Table 2. Mutations in previously uncharacterized genes that alter dorsal-ventral patterning of the spinal cord.

Mutant	Phenotype	Map position (Chr; cM)	Gene (ref.)
open brain (opb2)	Exencephaly, ventralized caudal spinal cord, polydactyly, die at e13-14	1: 18.5	Rab 23 (23)
wimple (wim)	Exencephaly, dorsalized spinal cord, left-right randomization; die at e10-11	5: 16-18	IFT172 (13)
hennin (hnn)	No floor plate in caudal spinal cord, left-right randomization; die at e13-14	16: 36-42	Novel*
icbins (icb)	Dorsalized spinal cord, left-right randomization; die at e9.0	1: 102	Disp1 (19)
ling-ling (lln)	Dorsalized spinal cord, left-right randomization; die at e10-11	9: 0-7.5	Dnchc2†
sister of open brain (sopb)	Exencephaly, ventralized caudal spinal cord, polydactyly; die at e13-14	6: 50.5-60.5

^*T.C. and K.V.A., unpublished results.

^†D.H. and K.V.A., unpublished results.