RESUMO
Molecular identification is very useful in cases where morphology-based species identification is not possible. Examples for its application in cetaceans include the identification of carcasses of stranded animals in advanced state of decomposition and body parts that are illegally traded. One DNA region that is often used for molecular identification is the Folmer region of the mitochondrial gene cytochrome c oxidase subunit I (COI) (locus 48 to 705 bp). This locus has been used for the identification of several animal species, including whales and dolphins. The goal of the present study was to evaluate the usefulness of another region of COI, the E3-I5 (locus 685 to locus 1179; 495 bp) as a marker for identification of cetaceans from northeastern Canada and northeastern Brazil. The identification markers were successfully obtained for seven cetacean species after performing percent identity and Basic Local Alignment Search Tool analyses. The obtained markers are now publicly available and are useful for the identification of the endangered blue whale (Balaenoptera musculus), common minke whale (B. acutorostrata), vulnerable sperm whale (Physeter macrocephalus), harbor porpoise (Phocoena phocoena), common bottlenose dolphin (Tursiops truncatus), Guiana dolphin (Sotalia guianensis), and melon-headed whale (Peponocephala electra).
Assuntos
Cetáceos/genética , Código de Barras de DNA Taxonômico/normas , Complexo IV da Cadeia de Transporte de Elétrons/genética , Alinhamento de Sequência/normas , Animais , Cetáceos/classificação , Código de Barras de DNA Taxonômico/métodos , Espécies em Perigo de Extinção , Marcadores Genéticos , Padrões de Referência , Alinhamento de Sequência/métodosRESUMO
Endangered angelsharks and a protected dolphin species are illegally traded in Brazil. In this study, we determined prospective molecular markers for detecting these species in the trade of angelshark carcasses and 'dolphin' eyeball amulets. We compiled publicly available as well as new and unpublished cytochrome b (cyt b) DNA sequences for species involved in these trades. These sequences were digested in silico using restriction enzymes. We then described prospective polymerase chain reaction (PCR)-restriction fragment length polymorphism markers for distinguishing between protected species and the species whose trade was legally allowed in these two trade groups. The prospective marker for identifying angelshark carcasses consists of cyt b PCR and digestion by BstXI, BsgI, BspMI, BsrDI, and HaeII restriction enzymes. The prospective marker for identifying eyeball amulets consists of cyt b PCR and digestion by ApoI, BtsI, HindII, BsaAI, BplI, and SspI restriction enzymes. This is the first study to deposit in GenBank cyt b sequences for the angelshark species Squatina argentina, Squatina guggenheim, and Squatina occulta. Moreover, the S. argentina haplotype is the first DNA sequence for this species deposited in GenBank.
Assuntos
Citocromos b/genética , Golfinhos/genética , Espécies em Perigo de Extinção , Proteínas de Peixes/genética , Tubarões/genética , Animais , Sequência de Bases , Brasil , Conservação dos Recursos Naturais , Enzimas de Restrição do DNA/química , Enzimas de Restrição do DNA/metabolismo , Golfinhos/classificação , Haplótipos , Dados de Sequência Molecular , Polimorfismo de Fragmento de Restrição , Tubarões/classificaçãoRESUMO
Two dates of publication have been associated with the hidden angelshark Squatina occulta. Additionally, the name of the second author of this species has been cited with different spellings in different publications. Both inconsistencies are addressed in this study. It is suggested that the hidden angelshark be consistently cited as Squatina occulta Vooren & da Silva 1991.
Assuntos
Editoração , Tubarões/classificação , Animais , Autoria , Terminologia como AssuntoRESUMO
We investigated a reported case of stingray Dasyatis americana misidentification not detected in a published study using the random amplified polymorphic DNA (RAPD) technique. If the referred specimen (landed by fisheries in Ceará, northeastern Brazil) was misidentified (as Dasyatis centroura) in the field, why did its RAPD data fail to clarify the mistake? Was it due to limitations of RAPD markers or perhaps to a taxonomic issue? Contrary to our initial expectations, neither of these hindered the detection of the misidentification. After reanalyzing the primary genetic data associated with the misidentified specimen (PCR gel photographs and/or matrices of presence/absence of markers for six RAPD primers), we found that the RAPD markers were sufficient to correctly assign the misidentified specimen to its proper species identity. In the original study, the specimen misidentification was neither noticed by the authors nor apparent in the published article due to how their results were interpreted and presented.