Novel and Broadly Applicable Microsatellite Markers in Identified Chromosomes of the Philippine Dengue Mosquitoes, Aedes aegypti (Diptera: Culicidae)

Dengue is the leading arboviral infection in the Philippines. Its endemicity in the country is due to the presence of its primary mosquito vector, Aedes aegypti (L.). This species has limited microsatellite markers. This study characterized microsatellite markers screened in silico from intergenic regions of the updated reference genome of Ae. aegypti from Liverpool, U.K. Criteria for good markers are: polymorphic, inherited in a Mendelian codominant manner, no null alleles, selectively neutral, randomly associated, and broadly applicable across different regions. Genotypes were scored using ABI Peak Scanner and were screened for the presence of null alleles. Hardy-Weinberg equilibrium, linkage disequilibrium, and robustness of the markers were determined by GENEPOP using Ae. aegypti samples from selected highland and lowland sites (n = 30 each) in the Philippines and outgroups (Thailand and Vietnam). Mendelian codominant inheritance was examined using F1 offspring of Ae. aegypti family (n = 30 each) derived from samples collected from Cebu city highlands and Maramag, Bukidnon. From the 63 randomly selected markers, nine were polymorphic. Two markers (Aaeg1-3D of chromosome 1 and Aaeg3-4C of chromosome 3) satisfied all criteria, hence, are good broadly useful microsatellite markers. Two other markers (Aaeg2-2E of chromosome 2 and Aaeg3-2A of chromosome 3) met all criteria but deviated from Mendelian codominant inheritance. These new markers of the Philippine Ae. aegypti with their chromosomal locations relative to the other published markers are presented, and will ultimately be useful in a variety of population genetic studies of Ae. aegypti to protect the public health.