Mem Inst Oswaldo Cruz, Rio de Janeiro, VOLUME 121 | 2026
Research Articles
Mitochondrial genomes and phylogeny of Atratus and Educator Group species of the Melanoconion Section of Culex (Melanoconion) (Diptera: Culicidae)
1Universidade de São Paulo, Faculdade de Saúde Pública, Departamento de Epidemiologia, São Paulo, SP, Brasil
2Natural History Museum, Department of Life Sciences, London, United Kingdom
DOI: 10.1590/0074-02760250125
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ABSTRACT
BACKGROUND Culex (Melanoconion) species are known to act as vectors for different arboviruses, and little is known about the mitochondrial genome of these species.
OBJECTIVES Aiming to expand the genetic knowledge of this subgenus, a 12Kb fragment of the mitochondrial genome was sequenced from 23 specimens belonging to the Atratus and Educator Groups of the subgenus Melanoconion of Culex.
METHODS The sequenced specimens were morphologically identified as Culex dunni, Culex ensiformis, Culex theobaldi, Culex trigeminatus, Culex eknomios, Culex zeteki, Culex near commevynenis, Culex angularis, Culex longistriatus, and Culex near vaxus. The reads were assembled with the reference genome of Culex quinquefasciatus and MITOS2 was used for gene annotation. Values of guanine-cytosine (GC) and adenine-thymine (AT) skews, nucleotide diversity, ratio between non-synonymous (Ka) and synonymous (Ks) substitution, and nucleotide composition were calculated, and phylogenetic analysis was performed.
FINDINGS As in other Culex mitogenomes, the partial mitochondrial genomes include 12 protein coding genes (PCGs), 15 tRNA, and 1 rRNA (rrnL). The PCGs showed no length variation between the species studied. ND5 gene presented one less base in the new sequences, which generated a stop codon and, consequently, a shorter length in relation to the Cx. quinquefasciatus sequence reference. All specimens showed a positive value for AT-skew and negative for GC-skew. Nucleotide diversity varied between 0.00407 and 0.12085. Ka/Ks values ranged from 0.0 to 2.775.
MAIN CONCLUSIONS Leucine and Serine were the most abundant amino acids. Phylogenetic analysis suggested three putative species.
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Financial support: FAPESP, CNPq (grants 2014/26229-7 and 303382/2022-8, respectively, to MAMS).
+ Corresponding author: porangaba@usp.br | 
https://orcid.org/0000-0003-0069-6848
Received 16 May 2025
Accepted 14 October 2025
HOW TO CITE
Oliveira TMP, Foster PG, Sá ILR, Sallum MAM. Mitochondrial genomes and phylogeny of Atratus and Educator Group species of the Melanoconion Section of Culex (Melanoconion) (Diptera: Culicidae). Mem Inst Oswaldo Cruz. 2025; 120: e250125.
HANDLING EDITOR
Ademir de Jesus Martins Jr | https://orcid.org/0000-0001-5739-1215
