Mitogenomics of Culex pipiens Form Pipiens From the Turkish Black Sea Region Reveals Structural Conservation and...

The Culex pipiens complex includes major mosquito vectors involved in the transmission of West Nile virus and filarial nematodes. In Türkiye, particularly in the Black Sea region, members of this complex are widely distributed, yet mitogenome-scale data from local populations remain limited. Here, we sequenced, assembled, and annotated the complete mitochondrial genomes of five Culex pipiens form pipiens isolates collected from different provinces along the Turkish Black Sea coast. Following the current taxonomic interpretation, subspecies-level names were avoided, Cx. pallens was treated as a species, and molestus was treated as a form of Cx. pipiens. The newly generated mitogenomes were highly conserved, ranging from 15,602 to 15,604 bp, and each contained the typical set of 37 mitochondrial genes with a strong A + T bias (~78.2%). Comparative analyses showed a conserved gene order and a characteristic culicid mitogenome architecture. Expanded comparisons across the broader Cx. pipiens complex dataset showed that mitochondrial diversity was concentrated in selected loci, particularly COX1, ND2, COX3, CYTB, ND5, and 12S rRNA, as well as in terminal regions associated with the A + T-rich control region. Phylogenetic analyses based on the concatenated sequences of 13 mitochondrial protein-coding genes and two rRNA genes showed that the Turkish isolates do not form a single exclusive mitochondrial lineage, but are distributed across different parts of the ingroup together with other members of the Cx. pipiens complex, including Cx. pipiens form molestus, Cx. pallens, and Cx. quinquefasciatus. These findings support the view that mitochondrial genomes in this complex primarily reflect maternal lineage history and may be influenced by introgression and incomplete lineage sorting rather than sharply discrete taxonomic or form-level boundaries. Overall, the mitogenomic resources generated in this study provide a useful regional reference for future comparative and evolutionary studies of the Cx. pipiens complex.