Fig. 2. Transient transgenic analysis of zic2a-zic5 genomic
regions. (A) Conserved DNA regions (thick lines) at the
zic2a-zic5 locus. P2 and P5, each approximately 300 nt, are 70%
identical with Fugu. IG (840 nt) is 49% identical to Fugu,
and D5 (535 nt) is 60% identical to Fugu. Eight consensus
Tcf/Lef-binding sites were found in IG and six in D5 (asterisks). (B)
Transgenic constructs tested in transient assays. (C,D) Dorsal midbrain
and hindbrain expression of Gfp in representative zic5D5:gfp and
zic2aD5:gfp transient transgenics. Insets are dorsal views of the
embryos shown. Asterisks mark mid-hindbrain organizer. (E-G)
gfp RNA in representative transient transgenics. In embryos injected
with 25 pg of zic2aD5:gfp (E) or
zic2aD5
IG:gfp (F), expression was concentrated in
dorsal midbrain and hindbrain. Embryos injected with 25, 50 or 70pg of
zic2a:gfp (G) did not show enhanced expression. All views are
lateral, except for insets.