Single cell RNA-Seq identifies mechanisms controlling hypothalamic patterning and differentiation

The hypothalamus is a central regulator of many innate behaviors that are essential for survival, but the molecular mechanisms controlling hypothalamic patterning and cell fate specification remain poorly understood. To identify genes that control hypothalamic development, we have used single-cell RNA sequencing (scRNA-Seq) to profile mouse hypothalamic gene expression across 11 developmental time points between embryonic day 10 and postnatal day 45.  This identified genes that delineated clear developmental trajectories for all major hypothalamic cell types and readily distinguished major regional subdivisions of the developing hypothalamus. We show that this approach can rapidly and comprehensively characterize mutants that control hypothalamic patterning and, in doing so, identify multiple genes that simultaneously repress posterior hypothalamic identity while promoting prethalamic identity. This argues in favor of a modified columnar organization of hypothalamus and prethalamus. These data serve as a resource for further studies of hypothalamic development, physiology, and dysfunction.