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

Abstract 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 12 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 have altered hypothalamic patterning, and in doing so, have identified multiple genes that simultaneously repress posterior hypothalamic identity while promoting prethalamic identity. This result supports a modified columnar model of organization for the diencephalon, where prethalamus and hypothalamus are situated in adjacent dorsal and ventral domains of the anterior diencephalon. These data serve as a resource for further studies of hypothalamic development, physiology and dysfunction.