Use of a restriction fragment length polymorphism (RFLP) as a genetic marker in crosses of Anopheles gambiae (Diptera: Culicidae): independent assortment of a diphenol oxidase RFLP and an esterase locus.

Analysis of restriction fragment length polymorphism (RFLP) is a powerful tool for analyzing linkage relationships in species where few genetic markers have been described and where conduct of crosses is difficult. It also permits integration of genetic and physical (cytogenetic) data when the probes have been mapped by in situ hybridization. To illustrate the utility of the method, and because some mutations of a diphenol oxidase gene might conceivably produce the malaria refractoriness phenotype of ookinete-oocyst encapsulation, backcrosses between two inbred lines of Anopheles gambiae Giles were carried out to determine the linkage relationship between the diphenol oxidase A2 (Dox) gene and the esterase locus associated with refractoriness to Plasmodium cynomolgi NIH. The Dox alleles were a Sal I restriction fragment length polymorphism visualized by probing Southern blotted DNA from portions of individual mosquitoes with a cloned Dox gene probe. The two genes were shown to segregate independently.