D The age of Bcd and its gradient are unaltered in fsd mutant. Comparison of a representative y/w embryo (left) and loss-of-function mutation fsdKG02393 (right) are shown. Both embryos have the tFT-Bcd construct in the same locus, are in early n.c. 14, were imaged side-by-side under identical conditions, and are displayed with the same settings. Embryo "shells" are displayed. 