A new method to distinguish between meiotic and premeiotic recombinational events in Drosophila melanogaster.

A new method is proposed to distinguish between meiotic and premeiotic exchange events in Drosophila melanogaster males associated with male recombination activities. The method was applied to data that have accumulated in this laboratory during the past five years, and it was concluded that a large fraction, perhaps the overwhelming majority, of the male recombinants were due to exchange events that took place before meiosis.