Seven bilateral pairs of Ecol\lacZsvp-3-positive cells are visible in the embryonic dorsal vessel.
Expression of a svp-lacZ reporter occurs in an increasing number of procephalic neuroblasts through stages 9-11. At the end of neuroblast development in late stage 11 svp reporter expression is detected in 39 neuroblasts per hemisphere.
Reporter expression is observed in two pairs of cardial cells per segment. These correspond to the locations of the ostia.
Expression in procephalic neuroblasts stage 9-11: tritocerebrum - d6, d8, v2; deuterocerebrum - d1, d3, d6-8, d13, v2-8; protocerebrum - ad1, ad7, ad8, ad15, cd2, cd4, cd6, cd8, cd9, cd18, cd21, cv3, cv6, cv7, cv9, pd3, pd9, pd15, pd16, pd18, pd20, pv2
Ecol\lacZsvp-3 expression was usedas a cell marker for intermediate column neuroblasts 3-2, 5-3, and 7-2,but not 4-2 or 6-2. In wg mutant embryos, expression is seen inneuroblast 4-2 in addition to 3-2, 5-3, and 7-2. 6-2 never forms.
Enhancer trap expression is observed in a specified subset of neuroblasts in embryonic stages 8-11. (see also FBrf 51362)