The New World Screwworm (NWS), Cochliomyia hominivorax, is one of the most important parasitic insect pests causing invasive myiasis in livestock. To investigate specific evolutionary patterns of evolution, enhance the efficiency of the implementation of the eradication program and reduce risk associated with the introduction into new areas it is necessary to determine the genetic variability and population structure of the NWS across its current geographic distribution. In order to obtain microsatellite markers, genomic DNA extracted from colony-bred pupae was digested with Sau3AI and fragments of 200-800bp were recovered and linked to oligonucleotide adapters. Fragments containing AC repeats were selected by hybridization to biotinilated oligonucleotides bound to magnetic beads. This fraction was used to construct a small insert genomic library enriched for the motif poli-AC and the microsatellite-containing clones were confirmed by plaque hibridizations. An anchor-PCR assay was performed to verify the size and orientation of the fragments containing AC repeats. A total of 40 ancored-PCR-selected clones were sequenced, resulting in 19 useful sequences for designing primers. Specific primers complementary to flanking regions of the microsatellite loci were designed and synthesized. The selected loci are being currently analized to evaluate their utility in population genetic studies of NWS. The isolation and characterization of microsatellite markers open a new perspective for the generation of fundamental population genetic data of NWS from South America populations and for monitoring the expansions of the pest into screwworm-free areas. Financial support: FAPESP, CNPq and IAEA.
Species 1: Diptera Calliphoridae Cochliomyia hominivorax (New World Screwworm)
Keywords: Microsatellite
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