Two novel gene orders and the role of light-strand replication in rearrangement of the vertebrate mitochondrial genome.
Two novel mitochondrial gene arrangements are identified in an agamid lizard and a ranid frog. Statistical tests incorporating phylogeny indicate a link between novel vertebrate mitochondrial gene orders and movement of the origin of light-strand replication. A mechanism involving errors in light-strand replication and tandem duplication of genes is proposed for rearrangement of vertebrate mitochondrial genes. A second mechanism involving small direct repeats also is identified. These mechanisms implicate gene order as a reliable phylogenetic character. Shifts in gene order define major lineages without evidence of parallelism or reversal. The loss of the origin of light-strand replication from its typical vertebrate position evolves in parallel and, therefore, is a less reliable phylogenetic character. Gene junctions also evolve in parallel. Sequencing across multigenic regions, in particular transfer RNA genes, should be a major focus of future systematic studies to locate novel gene orders and to provide a better understanding of the evolution of the vertebrate mitochondrial genome.
Macey
J R
JR
Department of Biology, Washington University, St. Louis, Missouri 63130, USA.
Larson
A
A
Ananjeva
N B
NB
Fang
Z
Z
Papenfuss
T J
TJ
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D017931:DNA Primers / Q000235:genetics; D004261:DNA Replication / Q000235:genetics; D004272:DNA, Mitochondrial / Q000235:genetics; D019143:Evolution, Molecular; D015321:Gene Rearrangement; D016678:Genome; D008116:Lizards / Q000235:genetics; D008969:Molecular Sequence Data; D005810:Multigene Family; D009690:Nucleic Acid Conformation; D010802:Phylogeny; D012348:RNA, Transfer, Asn / Q000737:chemistry / Q000235:genetics; D012350:RNA, Transfer, Cys / Q000737:chemistry / Q000235:genetics; D011898:Ranidae / Q000235:genetics; D012104:Reptiles / Q000235:genetics; D014714:Vertebrates / Q000235:genetics*
D017931:DNA Primers; D004272:DNA, Mitochondrial; D012348:RNA, Transfer, Asn; D012350:RNA, Transfer, Cys