P{EP} insertion 330bp upstream of the rost translation initiation codon. The P{EP} element is oriented such that expression from the element results in overexpression of rost.
segment border muscle cell | ectopic, with Scer\GAL4how-24B
Duplication of the segmental border muscle is seen in about 25% of segments in embryos expressing rostEP2569 under the control of Scer\GAL4how-24B.