Project description:The purpose of this study was to identify the source of Wnt signals that lead to development/proliferation of the heart fields, particularly the second heart field. To this end, we knocked out Wntless (Wls), which is necessary for Wnt secretion, in Mesp1+ lineage cells. We performed single cell RNA-seq to better identify the source of Wnt signals and the effects of the loss of Wnt secretion in mesoderm.
Project description:Analysis of whole heart samples from Hdac3-Isl1KO embryos at embryonic day E9.5. Results provide insights into the role of Hdac3 in second heart field-derived cardiac cells. We used microarray to investigate the gene expression program affected by Hdac3 during cardiac development and identified patterns of differentially-expressed genes and pathways during this process.
Project description:The discovery of the first heart field (FHF) and the second heart field (SHF) led us to understand how cardiac lineages and structures arise during development. However, it remains unknown how they are specified. Here, we generate precardiac spheroids with pluripotent stem cells (PSCs) harboring GFP/RFP reporters under the control of FHF/SHF markers, respectively. GFP+ cells and RFP+ cells appear from two distinct areas and develop in a complementary fashion. Transcriptome analysis shows a high degree of similarities with embryonic FHF/SHF cells. Bmp and Wnt are among the most differentially regulated pathways, and gain- and loss-of-function studies reveal that Bmp specifies GFP+ cells and RFP+ cells via the Bmp/Smad pathway and Wnt signaling, respectively. FHF/SHF cells can be isolated without reporters by the surface protein Cxcr4. This study provides novel insights into understanding the specification of two cardiac origins, which can be leveraged for PSC-based modeling of heart field/chamber-specific disease.