Fig. 3. Phenocopies of hab allele-specific traits by disruption of EC1 or EC4. (A) Injection of morpholino oligonucleotide MO1 into wild-type embryos at increasing doses mimics the epiboly arrest phenotype. (B) Phenotype of hab^dtv43/dtv43 at equivalent stage. (C) Aberrant splice products caused by MO1 appear at doming, shortly after the beginning of zygotic transcription (Kane and Kimmel, 1993). Arrow indicates maternal product. (D) Splicing event caused by MO1 (black bar) and conceptual protein, inferred by sequencing RT-PCR product using the primers indicated by arrows in exon8 and exon11. (E) Injection of MO2 into wild-type embryos at increasing doses causes a severe epiboly arrest, uneven radial intercalation (arrow) and dissociation of the blastoderm (arrowhead). (F) Injection of MO2 into wild-type embryos at low doses mimics the ZMD trait. Embryos are shown at the 5-somite stage and the detached cell region is shown beneath at higher magnification. (G) Phenotype of ZMD hab^tm94/+. (H) Splice products caused by MO2. (I) Splicing event caused by MO2 and the conceptual protein, as inferred by sequencing the RT-PCR product using the primers indicated in exon4 and exon 12.