Molecular differentiation of two new world saurian Plasmodium species in different host species using the polymerase chain reaction.

Several isolates of Plasmodium floridense obtained from naturally infected Anolis carolinensis and Anolis sagrei, and 2 isolates of Plasmodium chiricahuae obtained from Sceloporus jarrovi were characterized at the ribosomal DNA (rDNA) locus using the polymerase chain reaction and agarose gel electrophoresis. Enzymatic amplification of the rDNA locus from both Plasmodium species resulted in the generation of a 590-base pair (bp) DNA fragment. The results obtained with all isolates of P. floridense appeared as a doublet, with the second fragment being approximately 630 bp in size. Isolates of P. floridense obtained from A. carolinensis from ecologically different northern and southeastern Florida, and from A. sagrei a the same southeastern Florida site, were demonstrated to be molecularly similar. Plasmodium floridense and P. chiricahuae were molecularly distinct at the 18s rDNA locus, thus confirming their morphological and morphometrical distinction as taxonomic species. Anolis sagrei is a third natural host species for P. floridense in Florida.