Fig. 4

Relative expression domains of different genes in the posterior of the embryo, as illustrated by combinations of double staining. a cad and eve are co-expressed in the posterior GZ, with eve stripes extending into the anterior GZ. b eve and odd, are shifted relative to each other, with overlapping expression in a narrow area (posterior of eve and anterior of odd), but with most of the expression separate. c The relationship between eve and sob is identical to that between eve and odd. d opa and slp are expressed in adjacent domains with no observable overlap. The posterior stripes are complementary and cover the entire anterior GZ. In later, more anterior stripes, as the segment grows, a region without opa or slp emerges, anterior to opa and posterior to slp. In later stages, opa and slp are completely separated. e slp expression begins just as eve expression is fading. In the segments where they are both expressed, slp is expressed to the anterior of eve. f The transition between eve and inv defines the GZ-germband border. At the transition, they are co-expressed in one or two stripes, in which their domains overlap. g The first stripes of hh expression overlap those of eve in the anterior GZ. h hh is immediately adjacent and posterior to wg in segmental stripes beginning in the anterior GZ. This relation is maintained in the posterior GZ, where both are expressed in non-overlapping patches. i Dl and eve are partially co-expressed in the anterior GZ, with Dl extending more anteriorly than eve, and eve beginning posteriorly to their overlapping domain. j h is expressed immediately posteriorly to inv, beginning slightly more anteriorly. Anterior is to the left in all images