Background Aedes albopictus is an indigenous and primary vector for Dengue and Zika viruses in China. Compare with its insecticide resistance, biology, and vector competence; little was known about its genetic variation, corresponding to environmental variations. Thus, the present study aims to discuss how Ae. albopictus population varies among different temperatures regions of China and decipher its potential dispersal patterns.
Methods The genetic variation and population structure of all 17 Ae. albopictus populations, collected from three temperature regions of China, were investigated with 11 microsatellite loci and mitochondrial COI gene.
Results 11 pairs out of 44 isolated microsatellite markers were chosen for genotyping analysis with the average PIC value of 0.713, which was high polymorphism. The number of alleles was high for each population, with the ne value increased from the Temperate region (3.876) to the Tropical region (4.144). 25 COI Haplotypes were detected, and the highest diversity was observed among the Tropical region. The mean Ho value (ca. 0.557) of all temperature regions, was significantly lower than the mean He values (ca. 0.684), with nearly all populations significantly departed from the HWE test and displayed significant population expansion ( p-value < 0.05).Two genetically isolated groups and three Haplotype clades were evaluated via STRUCTURE and Haplotype phylogenetic analyses, with Tropical populations isolated from other regions, significantly. Meanwhile, the majority genetic variation of Ae. albopictus populations were detected within populations and individuals at 31.40% and 63.04%, respectively, via AMOVA test, and a relatively significant positive correlation was merely observed among populations from the temperate region via Isolation by distance (IBD) analysis (R2 = 0.6614, p = 0.048). Recent dispersions were observed among different Ae. albopictus populations and a total of four major migration trends were rebuilt between the Tropical and the other two regions with the high genetic flows (Nm>0.5). Environmental factors, especially temperature and rainfall, may be the leading cause of genetic diversity differences of different temperature regions.
Conclusions Continuous dispersion contributes to the similarity of Ae. albopictus populations among different temperature regions, and environmental factors, especially temperature and rainfall, may be the leading cause of genetic variation.