biostudies-literaturePackard ANational Institutes of Healthdev199386https://www.ebi.ac.uk/biostudies/studies/S-EPMC8214802biostudies-literatureUnknown148(9)Ret signaling promotes branching morphogenesis during kidney development, but the underlying cellular mechanisms remain unclear. While Ret-expressing progenitor cells proliferate at the ureteric bud tips, some of these cells exit the tips to generate the elongating collecting ducts, and in the process turn off Ret. Genetic ablation of Ret in tip cells promotes their exit, suggesting that Ret is required for cell rearrangements that maintain the tip compartments. Here, we examine the behaviors of ureteric bud cells that are genetically forced to maintain Ret expression. These cells move to the nascent tips, and remain there during many cycles of branching; this tip-seeking behavior may require positional signals from the mesenchyme, as it occurs in whole kidneys but not in epithelial ureterDevelopment (Cambridge, England)Ret signaling in ureteric bud epithelial cells controls cell movements, cell clustering and bud formation.PMC82148025R01DK083289Klein WHCostantini FPackard AfalseRet signaling in ureteric bud epithelial cells controls cell movements, cell clustering and bud formation.Ret signaling promotes branching morphogenesis during kidney development, but the underlying cellular mechanisms remain unclear. While Ret-expressing progenitor cells proliferate at the ureteric bud tips, some of these cells exit the tips to generate the elongating collecting ducts, and in the process turn off Ret. Genetic ablation of Ret in tip cells promotes their exit, suggesting that Ret is required for cell rearrangements that maintain the tip compartments. Here, we examine the behaviors of ureteric bud cells that are genetically forced to maintain Ret expression. These cells move to the nascent tips, and remain there during many cycles of branching; this tip-seeking behavior may require positional signals from the mesenchyme, as it occurs in whole kidneys but not in epithelial ureter2021-01-01T00:00:00Z2021 May2025-04-05T10:03:18.361Z2025-04-05T10:03:18.361ZS-EPMC82148023391486510.1242/dev.199386