Genetic Diversity Of Aedes Albopictus In China

Aedes albopictus, also called Asia tiger mosquito, originated in Asia. In its native range, Ae. albopictus is distributed from Indonesia in the south, India in the west, to Japan and Korea in the north and east, covering the most of eastern China. Ae. albopictus has now expanded to over 70 countries which span tropical, subtropical and temperate zones, including North America, South America, Europe and Africa, Madagascar, northern part of Australia and Papua New Guinea. Nowadays the migration and dispersal of Ae. albopicuts have drawn public health attention. Ae. albopictus has been listed as one of the world’s 100 worst invasive alien species (ISSG.org). It is an important arbovirus vector that transmits many diseases, such as dengue fever, chikungunya fever, yellow fever and so on.This study examined the genetic diversity of Ae. albopictus in China, including population genetic structure and genetic diversity, in order to provide knowledge for risk assessment and prediction of related infection diseases. For genetic analysis, mitochondrial COI gene sequences and seven microsatellite makers were employed in the study. The results are as follows:(1) Both mitochondrial COI gene and seven microsatellite makers showed high genetic differences among Ae. albopictus populations from different geographical regions in China. For the COI gene, the mean haplotype diversity (Hd) of Ae. albopictus in China was 0.87541; the nucleotide diversity(π) was 0.00185. For the seven microsatellite markers, the observed heterozygosity (Ho) within populations ranged from 0.390 to 0.795; the expected heterozygosis (He) were from 0.460 to 0.700. The number of alleles per population was from 5.000 to 10.857. Higher genetic diversity and genetic differentiation were observed in populations of Hainan and Yunnan Provinces, compared to those in other regions.(2) Seven microsatellite primers were used to genotype 672 Ae. albopictus specimens from 21 populations. The result showed that all microsatellite loci were highly polymorphic. Yet most loci deviated from Hardy-Weinberg equilibrium in most populations, which implied the allele frequency variation between generations and possible occurrence of migration, mutation or selection.(3) Both mitochondrial COI gene and seven microsatellite makers revealed the close relationship between climatic zones and the population structure of Ae. albopictus. The high within population genetic diversity and among population differentiations in Hainan and Yunnan Provinces likely benefited from the diverse natural habitats and the warm and humid climates in these regions.(4) The genetic distances and phylogenetic trees of Ae. albopictus showed that populations of Hainan, Yunnan, Guangxi and Tibet Provinces or Regions were more closely related to each other, while those in the north of Guangdong Province were more similar. This result agrees with the two different climatic zones that the two groups separately occupied.Mitochondrial COI gene and seven microsatellite makers were used to examine the genetic diversity of Ae. albopictus in China, and the relationship between genetic structure and climatic zones. These results laid the foundation to further study the Ae. albopictus populations and relate risk of disease transmission.