Human diseases are seldom confined to individual tissues or organs, but instead present with a spectrum of comorbidities. A common example includes a group of congenital diseases with linked heart, limb, and lung defects. Using zebrafish as model, the goal of my research is to uncover how individual causative genes drive multi-organ comorbidities in the heart, limb, and lung. Understanding the underlying mechanisms will contribute to the development of therapeutics across disease groups and improve predictive diagnostics of patients with complex multi-organ diseases. In the adult body, the heart, limb, and lung vasculature seem unrelated at the structural level, yet share a close developmental origin in the embryo. These structures all derive from uncommitted lateral plate mesoderm that harbors progenitor cells for numerous organ systems. My overarching hypothesis posits that the lineages of the heart, limb, and lung blood vessels (cardiopharyngeal vasculature) derive from a common progenitor population within the lateral plate mesoderm, and form in an interconnected manner through the action of TBX-FGF and lineage-specific signaling inputs. In Aim 1, I will test the lineage connection between heart, pectoral fin, and cardiopharyngeal vasculature using transgenic lineage labeling and CRISPR-Cas9-based barcoding experiments. My work will directly test my hypothesis that heart, limb, and lung defects are linked by a shared developmental origin of the affected cell types. In Aim 2, I will functionally test the contribution of TBX-FGF signaling pathways, and lineage-specific inputs on joint heart, limb, and cardiopharyngeal vasculature lineage patterning. These experiments will test the impact of shared and lineage-specific signaling perturbation on co-occurrence and severity of heart, pectoral fin, and cardiopharygneal vasculature defects. Upon completion of my aims I will have tested how shared lineage origins, and perturbation of shared signaling pathways and lineage-specific inputs, contribute to human diseases with linked heart, limb, and lung defects. Altogether, my proposed research aims, my technical training, and my career development plan will provide the basis for my career goal of becoming an independent investigator at a leading research institution. During the K99 phase, I will receive mentorship from my mentor Dr. Christian Mosimann and my advisory team, and technical training from my collaborative team consisting of light sheet microscopy, scRNA-seq experimental design, and cardiovascular phenotypic analysis. My career development plan will further my training in intellectual development and collaboration, scientific writing and communication, and mentorship and teaching, facilitating my transition to an independent investigator during the R00 phase. The section of Developmental Biology within the Department of Pediatrics at the CU Anschutz Medical Campus is an exceptionally supportive environment, providing extensive resources that...