The Synthesis of GABA during the Tailbud Stage Is Required for Axial Elongation in Xenopus laevis embryos

In Xenopus laevis , axial elongation beyond the tailbud stage requires gamma-aminobutyric acid (GABA). However, the role of GABA synthesized during early development in this process remains unclear. In this study, by treating embryos with allylglycine (AG), an inhibitor of GABA synthesis, we observed a significant reduction in axial elongation. This inhibition was rescued by exogenous GABA, demonstrating that GABA synthesis via glutamate decarboxylase (GAD) is essential for axial elongation after the tailbud stage. Our findings suggest that GABA-dependent elongation functions independently of mechanisms like convergent extension, which are crucial during early development.