Year: 2026
Type: preprint
Abstract: SUMMARY The mesoderm coordinates organogenesis and generates the cardiovascular, visceral and musculoskeletal systems, yet in mammals this germ layer is difficult to access, impeding its genetic manipulation and study. Here, we establish embryonic day (E) 7.5 exocoelomic cavity nano-injection as a scalable route for selective genetic targeting of mouse mesoderm. Combining in utero lentiviral barcoding with single-cell and spatial transcriptomics, we reconstructed mesodermal and neural crest clonal relationships across >590,000 cells and 31,000 multicellular clones from E9.5–E10.5 embryos and E16.5 livers and hearts. In liver, capsular mesothelium was closely related to hepatic stellate cells, whereas fibroblast and vascular smooth muscle lineages diverged earlier. In heart, epicardium was clonally coupled to three spatially restricted mesenchymal sub-lineages but not to cardiomyocytes, and lineage tracing separated epicardial- and neural crest-derived populations within transcriptionally convergent valve mesenchyme. This approach enables Cre-independent manipulation of mammalian mesoderm and resolves organ mesenchyme development at clonal resolution. HIGHLIGHTS - E7.5 exocoelomic nano-injection barcodes mouse mesoderm without Cre drivers. - Clonal maps span >590,000 cells and 31,000 multicellular clones in vivo. - Mesothelial subsets are lineage-biased sources of liver mesenchymal diversity. - Epicardium seeds three spatial mesenchymal lineages but not cardiomyocytes. - Clonal tracing resolves convergent neural crest and mesodermal valve mesenchyme.
Authors: Jingyan He, Johan Lorentz, Agustín A. Corbat, Sergey Isaev, Raphaël Mauron, Sandra De Haan, Lenka Belicová, Jia Sun, Bettina Semsch, Noémi Van Hul, Robert Tonoian, John Wilson, Ulrika Marklund, Marcel Martin, Neil C. Henderson, Jonas Frisén, Michael Ratz, Peter V. Kharchenko, Igor Adameyko, Enikő Lázár, Joakim Lundeberg, Emma R Andersson
Institutions: Howard Hughes Medical Institute, Janelia Research Campus, Karolinska Institutet, Universidad de Buenos Aires, Medical University of Vienna, Science for Life Laboratory, KTH Royal Institute of Technology, Leiden University Medical Center, Karolinska University Hospital, Centre for Inflammation Research, University of Edinburgh, Stockholm University, Institute of Genetics and Cancer, MRC Human Genetics Unit, Institute of Molecular Biotechnology
Language: English
Subfield: Molecular Biology
Domain: Life Sciences
Open Access status: green
Awards: Investigation of antifibrotic targets in human liver fibrosis using a single cell transcriptomics approach., Beyond NEPTUNE (Neural plate targeting with in utero nano-injection): Targeting new organ systems to Reduce the numbers of mice used in science., G1273951262, G1332648248, G1513205627, G1892925485, High-throughput rapid manipulation of gene expression in the mouse: an efficient method to dramatically reduce the numbers of mice used in basic science (Continuation), Unravelling the Notch code in hepatic portal vein mesenchyme: Master controller of portal triad development and architecture?, Investigation of antifibrotic targets in human liver fibrosis using a single cell transcriptomics approach., Reduction and refinement of mouse usage with in utero engineered mouse models, G8309358643
OpenAlex ID: W7214077428