The Phylogenetic Utility of the Mitochondrial Cytochrome b Gene for Inferring Relationships among Actinopterygian Fishes

Phylogenetic relationships of glyptosternoid fishes (Siluriformes: Sisoridae) inferred from mitochondrial cytochrome b gene sequences

“…Comparing to characiformes and cypriniformes, three deletion bases (coding for two amino acids) were found within this gene (also see Peng et al, 2002), from 14,757 to 14,759 (numbering is according to the human mtDNA sequences, Anderson et al, 1981). Mean base composition in cytochrome b gene sequences was similar to those previously reported for Actinopterygian fish (Cantatore et al, 1994;Lydeard and Roe, 1997), with low G content (13.4%) and almost equal A, T, and C content (29.3, 28.1, 29.2%, respectively). Strong bias in base composition is a feature typical of the cytochrome b gene and the other mitochondrial protein-coding genes (Irwin et al, 1991).…”

“…This incongruence may be caused by less informative sites in the 333 bp DNA sequences. Among the molecular markers, mitochondrial DNA (mtDNA) cytochrome b gene is a well-known protein-coding marker (Irwin et al, 1991) commonly used to reconstruct phylogenetic relationships, particularly, inter-or intra-specific relationships (e.g., Johnson and Jordan, 2000;Near et al, 2000), and it is also used to higher-level phylogeny (e.g., Lydeard and Roe, 1997). It is also considered a good gene for phylogenetic performance (Miya and Nishida, 2000;Zardoya and Meyer, 1996).…”

Are all fishes ancient polyploids?

“…explanation is that all these 'old' paralogs originated by an ancient genome duplication, somewhere between 300 and 450 million years ago (Taylor et al, 2001a). Because major teleost lineages are believed to have arisen between approximately 100 and 200 million years ago (Carroll, 1997;Lydeard and Roe, 1997), the working hypothesis was to assume that the genome duplication occurred in the ancestor of most (if not all) ray-finned fish. To find additional evidence, we compiled many vertebrate data sets, including the zebrafish genes described previously (Taylor et al, 2001a) and, when available, their pufferfish homologs.…”

Forensics: Food Authentication Using MtDNA

“…Cyt b is perhaps the best studied of all mitochondrial genes, particularly for fishes [79]. The gene has both conserved and variable regions, and has proven to be useful for investigating relationships of both closely and distantly related species.…”

“…The gene has both conserved and variable regions, and has proven to be useful for investigating relationships of both closely and distantly related species. Studies of cyt b sequence variation have shown this region to be well adapted for studying evolutionary relationships in Actinopterygian fishes [79]. Cyt b of respiratory chain is found only in the mitochondria of higher animals and plants [80] and cyt b is the only one encoded by the mitochondrial genome [62] among the 9-10 proteins that make up complex III of the mitochondrial oxidative phosphorylation system [61].…”