After amputation, axolotl salamanders can regenerate their limbs, but the degree to which limb regeneration recapitulates limb development remains unclear. One limitation in answering this question is our lack of knowledge about salamander limb development. Here, we address this question by studying expression patterns of genes important for limb patterning during axolotl salamander limb development and regeneration. We focus on the Wnt signaling pathway because it regulates multiple functions during tetrapod limb development, including limb bud initiation, outgrowth, patterning, and skeletal differentiation. We use fluorescence in situ hybridization to show the expression of Wnt ligands, Wnt receptors, and limb patterning genes in developing and regenerating limbs. Inhibition of Wnt ligand secretion permanently blocks limb bud outgrowth when treated early in limb development. Inhibiting Wnt signaling during limb outgrowth decreases the expression of critical signaling genes, including Fgf10, Fgf8, and Shh, leading to the reduced outgrowth of the limb. Patterns of gene expression are similar between developing and regenerating limbs. Inhibition of Wnt signaling during regeneration impacted patterning gene expression similarly. Overall, our findings suggest that limb development and regeneration utilize Wnt signaling similarly. It also provides new insights into the interaction of Wnt signaling with other signaling pathways during salamander limb development and regeneration.
|Journal||Frontiers in Cell and Developmental Biology|
|State||Published - Apr 21 2022|
Bibliographical noteFunding Information:
This work was funded by the National Science Foundation (grants 1558017 and 1656429) and NIH grants 3OT2OD024909-01S3, R24OD021479, and R01HD099174.
We thank the Institute for Chemical Imaging of Living Systems at Northeastern University for consultation and imaging support. We thank Michelle Southard-Smith and Aaron May-Zhang from Vanderbilt University School of Medicine for assistance in developing HCR probe design pipelines. Non-transgenic animals were obtained from the Ambystoma Genetic Stock Center funded through NIH grant P40OD019794.
Copyright © 2022 Lovely, Duerr, Qiu, Galvan, Voss and Monaghan.
- limb development
- limb regeneration
ASJC Scopus subject areas
- Developmental Biology
- Cell Biology