Fig. 6. vnd regulates expression of ind and msh in the pNE and brain NBs. Head flat preparations double stained with antibodies against Msh and En (A-L), or subjected to in situ hybridization against ind (M-X) of wild-type (wt; A-D,M-P), vnd mutant (vnd-; E-H,Q-T) and sca-vnd embryos (I-L,U-X); ventral views; stages as indicated. (B,D,F,H,J,L,N,P,R,T,V,X) Higher magnifications of the regions framed in A,C,E,G,I,K,M,O,Q,S,U,W, focusing on NBs and neuroectoderm (NE), respectively. (A,C) In wild type, Msh is found in the dorsal NE of the intercalary (IC), antennal (AN) and gnathal segments (MD, mandibular, MX, maxillary, LA, labial). (B,D) Dorsal NBs in the DC (B), and later in the TC/DC (D), express Msh. The ventral border of the Msh domain is indicated by a green broken line. It runs between the En-positive Dd5 and Dv8 (which does not express Msh). (E,G) In vnd-, Msh is expanded into the ventral pNE of the IC and DC. Ectopic Msh is not found in the PC. (F,H) Residual ventral NBs (white asterisks) in the TC and DC express ectopic Msh. Broken green line indicates the ventral border of the wild-type Msh domain (compare with B,D); the broken white line indicates ectopic Msh expression. (H) Ectopic Msh is found at lower levels in the en intercalary stripe (is; encircled with broken yellow line) owing to repression by ind, which is partly co-expressed (encircled with a broken yellow line in T). (I,K) In sca-vnd, Msh is largely repressed in the dorsal pNE. Low levels of Msh can be found in dorsalmost ectodermal patches in the head and trunk, and (J) sometimes in a dorsal NB in the DC (black asterisk). (L) Msh is almost completely repressed in NBs. (M,O) ind is expressed in three spots in the pNE of the intercalary (ind is, white arrowhead), antennal (ind as, red arrowhead) and ocular (ind oc, black arrowhead) segments. (N) The ind as gives rise to Dd1. (P) The ind is gives rise to Td1, Td2 and Td3. (Q,R) In vnd mutants, ind is and ind as are absent. ind is derepressed in ventral NE of the MD, MX and LA. (S,T) ind oc appears ventrally expanded; ind is becomes identifiable, but its overall size is reduced; ind as remains absent. (U,W) In sca-vnd, ind is largely repressed in the pNE. (V,X) Size of ind oc is diminished; ind is is absent, but ind as (and Dd1) is unaffected. (Y) Schemes summarizing the expression of ind and Msh in NBs of wild-type, vnd mutant and sca-vnd embryos at stage 11. Broken blue line encloses ventral NBs that, in wild type, persistently or transiently express Vnd until stage 11. Segmental borders are marked by broken red lines. as, en antennal stripe; hs, en head spot; is, en intercalary stripe; AN, IC, MD, MX, LA, antennal, intercalary, mandibular, maxillary, labial segment, respectively; CL, clypeolabrum; FG, foregut. Anterior is upwards.