata.com/resource/pubmed/commentcorrection/10983826-8335479, http://linkedlifedata.com/resource/pubmed/commentcorrection/10983826-8561471, http://linkedlifedata.com/resource/pubmed/commentcorrection/10983826-8593038, http://linkedlifedata.com/resource/pubmed/commentcorrection/10983826-8642610, http://linkedlifedata.com/resource/pubmed/commentcorrection/10983826-9244264, http://linkedlifedata.com/resource/pubmed/commentcorrection/10983826-9299222, http://linkedlifedata.com/resource/pubmed/commentcorrection/10983826-9367129, http://linkedlifedata.com/resource/pubmed/commentcorrection/10983826-9504992, http://linkedlifedata.com/resource/pubmed/commentcorrection/10983826-9812361, http://linkedlifedata.com/resource/pubmed/commentcorrection/10983826-9872768, http://linkedlifedata.com/resource/pubmed/commentcorrection/10983826-9873079, http://linkedlifedata.com/resource/pubmed/commentcorrection/10983826-9929382
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jul
pubmed:issn
0962-8452
pubmed:author
pubmed:issnType
Print
pubmed:day
22
pubmed:volume
267
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1423-31
pubmed:dateRevised
2009-11-18
pubmed:meshHeading
pubmed:year
2000
pubmed:articleTitle
Decay of mutualistic potential in aphid endosymbionts through silencing of biosynthetic loci: Buchnera of Diuraphis.
pubmed:affiliation
Department of Ecology and Evolutionary Biology, Center for Insect Science, University of Arizona, Tucson 85721, USA. jwernegreen@mbl.edu
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, U.S. Gov't, Non-P.H.S.