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Fig. 6. Loss of ADMP2 and heart formation. (A and B) Injection of 10 ng of an antisense ADMP2 morpholino oligonucleotide into each of the two anterior blastomeres of a 4-cell stage embryo inhibited the expression of the heart marker Nkx2.5 (c-MO: control morpholino; A-MO: antisense ADMP2 morpholino). (C) This effect was reversed by co-injection of 5 pg of ADMP2 δ-5′ UTR RNA (total 10 pg) (black arrowheads). (D) Transverse sections of c-MO-injected embryos showed that Nkx2.5 was expressed in a tube of myocardium (white arrowheads) as well as the pericardial roof (black arrowheads in panel D). (E) A-MO-injected embryos, on the other hand, showed only faint expression of Nkx2.5 (white arrowhead in panel E), and the heart tube was not formed. (F) Rescue of the A-MO phenotype, as in panel C. (G, H) Anterior injection of 10 ng A-MO also reduced the expression of TnIC, another heart marker (black arrowhead in panel K compared to that in panel J) (82%; Table 1). |
