Fig. 4

erbb2 mutant HL phenotypes result from the absence of trabecular formation (A) Schematic of transplantation experiment resulting in transplanted blastomeres from Tg(myl7:mKateCAAX);Tg(myl7:Cypher-EGFP) erbb2 control or erbb2^−/− donors into Tg(myl7:rasGFP); Tg(myl7:Cypher-EGFP) wild-type hosts. (B-B”,E-E”) Mid-chamber confocal sections of control and erbb2^−/− donor CMs, respectively, in wild-type host ventricle. (B”’,E”’) Magnified high-resolution images of compact myocardial wall and trabecular regions marked by dotted box in B”, E”. Yellow arrows point to length of donor CM (yellow line) along compact myocardial wall. White arrow heads point to length of host CM (white line) along compact myocardial wall. White arrows point to trabeculae. (C,F) Maximal projection of confocal Z-stacks of ventricle. (D,G) Magnified high-resolution images of compact myocardium, revealing sarcomere structures of control and erbb2^−/− donor CMs, respectively, in wild-type host ventricle at 5 dpf. (H–J) Quantification of cross-sectional area of erbb2 control donor and erbb2^−/− donor CMs (H), erbb2 control donor and host CMs (I), and erbb2^−/− donor and host CMs at 5 dpf (J). (K) Quantification of Z-line length of erbb2 control donor and erbb2^−/− donor CMs at 5 dpf. (L) Quantification of distance between Z-lines of erbb2 control donor and erbb2^−/− donor CMs at 5 dpf. Data are represented as mean ± SEM.