Mitochondrial DNA variation among Anopheles albimanus populations

Barriers to gene flow between Pacific and Atlantic coast populations of Ano pheles albimanus were reported in an earlier study of variation in the inte rgenic spacer of the nuclear ribosomal DNA. We examined the distribution of mitochondrial DNA haplotypes among A. albimanus populations to test for ge ne flow barriers with an independent genetic marker. A region of the NADH d ehydrogenase subunit 5 gene was amplified by the polymerase chain reaction (PCR) in 1,105 mosquitoes collected from 16 locations in Guatemala and in s ingle collections from Mexico, Honduras, Nicaragua, Costa Rica, Panama, Col ombia, and Venezuela. The PCR products were tested for variation using sing le strand conformation polymorphism analysis and 45 haplotypes were detecte d. Haplotype frequencies did not vary between coasts in Guatemala. Populati ons within similar to 200 km of one another were panmictic. However, at dis tances > 200 km, F-ST and geographic distances were correlated suggesting t hat populations are isolated by distance.