Accuracy of bristle placement on a leg segment in Drosophila melanogaster

Bristle positions in two rows of bristles on the basitarsus of the second leg of the fruitfly Drosophila melanogaster were analyzed in order to determine the accuracy of bristle placement within these rows. Within each row the positions of the two terminal bristles were found to be approximately equally variable, and positional variability was found to increase toward the middle of each row. Rows having fewer bristles manifested more positional variability in their midsection. These results are interpreted in terms of a possible bristle spacing mechanism involving repulsive forces between mobile bristle cells.