Análise e caracterização do genoma mitocondrial: um estudo de caso de Cyprinodon sp. e Arapaima gigas

Abstract

The advancement of next-generation sequencing technologies has enabled large-scale characterization of mitochondrial genomes across various species. However, even among fish — the group with the highest number of sequenced mitochondrial genomes — only 9.7% of valid species are represented in genetic databases. This gap limits conservation programs, which rely on genetic data to guide management strategies. The genus Cyprinodon, composed of several threatened species restricted to isolated habitats, is particularly vulnerable to habitat loss and interspecific hybridization. In this context, the present study aimed to sequence and characterize the mitochondrial genome of Cyprinodon sp., in order to clarify phylogenetic relationships and evolutionary aspects of the Cyprinodontidae family. The sample was sequenced using the Illumina HiSeq platform, assembled with Megahit software, and analyzed using tools such as MitoZ, Circos, ClustalW, MrBayes, and Figtree. The complete mitogenome comprises 16,500 bp and contains 37 genes. Concurrently, Arapaima gigas, an iconic Amazonian species historically important to fisheries, is currently threatened with extinction and classified as “Data Deficient” by the IUCN. In the Tocantins River, heavily impacted by human activities, fishers from 25 communities reported the near disappearance of the species, with only one recent sighting on Jaracuera Island. The disappearance of A. gigas has severe economic consequences for local communities. Without collaboration between fishery managers and local populations, the species faces an imminent risk of regional extinction, further exacerbated by the lack of data on its fishing dynamics in northern Brazil.