Project description:Through high-resolution single cell and genetic lineage/clonal analyses, we show an unsuspected clonal relationship between extraembryonic mesoderm and cardiac lineages. Single-cell transcriptomics and trajectory analyses uncovered two mesodermal progenitor sources contributing to left ventricle cardiomyocytes, one embryonic and the other with an extraembryonic gene expression signature. Additional lineage-tracing studies revealed that the extraembryonic-related progenitors reside at the embryonic-extraembryonic interface in gastrulating embryos, and produce distinct cell types forming the pericardium, septum transversum, epicardium, dorsolateral regions of the left ventricle and atrioventricular canal myocardium, and extraembryonic mesoderm. Clonal analyses demonstrated that these progenitors are multipotent, giving rise to not only cardiomyocytes and serosal mesothelial cell types but also, remarkably, extraembryonic mesoderm.
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:We use a human whole genome microarray to analyze the effects of nanosecond pulsed electric fields on Jurkat cells with the focus on early response genes to DNA damage. Keywords: nanosecond pulsed electric fields, jurkat cells, DNA damage
Project description:Cardiac development arises from two sources of mesoderm progenitors, the first (FHF) and the second heart field (SHF). Mesp1 has been proposed to mark the most primitive multipotent cardiac progenitors common for both heart fields. Here, using clonal analysis of the earliest prospective cardiovascular progenitors in a temporally controlled manner during the early gastrulation, we found that Mesp1 progenitors consist of two temporally distinct pools of progenitors restricted to either the FHF or the SHF. FHF progenitors were unipotent, while SHF progenitors, were either uni- or bipotent. Microarray and single cell RT-PCR analysis of Mesp1 progenitors revealed the existence of molecularly distinct populations of Mesp1 progenitors, consistent with their lineage and regional contribution. Altogether, these results provide evidence that heart development arises from distinct populations of unipotent and bipotent cardiac progenitors that independently express Mesp1 at different time points during their specification, revealing that the regional segregation and lineage restriction of cardiac progenitors occurs very early during gastrulation. We used microarrays to characterize the molecular mechanisms that control Mesp1 progenitor specification and lineage segregation during the early stage of cardiac mesoderm formation, 50 Mesp1 H2B-GFP+ or Mesp1 H2B-GFP- cells at E6.5 or E7.5 from mouse embryos were sorted for RNA extraction, amplification and hybridization on Affimetrix microarrays. Microaarrays were performed on Mouse Genome 430 PM strip Affymetrix array. The overall design was repeated in two different biological samples.
Project description:Cardiac development arises from two sources of mesoderm progenitors, the first (FHF) and the second heart field (SHF). Mesp1 has been proposed to mark the most primitive multipotent cardiac progenitors common for both heart fields. Here, using clonal analysis of the earliest prospective cardiovascular progenitors in a temporally controlled manner during the early gastrulation, we found that Mesp1 progenitors consist of two temporally distinct pools of progenitors restricted to either the FHF or the SHF. FHF progenitors were unipotent, while SHF progenitors, were either uni- or bipotent. Microarray and single cell RT-PCR analysis of Mesp1 progenitors revealed the existence of molecularly distinct populations of Mesp1 progenitors, consistent with their lineage and regional contribution. Altogether, these results provide evidence that heart development arises from distinct populations of unipotent and bipotent cardiac progenitors that independently express Mesp1 at different time points during their specification, revealing that the regional segregation and lineage restriction of cardiac progenitors occurs very early during gastrulation. We used microarrays to characterize the molecular mechanisms that control Mesp1 progenitor specification and lineage segregation during the early stage of cardiac mesoderm formation,