Generating a precise cellular and molecular cartography of the human embryo is essential to our understanding of the mechanisms of organogenesis in normal and pathological conditions. Here, we have combined whole-mount immunostaining, 3DISCO clearing, and light-sheet imaging to start building a 3D cellular map of the human development during the first trimester of gestation. We provide high-resolution 3D images of the developing peripheral nervous, muscular, vascular, cardiopulmonary, and urogenital systems. We found that the adult-like pattern of skin innervation is established before the end of the first trimester, showing important intra- and inter-individual variations in nerve branches. We also present evidence for a differential vascularization of the male and female genital tracts concomitant with sex determination. This work paves the way for a cellular and molecular reference atlas of human cells, which will be of paramount importance to understanding human development in health and disease. PAPERCLIP.
161 - 173.e12
3DISCO, database, embryo, fetus, human, iDISCO, light sheet microscopy, nervous system, tissue clearing, urogenital system, Embryo, Mammalian, Embryonic Development, Fetus, Human Development, Humans, Imaging, Three-Dimensional, Immunohistochemistry, Microscopy, Organogenesis, Peripheral Nervous System