A neuroepithelial wave of BMP signalling drives anteroposterior specification of the tuberal hypothalamus

The tuberal hypothalamus houses several major hypothalamic nuclei, dozens of transcriptionally distinct cell types, and clinically relevant cell populations implicated in obesity and related metabolic disorders. Building on recent advances in the field, here we draw upon transcriptional, signalling, and fate mapping analyses of chicken embryos and neuroepithelial explants to analyze tuberal hypothalamic development. We show that a wave of BMP signalling sweeps through early floor plate-like progenitors overlying prospective Rathkes pouch as they track anteriorly. The timing of BMP signalling correlates with cell fate, with anterior tuberal specification complete by Hamilton-Hamburger (HH) stage 10 but posterior tuberal progenitors requiring BMPs after this point. scRNA-Seq profiling of FGF10-expressing cells, a proxy for cells with active BMP signalling, through HH8-21 reveals transcriptional differences that may underlie their differing response to BMPs, and the switch from neuroepithelial progenitors to stem-like radial glial cells. This study provides an integrated account of the development of the tuberal hypothalamus.