Fig. 1. Isolation of a cis-regulatory module driving early animal
expression. (A) Ci-fog expression at the 16-cell stage.
Anterior is to the top for animal (an) and vegetal (veg) views, to the left
for the lateral (lat) view. (B) lacZ reporter activity (X-Gal)
at the 110-cell stage following electroporation of the
pfog-2000::NLS-lacZ construct. Lateral view, as in A. (C)
Timing of lacZ reporter activation in animal blastomeres after
electroporation of the pfog-2000 construct. Animal views of representative
embryos. (D) Phylogenetic footprinting between C. intestinalis
and C. savignyi sequences covering 2 kb upstream of the ATG of
Ci-fog. The conserved region is shown in pink, the heterologous
Ci-bra basal promoter in green. The level of lacZ reporter
activity is indicated for each electroporated construct (n
80),
from very strong (++++) to absent (-); with more than half of embryos counted
having all animal cells stained (++++), 50-90% of animal cells stained (+++),
25-50% (++) or 1-25% (+) of animal cells stained.