No abstract

Vertebrate mitochondrial genomes have been extensively studied for genetic and evolutionary purposes, these are normally believed to be extremely conserved, however, different cases of gene rearrangements have been reported. To verify the level of rearrangement and the mitogenome evolution, we performed a comparative genomic analysis of the 2831 vertebrate mitochondrial genomes representing 12 classes available in the NCBI database. Using a combination of bioinformatics methods, we determined there is a high number of errors in the annotation of mitochondrial genes, especially in tRNAs. We determined there is a large variation in the proportion of rearrangements per gene and per taxonomic class, with higher values observed in Actinopteri, Amphibia and Reptilia. We highlight that these are results for currently available vertebrate sequences, so an increase in sequence representativeness in some groups may alter the rearrangement rates, so in a few years it would be interesting to see if these rates are maintained or altered with the new mitogenome sequences. In addition, within each vertebrate class, different patterns in rearrangement proportion with distinct hotspots in the mitochondrial genome were found. We also determined that there are eleven convergence events in gene rearrangement, nine of which are new reports to the scientific community.

No abstract

The evolution of the vertebrate mitochondrial genome has been the focus of numerous genetic and evolutionary studies over the last several decades. Initially, sampling was heavily biased toward taxonomic orders of greatest economic or health importance, but recent advances in DNA sequencing technology have facilitated a much broader phylogenetic sampling from which we can clarify general evolutionary trends such as patterns of gene rearrangement. Toward this end, we performed a comparative genomic analysis of the 2,831 vertebrate mitochondrial genomes representing 12 classes that are available in the NCBI database. Using a combination of bioinformatics methods, we determined that there is a great variation in the proportion of rearrangement by gene and by taxonomic class, with higher rates being observed in Reptilia, Amphibia, Petromyzonti, Mammalia, and Actinopteri. Further, within each class, there is large variation in proportion of reorganization among different orders or even taxonomic families. Eleven events of convergence in the genic order among different taxonomic orders were determined, most of them not previously reported.