Expression of Wnt5, Wnt8 and Wnt16 in Achaearanea. At-Wnt5 is expressed segmentally in the developing neuroectoderm directly anterior to en (a), (b). At-Wnt5 expression can also be detected in the head lobes, the developing labrum, the developing heart, a ring like domain in the appendages and in the SAZ (a). At-Wnt8 is expressed segmentally and directly anterior to en expression (c), (d). At-Wnt8 is also expressed in the SAZ, the cephalic lobes, the developing stomodeum and the appendages. At-Wnt16 transcripts are also found in segmental strips directly anterior to en (e), (f), as well as in the tips of the legs and in a broad domain in the developing brain. At-Wnt16 expression is not observed in the SAZ (e). L1 and L4, leg bearing segments; O1 to O4, opisthosomal segments; SAZ, segment addition zone. All embryos are flat mounted with anterior to the left.