m6A deficiency impairs hypothalamic neurogenesis of feeding-related neurons in mice and human organoids and leads to adult obesity in mice

N⁶-methyladenosine (m⁶A), the most prevalent internal modification on mRNAs, plays important roles in the nervous system. Whether neurogenesis in the hypothalamus, a region critical for controlling appetite, is regulated by m⁶A signaling, especially in humans, remains unclear. Here, we showed that deletion of m⁶A writer Mettl14 in the mouse embryonic hypothalamus led to adult obesity, with impaired glucose-insulin homeostasis and increased energy intake. Mechanistically, deletion of Mettl14 leads to hypothalamic arcuate nucleus neurogenesis deficits with reduced generation of feeding-related neurons and dysregulation of neurogenesis-related m⁶A-tagged transcripts. Deletion of m⁶A writer Mettl3 or m⁶A reader Ythdc1 shared similar phenotypes. METTL14 or YTHDC1 knockdown also led to reduced generation of feeding-related neurons in human brain subregion-specific arcuate nucleus organoids. Our studies reveal a conserved role of m⁶A signaling in arcuate nucleus neurogenesis in mice and human organoids and shed light on the developmental basis of epitranscriptomic regulation of food intake and energy homeostasis.