GFP expression is driven by the bab1 dimorphic element in the "light 1" strain of Drosophila melanogaster and a 119bp sequence from the bab2 promoter.
bab1Light1 complements Df(3L)babAr07 with regard to abdomen tergite pigmentation. bab1Dark1 also complements the posterior abdomen phenotypes and development of the leg tarsal segments.