title: Utility and evolution of cytochrome b in insects.
abstract: Cytochrome b (cyt-b) is widely used in molecular phylogenetic studies of vertebrate, but not invertebrate, taxa. To determine whether this situation is an historical accident or reflects the utility of cyt-b, we compared the abilities of cyt-b, COI, and one nuclear ribosomal gene region (D1 of 28S) to recover intergeneric relationships within the tiger moth tribes Ctenuchini and Euchromiini. Additionally, we compared the rate of sequence and amino acid evolution of cyt-b across insects. Cytochrome b had the same level of sequence variation and A/T bias as COI, but was less useful for recovering intergeneric relationships. The total evidence tree casts doubt on the traditional taxonomy of the group. For the class Insecta, we found that functional conservation of amino acids occurs for the same regions as those found in vertebrates with the exception of Mallophaga (lice). Lice have an accelerated rate of nonsynonymous substitutions. Accelerated rate of cyt-b nucleotide and amino acid evolution in Apidae (bees) may be correlated with increased metabolic rates associated with facultative endothermy (= heterothermy).
authors.affiliation: Department of Entomology, University of Minnesota, 219 Hodson Hall, 1980 Folwell Avenue, St. Paul, Minnesota 55108-6125, USA.
authors.forename: R B
authors.initials: RB
authors.lastname: Simmons
authors.forename: S J
authors.initials: SJ
authors.lastname: Weller
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D003573:Cytochrome b Group / Q000235:genetics*; D004247:DNA / Q000737:chemistry / Q000235:genetics; D003576:Electron Transport Complex IV / Q000235:genetics; D019143:Evolution, Molecular; D014644:Genetic Variation; D007313:Insecta / Q000145:classification / Q000235:genetics*; D008969:Molecular Sequence Data; D010802:Phylogeny; D012339:RNA, Ribosomal, 28S / Q000235:genetics; D016415:Sequence Alignment; D017422:Sequence Analysis, DNA; D017386:Sequence Homology, Amino Acid
chemical_list: D003573:Cytochrome b Group; D012339:RNA, Ribosomal, 28S; D004247:DNA; D003576:Electron Transport Complex IV