FIGURE 3.

Morpholino-targeted inhibition of the endogenous UTE modifies the 3′-end processing of the α-TM pre-mRNA. A, partial sequence of the α-TM pre-mRNA upstream of exon 9A9′. Exon sequences are indicated in capital letters, and intron sequences are in lowercase letters. The distal −274 branch point is shown in boldface characters, and the high affinity PTB binding sites are framed. UTE is delimited by brackets, and the targeting positions of UTE-1 and UTE-2 Mo are underlined. B, uninjected embryos or embryos injected with control Mo (Co Mo) or UTE-1 Mo or UTE-2 Mo were analyzed by a RNase protection assay using the probe illustrated at the top. Sequences derived from vector are represented by black rectangles. EF1-α and MLC1/3 probes were included in the assay as control for RNA recovery and embryo staging, respectively. The identity or composition of each protected product is indicated on the right. α7 RNA produced two protected fragments because of three nucleotide differences within exon 9A9′ between the two α-tropomyosin genes.