Fig. S8

isl1 morpholinos reduce Isl1 protein and phenocopy the isl1 mutant in the developmental timing assay. (A,B) Live images of a representative control embryo and an embryo that was injected with the isl1 MO. isl1 morphants present with cardiac edema and loss of motility. (C-K) Single z-scans of confocal images of 23-somite stage Tg(cmlc2:eGFP) embryos after immunofluorescence staining with α-eGFP (C,F,I) and α-Isl (D,G,J) antibodies. (C-E) Control injected embryo; (F-H,I-K) examples of isl1 morphants. Arrowheads in the overlay of α-eGFP (green) with α-Isl (red) indicate the eGFP^posIsl^pos cells in the cardiac disk. In the control (C-E), Isl is expressed in cardiac cells located at lateral positions in the cardiac disk (white arrowhead) and in the trigeminal sensory ganglion (green arrowhead), described in Fig. 3A-C. Note that the nuclear Isl signal in the cardiac disk in F-H and I-K is absent; however, some signal is still present in the trigeminal sensory ganglion in F-H. Scale bars: 80 μm. (L,M) The number of eGFP^posDsRed^pos (L) and eGFP^posDsRed^neg (M) cardiomyocytes/embryo. (M) The eGFP^posDsRed^neg cardiomyocytes are subdivided into those present at the arterial pole and those present at the venous pole. Note the significant reduction of eGFP^posDsRed^neg cells at the venous pole in the isl1 morphant embryos. Bars represent mean±s.e.m. *P<0.05; **P<0.01.