Antagonizing the Spemann organizer: role of the homeobox gene Xvent-1.
We have identified a novel homeobox gene, Xvent-1, that is differentially expressed in the ventral marginal zone of the early Xenopus gastrula. Evidence is presented from mRNA microinjection experiments for a role for this gene in dorsoventral patterning of mesoderm. First, Xvent-1 is induced by BMP-4, a gene known to be a key regulator of ventral mesoderm development. Second, Xvent-1 and the organizer-specific gene goosecoid are able to interact, directly or indirectly, in a cross-regulatory loop suppressing each other's expression, consistent with their mutually exclusive expression in the marginal zone. Third, microinjection of Xvent-1 mRNA ventralizes dorsal mesoderm. The results suggest that Xvent-1 functions in a ventral signaling pathway that maintains the ventral mesodermal state and antagonizes the Spemann organizer.
Gawantka
V
V
Division of Molecular Embryology, German Cancer Research Center, Heidelberg, Germany.
Delius
H
H
Hirschfeld
K
K
Blumenstock
C
C
Niehrs
C
C
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D003001:Cloning, Molecular; D017931:DNA Primers / Q000235:genetics; D018076:DNA, Complementary / Q000235:genetics; D005775:Gastrula / Q000378:metabolism; D018507:Gene Expression Regulation, Developmental; D005801:Genes, Homeobox; D006257:Head / Q000196:embryology; D018398:Homeodomain Proteins / Q000235:genetics*; D017403:In Situ Hybridization; D008648:Mesoderm / Q000378:metabolism; D008845:Microinjections; D008969:Molecular Sequence Data; D009672:Notochord / Q000196:embryology; D012333:RNA, Messenger / Q000008:administration & dosage / Q000235:genetics; D014981:Xenopus / Q000196:embryology / Q000235:genetics
D017931:DNA Primers; D018076:DNA, Complementary; D018398:Homeodomain Proteins; D012333:RNA, Messenger