Comparison of chromosome and isoenzyme polymorphism in geographical populations of Leishmania (Viannia) peruviana

Five chromosomes and 17 isoenzyme loci were analysed in 4 allopatric popula tions of Leishmania (Viannia) peruviana, and molecular distances calculated with 2 estimators, Chromosomal Size Difference Index and Jaccard Distance. Chromosome and isoenzyme data were in overall concordance: 13/30 isolates clustered similarly on the dendrograms constructed from the different estim ators, and a significant correlation (P < 0.001) was observed between the m olecular distances calculated from the two sets of characters. This indicat es an evolutionary association between chromosomal size polymorphism and is oenzymes. Chromosomes have a faster molecular clock than isoenzymes; twice as many genotypes were identified by chromosome analysis and significant si ze differences (for a total of up to 500 kb for 5 chromosomes together) wer e observed within a given zymodeme. Chromosomes most likely represent bette r indicators of genetic drift than isoenzymes, as suggested by the higher c orrelation between both estimators of chromosomal size-polymorphism and eco -geography. Some chromosomes might present an adaptive response to environm ental variation.