Four Jointed Box Protein 1 (FJX1)

Northern blot analysis identified a 2.8-kb Fjx1 transcript throughout development beginning at E11 and in adult brain. A weaker 1.7-kb transcript was detected at E7, but not during later stages of development. During mouse embryonic development, Fjx1 was expressed in the midbrain tectum and in telencephalic vesicles.

In fetal and early postnatal brain, Fjx1 was expressed mainly in the primordia of layered telencephalic structures and in the superior colliculus. It was also expressed in the apical ectodermal ridge of fore- and hindlimbs and in the ectoderm of the branchial arches. In the adult, Fjx1 was expressed in neurons of the telencephalon, in the Purkinje layer of the cerebellum, and in numerous medullary nuclei.