XB-IMG-131824
Xenbase Image ID: 131824
|
Fig. 4. Inducible forms of X-Su(H)1/Ank and ICD. hGR/ICD22 or
hGR/X-Su(H)1/Ank RNA (1.0 ng/embryo) were injected along
with Noggin RNA (0.3 ng/embryo) into two-cell stage embryos and
the induction of ESR-1 expression was measured in animal cap
assays as described in Fig. 3. (A) Neuralized animal caps
expressing the indicated constructs were either left untreated (-) or
exposed (+) to dexamethasone (DEX) for 3 hours. Note that ESR-1
expression increases following dexamethasone induction. Both
forms also induced ESR-1 expression in the absence of
dexamethasone, probably as a result of expressing them at levels
high enough to overwhelm mechanisms for cytoplasmic retention.
(B) Neuralized animal caps expressing the indicated constructs
were either left untreated (0) or exposed to dexamethasone for three
(3), two (2), or one (1) hour before harvesting. As a control,
neuralized animal caps were treated for 3 hours with
dexamethasone (Noggin+DEX). (C) Animal caps from embryos
injected with hGR/ICD22 RNA were (+) or were not (-) neuralized
(Noggin) and had (+) or had not (-) been treated with either
cycloheximide (CHX) and/or dexamethasone (DEX), as indicated.
This experiment was carried out both in the presence and absence
of Noggin, because we knew that ESR-1 expression can be induced
to higher levels in neuralized versus nonneuralized animal caps,
and we were concerned that the ability of noggin to neuralize
animal caps would be blocked by cycloheximide. Consistent with
this notion, the induction of ESR-1 in neuralized animal caps
appeared to be affected to a small degree by the addition of
cycloheximide (lane 9 versus 7), while no such effect was observed
in nonneuralized caps (lane 5 versus 3). ESR-1 RNA expression
levels in lanes 2-9 after normalizing to EF-1a are: 59, 174, 24, 96,
73, 180, 89, and 300. Image published in: Wettstein DA et al. (1997) Copyright © 1997. Image reproduced with permission of the publisher and the copyright holder. This is an Open Access article distributed under the terms of the Creative Commons Attribution License. Larger Image Printer Friendly View |