Evx1 is a mammalian gene located downstream of the HoxA cluster, which encodes for a homeobox transcription factor. Evx1 is a homolog of even-skipped (eve), which is a pair-rule gene that regulates body segmentation in Drosophila.[1][2] The expression of Evx1 is developmentally regulated, displaying a biphasic expression pattern with peak expression in the primitive streak during gastrulation and in interneurons during neural development.[3][4] Evx1 has been shown to regulate anterior-posterior patterning during gastrulation by acting as a downstream effector of the Wnt and BMP signalling pathways.[4][5] It is also a critical regulator of interneuron identity.[6]
Despite a regulatory role in both of these processes, the Evx1 KO mouse is viable and displays no overt phenotype after birth.[4][6]
A divergent long non-coding RNA (Evx1as) is also expressed from the locus, which is temporally and spatially co-expressed with Evx1.[3][4][7] Evx1as does not have a function beyond that of Evx1 (in trans);[4] however, it has been shown to regulate Evx1 at the locus (in cis).[7]