Culicidae evolutionary history focusing on the Culicinae subfamily based on mitochondrial phylogenomics

Abstract

Mosquitoes are insects of medical importance due their role as vectors of different pathogens to humans. There is a lack of information about the evolutionary history and phylogenetic positioning of the majority of mosquito species. Here we characterized the mitogenomes of mosquito species through low-coverage whole genome sequencing and data mining. A total of 37 draft mitogenomes of different species were assembled from which 16 are newly-sequenced species. We datamined additional 49 mosquito mitogenomes, and together with our 37 mitogenomes, we reconstructed the evolutionary history of 86 species including representatives from 15 genera and 7 tribes. Our results showed that most of the species clustered in clades with other members of their own genus with exception of Aedes genus which was paraphyletic. We confirmed the monophyletic status of the Mansoniini tribe including both Coquillettidia and Mansonia genus. The Aedeomyiini and Uranotaeniini were consistently recovered as basal to other tribes in the subfamily Culicinae, although the exact relationships among these tribes differed between analyses. These results demonstrate that low-coverage sequencing is effective to recover mitogenomes, establish phylogenetic knowledge and hence generate basic fundamental information that will help in the understanding of the role of these species as pathogen vectors.

Figure 1

Comparative map of mitogenomes sequenced in relation to Ae. aegypti mitochondrial genome (NC_010241.1).

Figure 2

Comparative map of mitogenomes characterized from SRA data in relation to Ae. aegypti mitochondrial genome (NC_010241.1).

Figure 3

Evolutionary timescale of Culicidae family. Tree was generated from BEAST using PCGs nucleotide sequences partitioned by gene and codon positions (1st + 2nd and 3rd separately). Blue bars represent the HPD95%. The numbers above and below the bars show the posterior probability and the predicted median dating respectively for each node. Specific words inside the circles represent the nodes discussed in the text. Light blue tip names represent mitogenomes characterized from SRA data. Orange tip names represent sequenced mitogenomes from this study.

Figure 4

Zoom on the Culicinae branch of Fig. 3 showing in more detail the evolutionary timescale of Culicinae subfamily. Tree was generated from BEAST analysis of partitioned PCG taking into account the split of codon positions (1st + 2nd and 3rd codon position separately). Blue bars in the nodes represent the HPD95%. The numbers above and below the bars show the posterior probability and the predicted median dating respectively for each node. Specific words inside the circles represent the nodes discussed in the text. Light blue tip names represent mitogenomes characterized from SRA data. Orange tip names represent sequenced mitogenomes from this study.

Figure 5

Bayesian inferred trees showing the incongruences in positioning of Aedeomyia, Uranotaenia and Toxorhynchites genera using different alignment datasets.