Population genetics of Aedes albopictus in the port cities of Hainan Island and Leizhou Peninsula, China

Abstract

Background: Aedes albopictus is an important vector of arboviral diseases, transmitting yellow fever, dengue fever, chikungunya and Zika. Monitoring its population genetic diversity and genetic differentiation has become essential for the control of infectious disease epidemics, especially in the functional areas of ports of entry. Population genetic monitoring of Ae. albopictus in the port area can help in the monitoring of port mosquito invasions and establishing port sanitary and quarantine measures to prevent the introduction and transmission of vector-borne diseases.

Methods: Seventeen populations of Ae. albopictus were collected from five port cities on Hainan Island and the Leizhou Peninsula, 8 populations were collected from port areas, 4 from urban areas and 5 from rural areas. Nine microsatellite loci and the mitochondrial COI gene were used to study the population genetic diversity, population genetic structure and interpopulation gene flow of Ae. albopictus.

Results: The nine microsatellite loci used were highly polymorphic, with an average PIC value of 0.768. The UPGMA genetic tree, STRUCTURE barplot and PCoA analyses showed that the 17 Ae. albopictus populations could be divided into three genetic groups. All 17 populations showed high haplotype diversity (Hd = 0.8069-0.9678) and formed 133 distinct haplotypes. These haplotypes can be divided into four genetic clades, but they are not associated with the geographical distribution of Ae. albopictus. Fst and Nm showed strong gene flow and little differentiation among populations.

Conclusion: Ae. albopictus in port areas are not significantly different from urban and rural populations due to strong gene flow, which prevents differentiation and increases the genetic diversity of the populations. High genetic diversity facilitates mosquito adaptation to complex environmental changes, which is a challenge for vector-borne disease control in port areas.

Keywords: Ae. albopictus; Genetic diversity; Ports of entry.