The fushi tarazu gene is essential for the establishment of the Drosophila embryonic body plan.

When first expressed in early embryogenesis, fushi tarazu mRNA is uniformly distributed over most of the embryo.

Subsequently, fushi tarazu mRNA expression rapidly evolves into a pattern of seven stripes that encircle the embryo.

The instability of fushi tarazu mRNA may contribute to the localization of this pattern of expression, but this is unlikely to be a dominant effect since the 744 base-pair ftz zebra stripe element can drive the ectopic expression of a reporter construct (with mRNA structure entirely unrelated to the ftz transcript) in a qualitatively highly similar pattern.

The FIE3 lies within a 201-nucleotide sequence just upstream of the polyadenylation signal and can act autonomously to destabilize a heterologous mRNA.