Seventeen new complete mtDNA sequences reveal extensive mitochondrial genome evolution within the Demospongiae.

ABSTRACT: Two major transitions in animal evolution--the origins of multicellularity and bilaterality--correlate with major changes in mitochondrial DNA (mtDNA) organization. Demosponges, the largest class in the phylum Porifera, underwent only the first of these transitions and their mitochondrial genomes display a peculiar combination of ancestral and animal-specific features. To get an insight into the evolution of mitochondrial genomes within the Demospongiae, we determined 17 new mtDNA sequences from this group and analyzing them with five previously published sequences. Our analysis revealed that all demosponge mtDNAs are 16- to 25-kbp circular molecules, containing 13-15 protein genes, 2 rRNA genes, and 2-27 tRNA genes. All but four pairs of sampled genomes had unique gene orders, with the nu

SUBMITTER: Wang X 

PROVIDER: S-EPMC2444032 | biostudies-literature | 2008 Jul

REPOSITORIES: biostudies-literature