title: Structure and organization of the mitochondrial DNA control region with tandemly repeated sequence in the Amazon ornamental fish.
abstract: Tandemly repeated sequences are a common feature of vertebrate mitochondrial DNA control regions. However, questions still remain about their mode of evolution and function. To better understand patterns of variation in length and to explore the existence of previously described domain, we have characterized the control region structure of the Amazonian ornamental fish Nannostomus eques and Nannostomus unifasciatus. The control region ranged from 1121 to 1142 bp in length and could be separated into three domains: the domain associated with the extended terminal associated sequences, the central conserved domain, and the conserved sequence blocks domain. In the first domain, we encountered a sequence repeated 10 times in tandem (variable number tandem repeat (VNTR)) that could adopt an "inverted repetitions" type structural conformation. The results suggest that the VNTR pattern encountered in both N. eques and N. unifasciatus is consistent with the prerequisites of the illegitimate elongation model in which the unequal pairing of the chains near the 5'-end of the control region favors the formation of repetitions.
authors.affiliation: Laboratório de Genética Animal, Instituto Nacional de Pesquisas da Amazônia, Coordenação de Pesquisas em Biologia Aquática, Av. André Araújo, 2936, Petrópolis, 69011-970 Manaus, AM, Brazil. leandra@inpa.gov.br
authors.forename: Maria Leandra
authors.initials: ML
authors.lastname: Terencio
authors.forename: Carlos Henrique
authors.initials: CH
authors.lastname: Schneider
authors.forename: Maria Claudia
authors.initials: MC
authors.lastname: Gross
authors.forename: Eliana
authors.initials: E
authors.lastname: Feldberg
authors.forename: Jorge Ivan Rebelo
authors.initials: JI
authors.lastname: Porto
mesh_terms: D000818:Animals; D001483:Base Sequence; D001938:Brazil; D060125:Characiformes / Q000235:genetics*; D004272:DNA, Mitochondrial / Q000737:chemistry / Q000235:genetics*; D019143:Evolution, Molecular; D018598:Minisatellite Repeats / Q000235:genetics*; D008928:Mitochondria / Q000235:genetics; D008969:Molecular Sequence Data; D010802:Phylogeny; D016415:Sequence Alignment; D017422:Sequence Analysis, DNA; D020080:Tandem Repeat Sequences / Q000235:genetics
chemical_list: D004272:DNA, Mitochondrial