Fig. 8. (A-D) Expression pattern of GmASH. Flat preparations of whole embryos stained for a DIG-labelled GmASH probe. Anterior is towards the top. (A) An anterior to posterior gradient of GmASH expression is visible in the neurogenic regions of the embryo. The mediolateral extension of the GmASH expression domain is smaller in the head segments. An identical GmASH expression pattern is visible in the leg segments 1 and 2 (arrow), while the former expression pattern of anterior segments can be detected in leg segment 3 (arrow; compare to Fig. 7F,G). (B) At stage 3, GmASH expression forms a semicircle around the central region of the hemisegments (arrow). The former expression pattern of the anterior segments is now visible in leg segment 3 (arrow). (C) GmASH expression has extended posteriorly to leg segment 5. The arrow points to the transient expression of GmASH in the invaginating cell groups. (D) After formation of all invagination sites, GmASH is still expressed in about half of them. In addition, the gene is expressed in the precursors of the peripheral nervous system (arrows). ant, antennal segment; l1 to l7, leg segments 1 to 7; md, mandibular segment; mx, maxillar segment; pmd, premandibular segment; pmx, premaxillar segment. Scale bar: 120 µm in A-D.