EcollacZunpg-f85 is first detected in the embryonic CNS at embryonic stage 8, in neurectodermal and mesodermal cells at the ventral midline, with an anterior limit at the cephalic furrow. These expression domains widen, and have an eventual anterior-most border in the posterior deuterocerebrum. Expression is adjacent to, but is not in the same cells as, oc.
Enhancer trap expression is restricted to the lateral ectoderm of the prothoracic segment. A segmentally repeated pattern in the neuroblasts and neurons is also observed.
P{lacZ} is inserted in a 1360 element located in the first intron of unpg