NEGATIVE REGULATION OF DORSAL PATTERNING IN EARLY EMBRYOS BY OVEREXPRESSION OF XRE1A, A XENOPUS HOMOLOG OF NF-KAPPA-B

Recent results by Richardson et al. (Mech. Dev., 52 (1995) 165-177) su ggest that the Xenopus Rel gene XrelA may be involved in the formation of the head and tail of the early embryo. We present evidence to sugg est that wild-type XrelA also has a role in dorsoventral development. XrelA overexpression in the dorsal side of embryos reduces dorsal deve lopment and attenuates in vitro dorsal morphogenetic movements. XrelA also strongly reduces axis duplication caused by overexpression of a d ominant negative mutant of Xenopus glycogen synthase kinase-3 beta. Ou r results indicate that XrelA may have a role in dorsoventral patterni ng in early embryos.