(Downloading may take up to 30 seconds.
If the slide opens in your browser, select File -> Save As to save it.)
Click on image to view larger version.

Fig. 4. Injection of morpholino antisense oligonucleotides (MOs) directed
against the translational initiation site of ß-catenin-2 can
phenocopy the ichabod mutation, whereas MOs against
ß-catenin-1 have no ventralizing effect. (A-C) Effect
of injection of MO1 into wild-type embryos. Injection of 1 mM MO1 often
results in a slight necrosis in the head (B) and 3 mM MO1 causes more severe
necrosis and bent shortened tails (C), but in neither case were the embryos
ventralized. A wild-type embryo at the same stage is shown for comparison (A).
(D-G) Effect of injection of MO2 into wild-type embryos. Examples of
Class 2 (E) and Class 1 (F) embryos obtained by injecting wild-type embryos
with 3 mM MO2 are compared with a wild-type embryo (D) and an embryo injected
with 3 mM MO2mis (G). (H) The effects of injection of 3 mM
MO2 can be rescued by co-injection of ß-catenin-2*
RNA (ß-catenin-2 RNA with an altered ribosome binding region
that will not bind to MO2). Injection of 3 mM MO2 alone yielded a distribution
of ventralized phenotypes (red bars). Injection of
ß-catenin-2* RNA alone had no ventralizing effect
(compare green and yellow bars). Co-injection of MO2 and the RNA yielded
mostly wild-type-appearing embryos, with only a few embryos exhibiting weak
ventralization (blue bars). In this experiment, we classified non-ventralized
embryos into two classes, wild-type and C5, with C5 embryos exhibiting kinky
notochords. (I) Injection of MO2 into ichabod embryos shifted
the phenotypic distribution to more-severe ventralized classes.