Mitogenomes of mosquito species of Harris County in Texas

Abstract

Harris County, Texas, remains at continuous risk to mosquito-borne diseases due to its geographic landscape and abundance of medically important mosquito vectors. Targeted mitigation of these mosquitoes requires accurate identification of these mosquitoes taxa. Currently, there is a paucity of genetic information to inform molecular identification and phylogenetic relationships beyond well-studied mosquito species. Here we utilized a genome skimming approach using shallow shot gun sequencing to generate data and assemble the mitochondrial genomes of 37 mosquito species collected in Harris County, Texas. This report includes the complete mitochondrial genome for 25 newly sequenced species spanning 10 genera; the genomes were consistent with reference genomes in the GenBank database having 37 genes (13 protein-coding, 2 rRNA and 22 tRNA), and average AT content of 78.74%. Bayesian and maximum likelihood tree topologies using just the easily aligned 13 concatenated protein coding genes confirmed phylogenetic placement of species for Aedes, Anopheles and Culex genera clustering in single clades as expected. Furthermore, this approach provided more robust phylogenetic placement/identity of study taxa when compared to the use of the traditional cytochrome oxidase I partial gene barcode sequence for molecular identification. This study demonstrates the utility of genome skimming as a cost-effective alternative approach to generate reference sequences for the validation of mosquito identification and taxonomic rectification, knowledge necessary for guiding targeted vector interventions.

Fig. 1

Structural representative of a mosquito mitochondrial genome of public health importance in Harris County, Texas. Culex tarsalis is usually captured at specific sites following flooding events. The teal, black and salmon color blocks represent the PCGs, tRNAs and rRNAs respectively.

Fig. 2

Phylogenetic tree for the 37 mosquito species from Harris County, Texas. Accession numbers starting with ‘PQ’ were sequenced in this study. Mitogenomes of the 25 species newly characterized are indicated with blue. The tree was constructed using the concatenated 13 PCGs using BEAST with the General Reversible Time (GTR + G + 1) model. Numbers at the nodes represent posterior probabilities based on Bayesian inferences.

Fig. 3

Phylogenetic reconstruction using Bayesian Inference based on A. concatenated 13 PCGS of Culex species mitogenomes sequenced in the study (asterisk) and 7 Culex mitogenomes from NCBI GenBank B. Extracted COI genes from Culex species sequenced in this study (asterisk) and COI regions from Culex species on GenBank repository.

Fig. 4

Sliding window analysis of protein coding genes among 8 Culex mosquito mitochondrial genomes sequenced in this study.

Fig. 5

Harris county entomology surveillance study sites This map was generated using the leaflet package(v.2.2.2) in R (v.4.2.1), with OpenStreetMap as a tile provider. Blue plots indicate locations of mosquito collections utilized for this study.