DVR-4 (Bone Morphogenetic Protein-4) as a posterior-ventralizing factor in <i>Xenopus</i> mesoderm induction

TLDR

Mesodermal tissues in amphibians arise through inductive interactions among peptide growth factors that shape the embryonic body plan. DVR‑4, a TGF‑β–like factor, induces posterior/ventral mesoderm, overrides activin’s dorsalizing effect, and is the first molecule shown to promote posteroventral mesoderm while antagonizing dorsal signals.

Abstract

Establishment of mesodermal tissues in the amphibian body involves a series of inductive interactions probably elicited by a variety of peptide growth factors. Results reported here suggest that mesodermal patterning involves an array of signalling molecules including DVR-4, a TGF-beta-like molecule. We show that ectopic expression of DVR-4 causes embryos to develop with an overall posterior and/or ventral character, and that DVR-4 induces ventral types of mesoderm in animal cap explants. Moreover, DVR-4 overrides the dorsalizing effects of activin. DVR-4 is therefore the first molecule reported both to induce posteroventral mesoderm and to counteract dorsalizing signals such as activin. Possible interactions between these molecules resulting in establishment of the embryonic body plan are discussed.