“…Similarly, the non-overlapping sets of upstream regulators, Dlx1, Otp, Sim1, Satb2 and Arnt2 for DA neurons ( Biran et al, 2015 ; Orquera et al, 2016 ; Yee et al, 2009 ; Zhang et al, 2021a ), and Dbx1, Ebf2 and Lhx9 for Hcrt neurons ( Dalal et al, 2013 ; De La Herran-Arita et al, 2011 ; Liu et al, 2015 ; Sokolowski et al, 2015 ), also argue against a common origin, as well as against a common genetic pathway. Interestingly, knockout of the H3K4-methyltransferase Mll4 ( Kmt2d ) gene in the developing hypothalamic arcuate nucleus also resulted in highly selective effects on neuronal subtype specification ( Huisman et al, 2021 ).…”