Two splice-site targeted Disc1 morpholinos altered disc1
transcript size and craniofacial development. (A) RT-PCR analysis
of MOE3-injected embryos demonstrated alternative splicing of disc1
pre-mRNA resulting in a smaller transcript. At 6 hpf, maternally expressed
disc1 could not be modified by the splice site-targeted morpholino,
which resulted in the wild-type transcript present. (B) MOE8 injection
also effectively altered transcript size. (C-H) Morpholino-mediated
Disc1 knockdown resulted in three classes of craniofacial cartilage defects.
(C,F) Class 1 (normal); (D,G) class 2; (E,H) class 3. (C-E) Lateral views;
(F-H) ventral views with anterior to the left. (I) The ratio of MOE3
and MOE8 morphant embryos in each class was dose dependent. (I, right)
Although half-effective doses of MOE3 or MOE8 did not affect craniofacial
development, they acted synergistically to produce a high ratio of larvae with
abnormal craniofacial cartilage.