Microsatellite polymorphism in Anopheles maculatus, a malaria vector in Thailand

Dinucleotide microsatellites were characterized from Anopheles maculatus, a species of mosquito that transmits malaria. A partial genomic library of An. maculatus, consisting of 3,960 kilobases (kb), was screened with either (GT)(12) or (CT)(12) probes. Approximately 1.5% of the recombinants contained sequences that hybridized to either (GT)(12) or (CT)(12) dinucleotide probes, suggesting that microsatellites are abundant in the genome of An. maculatus. Estimation of abundance of the two dinucleotide repeats revealed that (GT)(n) or (CA)(n) microsatellites occur on average every 68 kb and (CT)(n) or (GA)(n) repeats every 495 kb. Among 23 microsatellite loci sequenced, four loci were selected to synthesize primers to perform polymerase chain reaction scoring for genetic polymorphism in a population of An. maculatus. A high level of polymorphism was observed with all four microsatellite loci analyzed. The number of alleles detected at each locus ranged from eight to 12 and the heterozygosities ranged from 0.25 to 0.54. A total of 42 alleles were found among four microsatellite loci. The large number of alleles and polymorphic nature resolved from microsatellite loci make these markers valuable for the study of population genetic structure and gene flow. Knowledge of gene flow is required to develop vector control strategies using genetic manipulations of malaria vector populations.