Identification of the hypothalamic neuronal populations that derive from Pomc-expressing precursors

Hypothalamic neuronal populations are central regulators of energy homeostasis and reproductive function. However, the ontogeny of these critical hypothalamic neuronal populations is largely unknown. Here, we reveal novel cellular fates of the hypothalamic Pomc-expressing precursors by combining mouse genetics with a conditional viral ribosome-tagging approach to phenotype neurons. Our results show that the Pomc-expressing precursors differentiate into discrete neuronal subpopulations that mediate not only energy balance (POMC and AgRP) but also reproductive physiology (Kisspeptin). Punches containing the mediobasal hypothalamus of Pomc-Cre:RiboTag mice and Pomc-Cre mice injected with the RiboTag viral vector (AAV-DIO-RiboTag) were homogenized and incubated with anti-hemagglutin (HA) antibodies and protein A/G magnetic beads to isolate the polysome-associated mRNAS in the Pomc-derived lineage and in adult POMC neurons, respectively. To identify differentially expressed transcripts, RNA from the immunoprecipitates was extracted, amplified, labelled and hybridized to MouseRef-8 v2 expression beadchips.