Spatiotemporal characterization of human early intervertebral disc formation at single-cell resolution

Intervertebral disc (IVD) performs as a fibrocartilaginous joint to anchor adjacent vertebrae (VB) and is essential for the mechanical stabilization of axial skeleton. Although several studies have demonstrated the cellular heterogeneity of adult mature IVD, a single-cell transcriptomic atlas mapping early IVD formation is still lacking. Here, we generated the first spatiotemporal and single-cell based transcriptomic atlas of human IVD formation at embryonic stage, as well as a comparative mouse transcript landscape. The notochord (NC)/nucleus pulposus (NP) cells, vertebral chondrocytes, and annulus fibrosus (AF) cells were characterized. Our single-cell transcriptomic atlas that resolves spatiotemporally regulated cellular heterogeneity underlying early IVD development will be leveraged to develop preventative and regenerative strategies for IVD degeneration. Three embryonic mouse axial skeleton at E11.5-13.5 were cryosectioned to a thickness of 10 m, followed by spatial transcriptome analysis via 10x Genomics Visium.