Biology subjects

Briand, D.

Publications and source records attributed to Briand, D..

2 recordsLinked to original sources

bioRxiv2024

Adhesion-Controlled Mechanics of the Glial Niche Regulate Neural Stem Cell Proliferative Potential

Controlled proliferation of neural stem cells (NSCs) builds a functional nervous system during development. While their cellular niche is recognized as a signalling hub, the contribution of its structure and mechanics in regulating neurogenesis remains unexplored. The Drosophila larval central nervous system contains self-renewing NSCs in close contact with cortex glial cells. Transcriptomics identified a triad of immunoglobulin superfamily cell adhesion molecules (Dpr10/Dpr6 in glia and DIP- in NSCs) which physically and mechanically connect the NSC and glial membranes, acting as mechanoregulators. Their disruption increases glial cortical tension, causing non-autonomous mitotic defects in NSCs, characterized by abnormal spindle morphologies and impaired mitotic progression. Additionally, elevated glial tensile forces increase Lamin content in NSCs, a protective response also resulting in nuclear deformation. Ultimately NSC proliferative potential and genome integrity are compromised. Our study reveals that the native mechanical properties of the niche are transmitted to NSCs and regulate their function. Graphical abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=156 SRC="FIGDIR/small/628019v1_ufig1.gif" ALT="Figure 1"> View larger version (47K): org.highwire.dtl.DTLVardef@18137f8org.highwire.dtl.DTLVardef@819740org.highwire.dtl.DTLVardef@1f0ed0forg.highwire.dtl.DTLVardef@5ba0e4_HPS_FORMAT_FIGEXP M_FIG C_FIG

developmental biology↗

bioRxiv2022

A corset of adhesions during development establishes individual neural stem cell niches and controls adult behaviour

Neural stem cells (NSCs) reside in a defined cellular microenvironment, the niche, which supports the generation and integration of neuronal lineages. The mechanisms building a sophisticated niche structure around NSCs, and their functional relevance for neurogenesis are yet to be understood. In the Drosophila larval brain, the cortex glia (CG) encase individual NSC lineages, organizing the stem cell population and newborn neurons into a stereotypic structure. We first found that lineage information is dominant over stem cell fate. We then discovered that, in addition to timing, the balance between multiple adhesion complexes supports the individual encasing of NSC lineages. An intra-lineage adhesion through homophilic Neuroglian interactions provides strong binding between cells of a same lineage, while a weaker interaction through Neurexin-IV exists between CG to NSC lineages. Their loss leads to random, aberrant grouping of several NSC lineages together, and to altered axonal projection of newborn neurons. Further, we link the loss of these two adhesion complexes during development to locomotor hyperactivity in the resulting adults. Altogether, our findings identify a corset of adhesions building a neurogenic niche at the scale of individual stem cell and provide the proof-of-principle that mechanisms supporting niche formation during development define adult behaviour.

developmental biology↗