The role of gsc and BMP-4 in dorsal-ventral patterning of the marginal zone in Xenopus: a loss-of-function study using antisense RNA.

AUTOR(ES)

Steinbeisser, H

RESUMO

The dorsal-specific homeobox gene goosecoid (gsc) and the bone morphogenetic protein 4 gene (BMP-4) are expressed in complementary regions of the Xenopus gastrula. Injection of gsc mRNA dorsalizes ventral mesodermal tissue and can induce axis formation in normal and UV-ventralized embryos. On the other hand, BMP-4 mRNA injection, which has a strong ventralizing effect on whole embryos, has been implicated in ventralization by UV, and can rescue tail structures in embryos dorsalized by LiCl. The above-mentioned putative roles for BMP-4 and gsc are based on gain-of-function experiments. In order to determine the in vivo role of these two genes in the patterning of the Xenopus mesoderm during gastrulation, partial loss-of-function experiments were performed using antisense RNA injections. Using marker genes that are expressed early in gastrulation, we show that antisense gsc RNA has a ventralizing effect on embryos, whereas antisense BMP-4 RNA dorsalizes mesodermal tissue. These loss-of-function studies also show a requirement for gsc and BMP-4 in the dorsalization induced by LiCl and in the ventralization generated by UV irradiation, respectively. Thus, both gain- and loss-of-function results for gsc and BMP-4 support the view that these two genes are necessary components of the dorsal and ventral patterning pathways in Xenopus embryos.

Documentos Relacionados

• On the function of BMP-4 in patterning the marginal zone of the Xenopus embryo.
• Human BMP sequences can confer normal dorsal-ventral patterning in the Drosophila embryo.
• A truncated bone morphogenetic protein receptor affects dorsal-ventral patterning in the early Xenopus embryo.
• The maternal JAK/STAT pathway of Drosophila regulates embryonic dorsal-ventral patterning
• Dorsal-ventral patterning of the spinal cord requires Gli3 transcriptional repressor activity