Cell‐autonomous signal transduction in the Xenopus egg Wnt/β‐catenin pathway

Abstract

Wnt proteins are thought to bind to their receptors on the cell surfaces of neighboring cells. Wnt8 likely substitutes for the dorsal determinants in Xenopus embryos to dorsalize early embryos via the Wnt/β-catenin pathway. Here, we show that Wnt8 can dorsalize Xenopus embryos working cell autonomously. Wnt8 mRNA was injected into a cleavage-stage blastomere, and the subcellular distribution of Wnt8 protein was analyzed. Wnt8 protein was predominantly found in the endoplasmic reticulum (ER) and resided at the periphery of the cells; however, this protein was restricted to the mRNA-injected cellular region as shown by lineage tracing. A mutant Wnt8 that contained an ER retention signal (Wnt8-KDEL) could dorsalize Xenopus embryos. Finally, Wnt8-induced dorsalization occurred only in cells injected with Wnt8mRNA. These experiments suggest that the Wnt8 protein acts within the cell, likely in the ER or on the cell surface in an autocrine manner for dorsalization.

Integrated lncRNA and mRNA Transcriptome Analyses in the Ovary of Cynoglossus semilaevis Reveal Genes and Pathways Potentially Involved in Reproduction

“…We found that antisense and cis -target genes were enriched in the cell cycle, in processes including apoptosis and signaling pathways such as the TGF-beta signaling pathway and the Wnt signaling pathway. Several studies have shown that the TGF-beta signaling pathway and Wnt signaling pathway are involved in a broad spectrum of cellular functions, such as proliferation, apoptosis, differentiation, migration, and embryogenesis ( Motomura et al, 2014 ; Yu et al, 2020 ). TGF-beta signals can lead to avian ovary granulosa cell proliferation mediated by signals transduced by the cytoplasmic signal transducer Smad ( Schmierer et al, 2003 ).…”