Figure 1.—

Thoracic trident pigmentation pattern and its association with the third chromosome. (A) Thorax segment of Mel6 (G59) originated from Benin, West Africa. (B) Thorax segment of TW1 (G23) originated from Taiwan. Mel6 (G59) and TW1 (G23) were subjected to 23 and 59 generations of sib mating, respectively, to construct nearly isogenic lines. (C) Trident phenotypes of the whole-chromosome substitution lines between Mel6 and TW1. Chromosome origins and the trident phenotypes of the lines are indicated in the left and right columns, respectively. These lines were generated using balancer chromosomes by a similar scheme used in Hollocher et al. (1997). Pigmentation intensity was examined under the microscope.