Ror2 is required for midgut elongation during mouse development
Makiko Yamada1, Jun Udagawa, Akihiro Matsumoto
1Department of Developmental Biology, Faculty of Medicine, Shimane University, Izumo, Japan. makiyamd@med.shimane-u.ac.jp
Abstract:
The receptor tyrosine kinase Ror2 acts as a receptor for Wnt5a to mediate noncanonical Wnt signaling, and it plays essential roles in morphogenesis. Ror2-/- embryos exhibit phenotypes similar to, albeit generally milder than, those of Wnt5a-/- embryos. During mouse embryogenesis, Ror2 is expressed in various organs and regions, although little is known about its expression pattern and roles in the developing gut, while Wnt5a is expressed in the developing gut, where its absence causes abnormal phenotypes. Here, we demonstrated that Ror2 was strongly and differentially expressed in the rostral and middle midgut endoderm from embryonic day (E) 10.5 through embryonic day (E) 12.5. At E11.5, Ror2-/- embryos exhibited a shorter middle midgut with a larger diameter and more accumulation of epithelial cells in the middle midgut than control embryos, while the total cell numbers remained unaltered. These findings suggest that Ror2 plays important roles in midgut elongation by means of an epithelial convergent extension mechanism.
Insights
The receptor tyrosine kinase Ror2 is crucial for midgut elongation in mouse embryos. Its absence leads to shorter midguts by affecting epithelial cell behavior through convergent extension.
Area of Science:
- Developmental Biology
- Molecular Biology
- Genetics
Background:
- Receptor tyrosine kinase Ror2 mediates noncanonical Wnt signaling and is vital for morphogenesis.
- Ror2 plays roles in various embryonic organs, but its function in the developing gut is largely unknown.
- Wnt5a is present in the developing gut and its absence causes abnormal phenotypes.
Purpose of the Study:
- To investigate the expression pattern and roles of Ror2 in the developing mouse gut.
- To elucidate the mechanism by which Ror2 influences gut development.
Main Methods:
- Analysis of Ror2 expression in mouse embryos from E10.5 to E12.5.
- Phenotypic analysis of Ror2-/- embryos at E11.5, focusing on midgut morphology and cell distribution.
Main Results:
- Ror2 showed strong, differential expression in the rostral and middle midgut endoderm.
- Ror2-/- embryos displayed a shorter middle midgut with increased epithelial cell accumulation and larger diameter.
- Total cell numbers in the middle midgut remained unchanged in Ror2-/- embryos.
Conclusions:
- Ror2 is essential for normal midgut elongation during mouse embryogenesis.
- Ror2 likely regulates midgut elongation via an epithelial convergent extension mechanism.
- These findings highlight a novel role for Ror2 in gut development.
