Does RNA interference influence meiotic crossing over in Drosophila melanogaster?

Mutations in the RNA interference (RNAi) genes aubergine (aub), homeless and piwi were tested for effects on the frequency, distribution and coincidence of meiotic crossovers in the long arm of the X chromosome. Some increases in crossover frequency were seen in these tests, but they may have been due to a maternal effect of the balancer chromosomes that were used to maintain the RNAi mutations in stocks rather than to the RNAi mutations themselves. These same balancers produced strong zygotic interchromosomal effects when tested separately. Mutations in aub and piwi did not affect the frequency of crossing over in the centric heterochromatin of chromosome II; nor did a balancer chromosome III.