GEOGRAPHIC-VARIATION OF ADH, ALPHA-GPDH, AND EST-6 IN EURASIAN NATURAL-POPULATIONS OF DROSOPHILA-MELANOGASTER

The allele frequencies of three allozyme loci, ADH, alpha-GPDH, and ES T-6, were assessed in 18 natural populations of Drosophila melanogaste r of Eastern Europe, the Caucasus, and Central Asia. The obtained data were combined with the data of other authors on ADH, alpha-GPDH, and EST-6 polymorphism in other regions of Eurasia and analyzed to find th e pattern of geographic differentiation on a continental scale. The AD H-S allele frequency was shown to be negatively correlated with latitu de and the average rainfall of the driest calendar month and positivel y correlated with the average temperature of the coldest calendar mont h and the average rainfall of the wettest calendar month. The frequenc y of alpha-GPDH-S increased in the western part of Eurasia and was not associated with climatic variables. The frequency of EST-6-S decrease d toward the center of the continent and was positively correlated wit h the temperature of the coldest month and with the rainfall of the dr iest month. The results are discussed in relation to the laboratory da ta on selective differences between the allozymes.