Influence of Temperature on Crossing-over in Drosophila

Abstract

ALTHOUGH it has now been demonstrated by several workers that crossing-over in certain regions of the chromosomes of Drosophila melanogaster is affected by temperature, the experiment reported in Table 8 of Plough's classical paper¹ still remains the only attempt to trace the magnitude of the effect through out the range of temperature over which Drosophila is fertile. Unfortunately, when correcting the data for differences among the controls, a mistake was made which led to the false conclusion that crossing-over showed two maxima, at 13° and at 31° C. The b–pr–c region of chromosome II was used for the experiment. The observed percentages of crossing-over between b and pr are reproduced in the table below: When corrections for the controls are properly applied the relation between crossing-over and temperature is seen to conform to a simple U curve (Fig. 1).