DEVELOPMENT OF A POLYMERASE CHAIN-REACTION ASSAY FOR DIFFERENTIATION BETWEEN CULEX-PIPIENS PIPIENS AND CX-P-QUINQUEFASCIATUS (DIPTERA, CULICIDAE) IN NORTH-AMERICA BASED ON GENOMIC DIFFERENCES IDENTIFIED BY SUBTRACTIVE HYBRIDIZATION

Culex pipiens is a complex of mosquitoes that are involved in the tran smission of pathogens, including St. Louis encephalitis virus in North America, The 2 major taxa in the complex, Cx. p. pipiens and Cx. p. q uinquefasciatus, are nearly identical morphologically, making identifi cation of field-collected specimens difficult, and attempts at differe ntiation based on biochemical and molecular techniques have been unsuc cessful. We report here tile use of genomic subtractive hybridization to identify a region of nucleic acid heterology between the genomes of Cx. p. pipiens and Cx. p. quinquefasciatus and the development of a p olymerase chain reaction (PCR) assay to discriminate between them. PCR primers based on tile nucleic add sequence of a Cx. p. piplens-unique DNA fragment were used to differentiate Cx. p. pipiens and Cx. p. pip iens/quinquefasciatus hybrids from Cx. p. quinquefasciatus by using ex tracted individual mosquito genomic DNA, crude DNA preparations from a mosquito head or legs, and DNA from triturated mosquito pools.