Fig. 2. The AP patterning system specifies the spatial pattern of cellularization. (A) An embryo from a bcd nos tsl/+ female. (B,C) Embryos from bcd nos tsl homozygous females. (A-C) First column: cross section through embryo showing stage of cellularization. Second column: focal plane through nuclei showing slightly anterior shift of Eve stripes (A), ubiquitous Eve (B), and minus the green channel (C) for better resolution of nuclei. Third column: focal plane through furrow canals showing uniform stalk diameters in (B,C). Red, Myosin; Green, Eve; Blue, DNA (Hoechst). The arrow marks the position of the first stripe of Eve in embryos in which the green channel has been removed so that yolk stalks may be seen more easily. Embryos from D,E are derived from females carrying six copies of bicoid. (D-E) First column: cross section through embryo showing stage of cellularization. Second and third columns: two different focal planes of furrow canals. Red, Myosin; Green, DNA; Blue, Eve. The embryos in the third column of D,E have had the blue channel removed so the yolk stalks can be clearly seen. The thin strips in the third row are higher magnifications of yolk stalks from the anterior domain (ad), pre-CF domain (pcf) and posterior domain (pd). (F,G) Cross sections through embryos showing stage of cellularization and depth of cellularization front. (F) Embryo from bcd nos tsl/+ female; (G) a bcd nos tsl homozygous female. Note deeper extent of cellularization front in the anterior in G than in the anterior in F.
