Complete mitochondrial genome sequence of the polychaete annelid Platynereis dumerilii

摘要

Complete mitochondrial genome sequences are now available for 126 metazoans (see Boore 1999; Mitochondrial Genomics link at http://www.jgi.doe.gov), but the taxonomic representation is highly biased toward sampling of Arthropoda, Mollusca, Echinodermata, and especially Chordata. With few exceptions (see Wolstenholme 1992; Boore 1999), these are circular DNA molecules, about 16 kb in size, and they encode the same set of 37 genes. A variety of nonstandard names are sometimes used for animal mitochondrial genes (see Boore 1999 for gene nomenclature and a table of synonyms). Mitochondrial genome comparisons serve as a model of genome evolution. In this system, much smaller and simpler than that of the nucleus, are all of the same factors of genome evolution, where one may find tractable the changes in tRNA structure, base composition, genetic code, gene arrangement, etc. Furthermore, patterns of mitochondrial gene rearrangements are an exceptionally reliable indicator of phylogenetic relationships (Smith et al. 1993; Boore et al. 1995; Boore and Brown 1998, 2000; Boore, Lavrov, and Brown 1998; Dowton 1999; Stechmann and Schlegel 1999; Kurabayashi and Ueshima 2000; but see a discussion of identified homoplasies in Boore 2000). To these ends, we are further sampling the variation among major animal groups in features of their mitochondrial genomes.