The frequency of allelic lethals and complementation maps in natural populations of drosophila melanogaster from Mexico

Abstract

Departing from a previous study on the genetic loads affecting the second chromosome of Drosophila melanogaster in four natural populations, 171 lethal chromosomes were recovered and maintained as a balanced stocks in the condition Cy L / 1 (l=lethal); of those lethais 24 correspond to population A, 50 to populations B and C and 47 to population D. later on an intra-population allelism test for the four populations was performed for each one. A total of 3807 inter lethal crosses were done yielding a total of i 10 allelic combinations, from them the respective percentage of allelism for each population was calculated and they are as follow: 3.98 % for population A, 1.80 % for population B, 3.67 % for population C and 2.96 % for population D. the observed values for the frequency of allelism in these populations are not significantly different from those reported by other authors in similar studies in natural and/or experimental populations. Beside these values the frequency for singles, doubles, triplets and even quadruplets present in each population were determined, they shown the presence of various complementation maps due to the clustering of few different lethals: also a large complementation map formed by a large cluster involving the presence of 26 different lethals found in population D all of them combined constituting a single unit was found.