Figure 10. EGL-43 expression and
egl-43 mutant phenotypes. (A) Diagram of the EGL-43 protein and
egl-43 gene. WRM0622cG11 is a fosmid that rescues the
egl-43(
zu471) mutant; the site of gfp insertion for the EGL-43::GFP fosmid reporter is indicated. (B) Wild-type,
egl-43(
zu471) and ceh- 51
(tm2123) larvae immunostained for the basement membrane component UNC-52/Perlecan (red). The wild-type, but not mutant, basement membrane curves deeply inward, following the posterior surface of the
pm8 cell body and nearly separating the pharynx from the valve (see [22]). (C) Wild-type and
egl-43 larvae expressing reporters as listed for either
pm8 (
ref-1153 bp::GFP::CAAX),
v1 (
egl-43::GFP::CAAX), or
v2-
v3 (
mig-13::MIG- 13::GFP). Images are surface renderings as for Video S3, rotated to show posterior views of each cell(s); the midline is indicated by a blue arrow. Note the lack of
v2-
v3 cells dorsal to the midline in the
egl-43 mutant. (D) Images of hatched larvae expressing
mig-13::MIG-13::GFP (green) and showing the apparent absence of the
v3D valve cell in the
egl-43 mutant; the midline is indicated by an open arrowhead. (E,F) Live embryos showing EGL-43- dependent expression of
ref-11.8 kb::REF-1::GFP in
pm8. Notch-independent expression occurs in other pharyngeal cells, such as the sister cells
e2V and
mc3V (double-headed arrows); see [36]. (G,H) Live embryos showing the
egl-43(+) dependence of a
lin-12-derived reporter for the
pm8 family (green nuclei, lin-12pm8::HIS-GFP). The embryos are progeny of an
egl-43(
zu471)/mIn1[
dpy-10(
e128) mIs14] adult; the mIn1 balancer contains
egl-43(+) and a transgene that drives GFP expression in intestinal cells. Thus, only the embryo in G is
egl-43(+), and only this embryo expresses the
lin-12- derived reporter (see Table 1 for quantification). (I,J) EGL-43 expression in a wild-type embryo (I) and a
pha-4(
q490) mutant embryo (J, n = 14/14 embryos with similar expression). (K,L) EGL-43::GFP is not expressed in the pharyngeal precursors (blue outline) of most
tbx-35 (K) and
ceh-51 (L) mutant embryos. In these experiments, the EGL-43::GFP transgene was marked with
end-1::mCherry (not shown), and only mCherry-positive embryos were scored. (M) Partial lineage tree showing the MS descendants that express EGL-43::GFP, and showing the fates of these descendants in normal development (see [9]). Bars: (B-D) 5 microns; (E-L) 10 microns.