The transmembrane protein Syndecan regulates stem cell nuclear properties and cell maintenance

Tissue maintenance is underpinned by resident stem cells whose activity is modulated by microenvironmental cues. UsingDrosophilaas a simple model to identify regulators of stem cell behaviour and survivalin vivo, we have identified novel connections between the conserved transmembrane proteoglycan Syndecan, nuclear properties and stem cell function. In theDrosophilamidgut, Syndecan depletion in intestinal stem cells results in their loss from the tissue, impairing tissue renewal. At the cellular level, Syndecan depletion alters cell and nuclear shape, and causes nuclear lamina invaginations and DNA damage. In a second tissue, the developingDrosophilabrain, live imaging revealed that Syndecan depletion in neural stem cells results in nuclear envelope remodelling defects which arise upon cell division. Our findings reveal a new role for Syndecan in the maintenance of nuclear properties in diverse stem cell types.