DNA metabarcoding mosquitoes
The ability to reliably identify mosquito species is a critical element of effective mosquito control operations in Florida. Distinguishing Florida’s ~80 mosquito species from one another requires training, experience, and up-to-date resources on morphological differences between mosquito species. Alternatives to traditional external morphology-based mosquito identification are available - molecular and bioinformatic tools that use DNA sequences to distinguish species.
DNA barcoding is a molecular technique that allows organisms to be identified exclusively through their DNA sequences. To identify species, a standardized DNA sequence, in animals, the DNA barcoding region of the cytochrome c oxidase subunit I gene (COI), is amplified by PCR and sequenced. The resulting sequence is then bioinformatically compared against a database of taxonomically identified reference COI sequences. Modern DNA sequencing technology allow DNA barcoding to be considerably upscaled. DNA metabarcoding is DNA barcoding combined with high-throughput, next generation sequencing. Metabarcoding can be used to rapidly and verifiably determine the species composition of a mixed biological sample, such as a bulk sample of mosquito specimens. These technologies have been widely used in other biodiversity assessment and environmental monitoring applications but have not yet been applied to mosquito surveillance in the United States.
In Florida, DNA metabarcoding can be used in mosquito surveillance to improve the efficiency of mosquito identification, making it possible to rapidly and affordably identify large numbers of mosquitoes, screen for pathogens or parasites, recognize cryptic species, detect exotic mosquito introductions, or identify vertebrate hosts, among other applications. Research at FMEL using metabarcoding is focused on developing metabarcoding and bioinformatic pipelines for identifying bulk mosquito samples, blood meal analysis, and pathogen screening.
Relevant publications:
Reeves, L.E., Gillett-Kaufman, J.L., Kawahara, A.Y., and Kaufman, P.E., 2018. Barcoding blood meals: New vertebrate-specific primer sets for assigning taxonomic identities to host DNA from mosquito blood meals. PLOS Neglected Tropical Diseases. (Forthcoming)
Reeves, L.E., Holderman, C.J., Gillett-Kaufman, J.L., Kawahara, A.Y., Kaufman, P.E., 2016. Maintenance of host DNA integrity in field-preserved mosquito (Diptera: Culicidae) blood meals for identification by DNA barcoding. Parasites and Vectors 9: 503. doi:10.1186/s13071-016-1791-z
Contact: Lawrence Reeves