A-J: Igsf10 expression was not observed at E10.5 (A, sagittal section) but readily detectable at E12.5, in the NM (B and C, frontal sections) and E14.5, along the migratory path of GnRH neurons (D, frontal section). Igsf10 positive cells were negative for Isolectin b4 (marker of vasculature) at all developmental stages (E, at E14.5). Incubation with the sense probe resulted in no signal at all stages (E14.5 shown in F). Peripherin-positive cells olfactory axons were extending within the Igsf10-positive NM (G and H). Cxcl12 mRNA expression is shown in I (E14.5, frontal section). GnRH neurons are located in the MPOA by E17.5 (J, frontal section) in an Igsf10 negative area. 