Analyzing mosquito (Diptera: culicidae) diversity in Pakistan by DNA barcoding

PLoS One. 2014 May 14;9(5):e97268. doi: 10.1371/journal.pone.0097268. eCollection 2014.

Abstract

Background: Although they are important disease vectors mosquito biodiversity in Pakistan is poorly known. Recent epidemics of dengue fever have revealed the need for more detailed understanding of the diversity and distributions of mosquito species in this region. DNA barcoding improves the accuracy of mosquito inventories because morphological differences between many species are subtle, leading to misidentifications.

Methodology/principal findings: Sequence variation in the barcode region of the mitochondrial COI gene was used to identify mosquito species, reveal genetic diversity, and map the distribution of the dengue-vector species in Pakistan. Analysis of 1684 mosquitoes from 491 sites in Punjab and Khyber Pakhtunkhwa during 2010-2013 revealed 32 species with the assemblage dominated by Culex quinquefasciatus (61% of the collection). The genus Aedes (Stegomyia) comprised 15% of the specimens, and was represented by six taxa with the two dengue vector species, Ae. albopictus and Ae. aegypti, dominant and broadly distributed. Anopheles made up another 6% of the catch with An. subpictus dominating. Barcode sequence divergence in conspecific specimens ranged from 0-2.4%, while congeneric species showed from 2.3-17.8% divergence. A global haplotype analysis of disease-vectors showed the presence of multiple haplotypes, although a single haplotype of each dengue-vector species was dominant in most countries. Geographic distribution of Ae. aegypti and Ae. albopictus showed the later species was dominant and found in both rural and urban environments.

Conclusions: As the first DNA-based analysis of mosquitoes in Pakistan, this study has begun the construction of a barcode reference library for the mosquitoes of this region. Levels of genetic diversity varied among species. Because of its capacity to differentiate species, even those with subtle morphological differences, DNA barcoding aids accurate tracking of vector populations.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Biodiversity
  • Culicidae / genetics*
  • DNA Barcoding, Taxonomic / methods
  • DNA, Mitochondrial / genetics
  • Dengue / genetics
  • Disease Vectors
  • Genetic Variation / genetics*
  • Haplotypes / genetics
  • Insect Vectors / genetics
  • Pakistan
  • Phylogeography / methods

Substances

  • DNA, Mitochondrial

Grant support

This research was enabled by grant 106106-001, Engaging Developing Nations in the International Barcode of Life (iBOL) Project, from IDRC. Sequence analysis was enabled by a grant from the Government of Canada through Genome Canada and the Ontario Genomics Institute in support of iBOL. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.