Comparative genomics of large mitochondria in placozoans

The first sequenced mitochondrial genome of a placozoan, Trichoplax adhaerens, challenged the conventional wisdom that a compact mitochondrial genome is a common feature among all animals. Three additional placozoan mitochondrial genomes representing highly divergent clades have been sequenced to de...

Full description

Saved in:
Bibliographic Details
Published in:PLoS genetics 2007-01, Vol.3 (1), p.e13-e13
Main Authors: Signorovitch, Ana Y, Buss, Leo W, Dellaporta, Stephen L
Format: Article
Language:English
Subjects:
Amino Acid Sequence
Animals
Chromosome Mapping
Comparative analysis
DNA, Mitochondrial - genetics
Evolutionary Biology
Exons - genetics
Genes
Genetic aspects
Genetics
Genome - genetics
Genomics
Identification and classification
Introns - genetics
Invertebrates - cytology
Invertebrates - genetics
Marine invertebrates
Metazoa
Microbiology
Mitochondria
Mitochondria - genetics
Mitochondrial DNA
Molecular Biology
Molecular Sequence Data
Phylogeny
Proteins - chemistry
Trichoplax adhaerens
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:The first sequenced mitochondrial genome of a placozoan, Trichoplax adhaerens, challenged the conventional wisdom that a compact mitochondrial genome is a common feature among all animals. Three additional placozoan mitochondrial genomes representing highly divergent clades have been sequenced to determine whether the large Trichoplax mtDNA is a shared feature among members of the phylum Placozoa or a uniquely derived condition. All three mitochondrial genomes were found to be very large, 32- to 37-kb, circular molecules, having the typical 12 respiratory chain genes, 24 tRNAs, rnS, and rnL. They share with the Trichoplax mitochondrial genome the absence of atp8, atp9, and all ribosomal protein genes, the presence of several cox1 introns, and a large open reading frame containing an intron group I LAGLIDADG endonuclease domain. The differences in mtDNA size within Placozoa are due to variation in intergenic spacer regions and the presence or absence of long open reading frames of unknown function. Phylogenetic analyses of the 12 respiratory chain genes support the monophyly of Placozoa. The similarities in composition and structure between the three mitochondrial genomes reported here and that of Trichoplax's mtDNA suggest that their uncompacted state is a shared ancestral feature to other nonmetazoans while their gene content is a derived feature shared only among the Metazoa.
ISSN:1553-7390
1553-7404
DOI:10.1371/journal.pgen.0030013