Single-cell analysis of early chick hypothalamic development reveals that hypothalamic cells are induced from prethalamic-like progenitors

Abstract

Highlights d Early hypothalamic development was profiled in chick using scRNA-seq and HCR d Hypothalamic cells are induced from prethalamic-like cells d Distinct tuberal, mammillary, and paraventricular progenitor populations emerge later d Prethalamic-like progenitor-derived follistatin inhibits hypothalamic specification

SHH and Notch regulate SOX9+ progenitors to govern arcuate POMC neurogenesis

“…4942086001, Roche; 1 mg/ml in L15 medium at room temperature, 5–15 min). Prospective hypothalamus (pHyp) was dissected from HH6 to HH11 embryos, after early hypothalamic specification has been initiated ( Kim et al, 2022 ). Explants were embedded in collagen gels according to published techniques ( Ohyama et al, 2005 ) and cultured for 2 or 4 days in DMEM/F12 with Mito serum (BD, New Jersey, United States) and Glutamax (GIBCO).…”

“…The early neural marker SOX2 was also studied, itself also an EMT regulator ( Mandalos et al, 2014 ; He et al, 2017 ). The chick embryo was used due to its unparallelled suitability for studying early hypothalamic development ( Kim et al, 2022 ). From our immunostaining results, and backed up by analysis of a recent chicken scRNA-seq dataset ( Kim et al, 2022 ), we infer the sequential expression of SOX2, SOX9, PROX1, ISL1, and SOX11 in the anterior hypothalamus over the course of POMC neurogenesis.…”

“…The chick embryo was used due to its unparallelled suitability for studying early hypothalamic development ( Kim et al, 2022 ). From our immunostaining results, and backed up by analysis of a recent chicken scRNA-seq dataset ( Kim et al, 2022 ), we infer the sequential expression of SOX2, SOX9, PROX1, ISL1, and SOX11 in the anterior hypothalamus over the course of POMC neurogenesis. By perturbing SHH and Notch signalling in an ex vivo assay, we demonstrate that both pathways are required for the maintenance of SOX9+ cycling VZ progenitors upstream of POMC neuronal differentiation.…”

Accurate staging of chick embryonic tissues via deep learning

“…Importantly, studies show that disordered hypothalamus development promotes adult diseases, including obesity and stress related disorders (28)(29)(30)(31), and increasing numbers of studies are therefore beginning to focus on hypothalamic development. Recent studies in the chick show that the developing hypothalamus undergoes a significant expansion over HH10 (a period that encompasses ~5 hours), accompanied by subtle changes in its morphology (32,33). Molecular studies show that expansion of the early hypothalamus is accompanied by the first signs of its regionalisation into distinct functional domains (33).…”

“…Recent studies in the chick show that the developing hypothalamus undergoes a significant expansion over HH10 (a period that encompasses ∼5 hours), accompanied by subtle changes in its morphology (32, 33). Molecular studies show that expansion of the early hypothalamus is accompanied by the first signs of its regionalisation into distinct functional domains (33). This means that, for the accuracy of future experiments, it is important to develop a finer-grained classification of the HH10 hypothalamus.…”