A light-softened gel enabled researchers to control crypt fission in three-dimensional models of mouse intestinal tissue
A light-softened gel enabled researchers to control crypt fission in three-dimensional models of mouse intestinal tissue
On 29 August, Advanced Science published a study of mouse intestinal organoids, which are three-dimensional cellular models of tissue. The researchers used light to control the initial crypt shape and the timing of its separation into two daughter crypts. They then measured the association between crypt shape and fission symmetry.
Crypts are invaginations in the intestinal lining that contain stem cells. As the intestine grows or repairs damage, one crypt can divide into two daughter crypts. In conventional organoids, crypt fission begins at random, which makes it difficult to track a single structure from its initial shape to the final outcome.
The authors embedded the organoids in a soft gel that a laser can soften locally. They first used the laser to create a channel for one crypt. Three days later, they created two V-shaped channels at its base. The tissue grew into the softened regions. This approach allowed the researchers to control when and where fission occurred and to observe a single crypt until two daughter crypts emerged.
Across seven experiments, the researchers studied 184 organoids, and about 70% formed daughter crypts. Among successful fission events, approximately 85% had a short-to-long daughter crypt length ratio of at least 0.7, the authors' chosen threshold for symmetry. The team then compared primary channels measuring 50 and 70 micrometers in width. The narrower channel produced a more curved initial crypt and resulted in symmetric fission more often, while the mean daughter crypt length remained unchanged.
Epithelial regions with greater curvature showed a stronger signal for active myosin II, a protein that helps cells contract. When the researchers conditionally inactivated Myh9, the gene encoding nonmuscle myosin IIA, during fission, symmetry decreased at both channel widths. In this controlled system, the authors linked epithelial shape and curvature with myosin activity and the symmetry of the two daughter crypts.
In a 2025 study, some members of the current team had already used a light-responsive gel to alter crypt shape and Paneth cell positioning. The current study applies this method to alter the geometry of a mature crypt before fission and compare it with the shapes of the two daughter crypts.