ANALYSIS OF PATTERN IN DISTRIBUTION OF BREAKAGE POINTS IN THE CHROMOSOMES OF ZEA MAYS L. AND D. MELANOGASTER MEIGEN

Abstract

Analyses of the populations of breakage points from the chromosome arms of Zea mays L. and Drosophila melanogaster Meigen demonstrate significant deviations from equidistributions. In both organisms, greater than expected frequencies of breakage points were found in regions near the centromere and, in the case of maize, in the centromere. After correction for the distribution of breakage points, departures from an equidistribution of pair reassociation were described in maize. Reassociation frequencies found in maize chromosome arms VL, VIIIS, VIIIL, IXL and XS were mainly responsible for the large deviations from expected values.