Linked Life Data

11961110

Source:http://linkedlifedata.com/resource/pubmed/id/11961110

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
5
pubmed:dateCreated
2002-4-18
pubmed:databankReference
pubmed:abstractText
We present the first molecular phylogenetic examination of the evolutionary position of retortamonads, a group of mitochondrion-lacking flagellates usually found as commensals of the intestinal tracts of vertebrates. Our phylogenies include small subunit ribosomal gene sequences from six retortamonad isolates-four from mammals and two from amphibians. All six sequences were highly similar (95%-99%), with those from mammals being almost identical to each other. All phylogenetic methods utilized unequivocally placed retortamonads with another amitochondriate group, the diplomonads. Surprisingly, all methods weakly supported a position for retortamonads cladistically within diplomonads, as the sister group to Giardia. This position would conflict with a single origin and uniform retention of the doubled-cell organization displayed by most diplomonads, but not by retortamonads. Diplomonad monophyly was not rejected by Shimodaira-Hasegawa, Kishino-Hasegawa, and expected likelihood weights methods but was marginally rejected by parametric bootstrapping. Analyses with additional phylogenetic markers are needed to test this controversial branching order within the retortamonad + diplomonad clade. Nevertheless, the robust phylogenetic association between diplomonads and retortamonads suggests that they share an amitochondriate ancestor. Because strong evidence indicates that diplomonads have secondarily lost their mitochondria (rather than being ancestrally amitochondriate), our results imply that retortamonads are also secondarily amitochondriate. Of the various groups of eukaryotes originally suggested to be primitively amitochondriate under the archezoa hypothesis, all have now been found to have physical or genetic mitochondrial relics (or both) or form a robust clade with an organism with such a relic.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
May
pubmed:issn
0737-4038
pubmed:author
pubmed:issnType
Print
pubmed:volume
19
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
777-86
pubmed:dateRevised
2009-11-19
pubmed:meshHeading
pubmed:year
2002
pubmed:articleTitle
Retortamonad flagellates are closely related to diplomonads--implications for the history of mitochondrial function in eukaryote evolution.
pubmed:affiliation
Department of Microbiology, Immunology, and Molecular Genetics, University of California at Los Angeles, 1602 Molecular Sciences Building, 405 Hilgrad Avenue, Los Angeles, CA 90095, USA. jsilber@ucla.edu.4
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, U.S. Gov't, Non-P.H.S., Research Support, Non-U.S. Gov't