Left-right (LR) asymmetry is a fundamental feature of internal anatomy, yet the emergence of morphological asymmetry remains one of the least understood phases of organogenesis. Asymmetric rotation of the intestine is directed by forces outside the gut, but the morphogenetic events that generate anatomical asymmetry in other regions of the digestive tract remain unknown. Here, we show in mouse and Xenopus that the mechanisms that drive the curvature of the stomach are intrinsic to the gut tube itself. The left wall of the primitive stomach expands more than the right wall, as the left epithelium becomes more polarized and undergoes radial rearrangement. These asymmetries exist across several species, and are dependent on LR patterning genes, including Foxj1, Nodal and Pitx2. Our findings have implications for how LR patterning manifests distinct types of morphological asymmetries in different contexts.
The authors declare no competing or financial interests.
A.D., N.M.A., C.J. and K.B. performed experiments; N.N.-Y. conceived of the project and wrote manuscript; H.T.G. provided mouse strains.
This work was supported by the National Institutes of Health (R01DK085300 and R21OD017963 to N.N-Y., R01NS062182 to H.T.G, T32ES007046 to A.D.). Deposited in PMC for release after 12 months.
Supplementary information available online at http://dev.biologists.org/lookup/doi/10.1242/dev.143701.supplemental
- Received August 15, 2016.
- Accepted February 21, 2017.