Rappeneau, Q. | bioRxiv Science

bioRxiv2025

Role of Neural Crest Cells in Establishing Corneal Transparency During Embryonic Development in Mice

This study deciphers the exquisitely timed cellular and molecular symphony orchestrating corneal development in mice, revealing how neural crest cells (NCCs) transition from multipotent progenitors to architects of a light-transmitting, mechanically robust stroma. Between embryonic day 10 until birth, NCCs undergo posteroanterior differentiation marked by sequential downregulation of stemness markers, paralleled by collagen I deposition initiating at E12. Stromal expansion and keratocyte-driven ECM remodelling yield precisely aligned collagen fibrils within lamellae a configuration enabling transparency through destructive interference of scattered light. Keratocytes adopt a dendritic morphology to minimize light scatter, while secreting crystallin-like proteins that match refractive indices between cells and matrix. Corneal endothelial maturation and dynamic ECM stratification culminate in a tissue optimized for both optical clarity and structural resilience. Our study elucidates the complex choreography of cellular and molecular events underpinning corneal development, offering novel insights into the acquisition of the corneas unique optical and biomechanical properties.

cell biology↗

bioRxiv2019

An alternative mechanism of early nodal clustering and myelination onset in GABAergic neurons of the central nervous system

In vertebrates, fast saltatory conduction along myelinated axons relies on the node of Ranvier. How nodes assemble on CNS neurons is not yet fully understood. We recently highlighted that clusters similar to nodes can form prior to myelin deposition in hippocampal GABAergic neurons and are associated with increased conduction velocity. Here, we used a live imaging approach to characterize the intrinsic mechanisms underlying the assembly of these early clusters. We first demonstrated that their components can partially pre-assemble prior to membrane targeting and determined the molecular motors involved in their trafficking. We then demonstrated the key role of the protein {beta}2Nav for clustering initiation. We further unraveled the fate of these early clusters, by showing that they participate in node formation, but also have an unexpected role in guiding oligodendrocyte processes prior to myelin deposition. Altogether our results shed light on an alternative mechanism of nodal clustering and myelination onset.

neuroscience↗