Investigating the Genetic Diversity of Culiseta longiareolata Populations in Southern Iran: Insights from the COI Gene.

Objective Culiseta longiareolata (Cs. longiareolata), a mosquito species found in Europe, Asia, and North Africa, is an important vector for various diseases like West Nile encephalitis, and malaria. This study aimed to assess the genetic diversity of the Cs. longiareolata mosquito population in Fars province, southern Iran due to the critical role of genetic diversity in shaping the adaptability and survival of mosquito populations and also adaptation of mosquitoes to environmental changes, insecticides, and pathogens.

Methods In this study, samples of Cs. longiareolata mosquitoes were collected from 12 locations in Fars province, Iran. Larval stages were collected using the dipping method, while adults were captured with aspirators and mosquito nets, then stored at -20 °C for later DNA extraction. The COI gene was amplified via polymerase chain reaction (PCR) for genetic analysis. The sequencing was done by Bioneer Company in South Korea, and the results were analyzed using bioinformatics tools like Chromas, ClustalW2, and MEGA7. The final sequences were registered in GenBank for further analysis.

Results The phylogenetic analysis using the maximum likelihood method revealed that Cs. longiareolata samples from Iran clustered with populations from various countries. The analysis involved 17 nucleotide sequences with 504 positions, using the Tamura-Nei model. The genetic diversity index was 0.0165, with 6 haplotypes and a haplotype diversity of 0.721. Demographic expansion indices suggested a potential expansion event in the population. A total of 274 mosquitoes were collected, with 18 examined by PCR and 6 sequenced for the study.

Conclusion This study provides the first comprehensive genetic assessment of Cs. longiareolata populations in southern Iran using the COI gene which contributes valuable baseline data for future molecular and ecological studies. The findings reveal a moderate level of genetic diversity and clear genetic connections with Mediterranean and Middle Eastern populations, highlighting possible regional gene flow. The research highlights the significance of genetic diversity in comprehending mosquito dynamics and enhancing disease control efforts. Ongoing genetic monitoring is essential for managing vector-borne diseases.