Twisted gastrulation can function as a BMP antagonist

Area of Science:

• Developmental Biology
• Molecular Biology
• Genetics

Background:

• Bone morphogenetic proteins (BMPs) are crucial for establishing the dorsal-ventral axis in both vertebrates and invertebrates.
• Secreted factors like chordin/Short gastrulation (SOG) antagonize BMP activity, but the role of Twisted gastrulation (TSG) in vertebrates remained unclear.

Purpose of the Study:

• To characterize vertebrate Twisted gastrulation (TSG) homologues.
• To elucidate the mechanism of TSG function in vertebrate development, specifically in Xenopus.

Main Methods:

• Embryonic explant assays in Xenopus to assess BMP inhibition.
• Whole-frog embryo experiments to evaluate effects on developmental markers.
• Biochemical assays to determine TSG binding interactions with BMPs and chordin.

Main Results:

• Vertebrate TSG homologues were characterized.
• TSG demonstrated BMP inhibitory function in Xenopus embryonic explants and inhibited ventral markers in whole embryos.
• TSG directly binds BMPs, forming a ternary complex with chordin, enhancing BMP inhibition.

Conclusions:

• TSG functions as a BMP inhibitor in Xenopus, playing a role in dorsal-ventral axis determination.
• TSG may possess additional, yet uncharacterized, functions during frog embryogenesis.
• The findings suggest conserved roles for TSG in BMP pathway regulation across species.