🧬 genomics

Complete mitochondrial genomes of Arizona West Nile virus vectors, Culex quinquefasciatus and Culex tarsalis

This study reports the first complete mitochondrial genomes of West Nile virus vectors *Culex quinquefasciatus* and *Culex tarsalis* from Arizona, utilizing a novel long-range PCR and Pacific Biosciences HiFi sequencing method to reveal unique genomic features and establish a new approach for global vector population surveillance.

Original authors: Barrand, Z. A., Ridenour, C. L., Erickson, D. E., Rivas, A. N., Schmidt, B. K., Will, J., Young, S. J., Busser, N., Townsend, J., Enriquez, D., Murphy, D., Wong, S., Keats, J., Carvalho, S. T., Attard

Published 2026-08-21

📖 1 min read☕ Coffee break read

CC BY 4.0

Original authors: Barrand, Z. A., Ridenour, C. L., Erickson, D. E., Rivas, A. N., Schmidt, B. K., Will, J., Young, S. J., Busser, N., Townsend, J., Enriquez, D., Murphy, D., Wong, S., Keats, J., Carvalho, S. T., Attardo, G. M., Barker, C. M., Hepp, C. M.

Original paper licensed under CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/). ⚕️ This is an AI-generated explanation of a preprint that has not been peer-reviewed. It is not medical advice. Do not make health decisions based on this content. Read full disclaimer

Technical Summary

Problem
West Nile virus (WNV) has imposed a substantial burden on Maricopa County, Arizona, over the past decade. The primary vectors responsible for spillover to human populations in this region are Culex quinquefasciatus and Culex tarsalis. Despite their medical importance, there is a critical need to better understand the distribution of these vector populations over time and space. A specific gap exists in the availability of complete, annotated mitochondrial genomes for these species originating from Arizona, which limits the ability to conduct precise population-level surveillance.

Methodology
This study introduces and applies a newly developed methodological pipeline designed to overcome challenges in sequencing complex vector genomes. The approach combines long-range polymerase chain reaction (PCR) with long-read Pacific Biosciences (PacBio) HiFi sequencing. This technique was utilized to successfully generate two full-length, annotated mitochondrial genomes from Culex quinquefasciatus and Culex tarsalis specimens collected in Maricopa County, Arizona. The study further employed maximum likelihood-based phylogenetic reconstruction to validate the species designation of the newly sequenced genomes.

Key Results
The application of this methodology yielded two distinct mitochondrial genomes:

Culex quinquefasciatus: The circular mitogenome is 15,587 bp in length. Notably, this represents the first USA-based mitogenome for this species to be sequenced through the AT-rich control region.
Culex tarsalis: The mitochondrial genome is 16,416 bp long, exceeding the length of recently published mitogenomes from California (CTarK1) and Texas (PQ585801). The increased length is attributed to a specific 905 bp insertion within the AT-rich control region, a feature not present in other publicly available mitogenomes for this species.

Phylogenetic analysis based on maximum likelihood reconstruction supports the correct species designation for both newly sequenced mitogenomes.

Significance and Claims
The paper claims that this study provides the first West Nile virus vector mitochondrial genomes sequenced from Arizona. By establishing these genomic resources, the work addresses the immediate need for better tools to track vector distribution. The authors assert that the newly developed methodology offers a unique approach for studying medically important vector species globally. Furthermore, the study positions this technique as a viable solution for integrating population studies into pooled vector pathogen surveillance programs, thereby enhancing the capacity to monitor vector-borne disease risks.

More like this