Mitogenomics of Central American weakly-electric fishes

• Published in: Gene Vol. 686; pp. 164 - 170
• Main Authors: Aguilar, Celestino, Miller, Matthew J., Loaiza, Jose R., Krahe, Rüdiger, De León, Luis F.
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 20.02.2019
• Subjects: Animals; Cytochromes b - genetics; Electric Fish - classification; Electric Fish - genetics; Fish Proteins - genetics; Gymnotiformes; Intergenic spacer; Metagenome; Mitogenome; Next generation sequencing; Panama; Phylogeny; Val; Ser; Ile; Aps; BI; Gln; Phe; Pro; Glu; COI-III; ND1–6 and ND4L; Trp; Gly; Panama; Cys; Asn; ML; Thr; tRNA; rRNA; Lys; 16S and 12S; Tyr; Next generation sequencing; ATP6 and ATP8; His; PCG; mitogenome; Intergenic spacer; Ala; Arg; CYTB; NCR; Gymnotiformes; Leu; Met; Mitogenome
• ISSN: 0378-1119; 1879-0038
• DOI: 10.1016/j.gene.2018.11.045

Electric fishes are a diverse group of freshwater organisms with the ability to generate electric organ discharges (EODs) that are used for communication and electrolocation. This group (ca. 200 species) has originated in South America, and six species colonized the Central American Isthmus. Here, we assembled the complete mitochondrial genomes (mitogenomes) for three Central American electric fishes (i.e. Sternopygus dariensis, Brachyhypopomus occidentalis, and Apteronotus rostratus), and, based on these data, explored their phylogenetic position among Gymnotiformes. The three mitogenomes show the same gene order, as reported for other fishes, with a size ranging from 16,631 to 17,093 bp. We uncovered a novel 60 bp intergenic spacer (IGS) located between the COII and tRNALys genes, which appears to be unique to the Apteronotidae. Furthermore, phylogenetic relationships supported the traditional monophyly of Gymnotiformes, with the three species positioned within their respective family. In addition, the genus Apteronotus belongs to the early diverging lineage of the order. Finally, we found high sequence divergence (13%) between our B. occidentalis specimen and a sequence previously reported in GenBank, suggesting that the prior mitogenome of B. occidentalis represents a different South American species. Indeed, phylogenetic analyses using Cytochrome b gene across the genus placed the previously reported individual within B. bennetti. Our study provides novel mitogenome resources that will advance our understanding of the diversity and phylogenetic history of Neotropical fishes. •The mitochondrial genomes of Apteronotus rostratus, Brachyhypopomus occidentalis and Sternopygus dariensis are sequenced and characterized.•A novel 60 bp intergenic spacer located between COII and tRNALys is reported for the first time in Gymnotiformes, and it may be unique to Apteronotus.•Phylogenetic analyses support the position of Central American weakly-electric fishes within the monophyletic Gymnotiformes.•Genetic analyses indicate that the mitogenome of B. occidentalis (AP011570) reported previously belongs to a different South America species.