Project description:The canonical Wnt/β-catenin signaling pathway plays multiple roles during Xenopus gastrulation, including posteriorization of the neural plate, patterning of the mesoderm, and induction of the neural crest. Wnt signaling stabilizes β-catenin, which then activates target genes. However, few targets of this signaling pathway that mediate early developmental processes are known. Here we sought to identify transcriptional targets of the Wnt/β-catenin signaling pathway using a genome-wide approach.
Project description:The canonical Wnt/β-catenin signaling pathway plays multiple roles during Xenopus gastrulation, including posteriorization of the neural plate, patterning of the mesoderm, and induction of the neural crest. Wnt signaling stabilizes β-catenin, which then activates target genes. However, few targets of this signaling pathway that mediate early developmental processes are known. Here we sought to identify transcriptional targets of the Wnt/β-catenin signaling pathway using a genome-wide approach.
Project description:During Xenopus gastrulation, dorsal stabilization of β-Catenin at the earliest stage and subsequent target genes expression are critical for dorsal-ventral axis determination. However, many β-Catenin targets that mediate this process are still unkown. Here through RNA-seq analysis of β-Catenin knockdown embryos and self-regulating dorsal and ventral half embryos at early gastrula, we define an early β-Catenin gene signature that is downregulated by β-Catenin MO and enriched in dorsal gastrula tissues. This gene signature includes classic Spemann organizer genes, as well as other novel genes. Further analyses revealed that the early β-Catenin gene signature is positively correlated with LiCl treated, Wnt8 and Siamois mRNA-induced genes, consistent with their early role in dorsal-ventral axis formation. Our results also show that St 10.5 is the appropriate stage to uncover β-Catenin target genes that regulate dorsal-ventral patterning than St 9. Meanwhile, the multi-growth factor antagonist Cerberus inhibits part of the early β-Catenin gene signature and also controls the expression of a unique set of genes. Our findings provide new insight into the pivotal role of β-catenin in dorsal-ventral axis determination and can serve a fruitful resource for this field.