Opposing FGF and Retinoid Pathways Control Ventral Neural Pattern, Neuronal Differentiation, and Segmentation during Body Axis Extension

摘要: Vertebrate body axis extension involves progressive generation and subsequent differentiation of new cells derived from a caudal stem zone; however, molecular mechanisms that preserve progenitors coordinate are poorly understood. FGF maintains its attenuation is required for neuronal mesodermal to position segment boundaries. Furthermore, somitic mesoderm promotes in part by downregulating Fgf8. Here we identify retinoic acid (RA) as this signal show retinoid pathways have opposing actions. general repressor differentiation, including ventral neural patterning, while RA attenuates Fgf8 neuroepithelium paraxial mesoderm, where it controls somite boundary position. further expression key patterning genes. Our data demonstrate mutually inhibitory suggest their actions provide global mechanism during extension.