Abstract
BackgroundAedes (Stegomyia) albopictus (Skuse) is an indigenous species and the predominant vector of dengue fever in China. Understanding of genetic diversity and structure of the mosquito would facilitate dengue prevention and vector control. Sympatric cryptic species have been identified in the Ae. albopictus subgroup in Southeast Asia; however, little is known about the presence and distribution of cryptic species in China. This study aimed to examine the genetic diversity, evaluate potential new cryptic sibling species, and assess the prevalence of Wolbachia infections in field populations.MethodsAedes adult female specimens were collected from five provinces in southern and central China during 2015–2016. Morphological identification was performed under dissection microscope. The mitochondrial DNA cytochrome c oxidase subunit 1 (cox1, DNA barcoding) locus and the ribosomal DNA internal transcribed spacer region 2 (ITS2) marker were used to examine the genetic variation, evaluate cryptic sibling species, and population structure in the field populations. Screening for the presence of Wolbachia was performed using multiplex PCR.ResultsA total of 140 individual specimens with morphological characteristics similar to Ae. albopictus were sequenced for DNA barcoding. Among these, 129 specimens (92.1%) were confirmed and identified as Ae. albopictus. The remaining 11 specimens, from 2 provinces, were identified as 2 distinct sequence groups, which were confirmed by ITS2 marker sequencing, suggesting the existence of potential cryptic species of Ae. albopictus. In Ae. albopictus, we found significant genetic differentiation and population structure between populations collected from different climate zones. Medium to high frequencies of Wolbachia infections were observed in natural Ae. albopictus populations, whereas Wolbachia was infrequent or absent in cryptic species populations.ConclusionsOur findings highlight the population differentiation by climate zone and the presence of novel, cryptic Aedes species in China. The low prevalence of Wolbachia infections in cryptic species populations could reflect either a recent invasion of Wolbachia in Ae. albopictus or different host immune responses to this symbiont in the cryptic species. The study provides useful information for vector control and host-symbiont coevolution. Further study is needed to investigate the potential for arbovirus infection and disease transmission in the emerged cryptic species.
Highlights
Aedes (Stegomyia) albopictus (Skuse) is an indigenous species and the predominant vector of dengue fever in China
Since there is only one individual of Ae. albopictus in GX-WZ population and one each of Aedes sp. from HN-BS, and HN-BT populations, which is insufficient for population genetic analysis, these individuals were excluded from the analysis of the population genetic structure and genetic diversity
Our results indicated that the genetic diversity and population structure of Ae. albopictus between tropical, subtropical and temperate zones in China appeared to be separated by a single mutation step at the mitochondrial DNA barcoding cox1 gene
Summary
Aedes (Stegomyia) albopictus (Skuse) is an indigenous species and the predominant vector of dengue fever in China. More than 11 sibling species or cryptic species have been identified and characterized in the Aedes albopictus subgroup of the Scutellaris group in the subgenus Stegomyia of Aedes [1,2,3]. Of these species, Ae. albopictus, originating from Asia, is the most widely distributed and has invaded on every continent except Antarctica [4, 5]. Aedes albopictus mosquitoes are regarded as the sole vector for dengue transmission in most these epidemics [14, 18]
Sign-in/Register to view highlights & summary 
Published Version (
Free)
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
