Body colour: flies carrying yTD2-4 (in a y- background) have a pigmentation score of 1 (where 1 = absence of y expression and 5 = wild type) in both the body and wing. Body colour: yTD2-4/y1#8 flies have a pigmentation score of 3 in the wing and 2-3 in the body. Body colour: yTD2-4/y59b flies have a pigmentation score of 3 in the wing and 2-3 in the body.