Vicente-Steijn, RebeccaScherptong, Roderick W. C.Kruithof, Boudewijn P. T.Duim, Sjoerd N.Goumans, Marie Jose T. H.Wisse, Lambertus J.Zhou, BinPu, WilliamPoelmann, Robert E.Schalij, Martin J.Tallquist, Michelle D.Gittenberger-de Groot, Adriana C.Jongbloed, Monique RM2015-10-012015Vicente-Steijn, R., R. W. C. Scherptong, B. P. T. Kruithof, S. N. Duim, M. J. T. H. Goumans, L. J. Wisse, B. Zhou, et al. 2015. “Regional differences in WT-1 and Tcf21 expression during ventricular development: implications for myocardial compaction.” PLoS ONE 10 (9): e0136025. doi:10.1371/journal.pone.0136025. http://dx.doi.org/10.1371/journal.pone.0136025.1932-6203http://nrs.harvard.edu/urn-3:HUL.InstRepos:22856983Background: Morphological and functional differences of the right and left ventricle are apparent in the adult human heart. A differential contribution of cardiac fibroblasts and smooth muscle cells (populations of epicardium-derived cells) to each ventricle may account for part of the morphological-functional disparity. Here we studied the relation between epicardial derivatives and the development of compact ventricular myocardium. Results: Wildtype and Wt1CreERT2/+ reporter mice were used to study WT-1 expressing cells, and Tcf21lacZ/+ reporter mice and PDGFRα-/-;Tcf21LacZ/+ mice to study the formation of the cardiac fibroblast population. After covering the heart, intramyocardial WT-1+ cells were first observed at the inner curvature, the right ventricular postero-lateral wall and left ventricular apical wall. Later, WT-1+ cells were present in the walls of both ventricles, but significantly more pronounced in the left ventricle. Tcf21-LacZ + cells followed the same distribution pattern as WT-1+ cells but at later stages, indicating a timing difference between these cell populations. Within the right ventricle, WT-1+ and Tcf21-lacZ+ cell distribution was more pronounced in the posterior inlet part. A gradual increase in myocardial wall thickness was observed early in the left ventricle and at later stages in the right ventricle. PDGFRα-/-;Tcf21LacZ/+ mice showed deficient epicardium, diminished number of Tcf21-LacZ + cells and reduced ventricular compaction. Conclusions: During normal heart development, spatio-temporal differences in contribution of WT-1 and Tcf21-LacZ + cells to right versus left ventricular myocardium occur parallel to myocardial thickening. These findings may relate to lateralized differences in ventricular (patho)morphology in humans.en-USJournal Article2015-10-0110.1371/journal.pone.0136025