Figure 3.

TRPM7 but not TRPM6 is required for mediolateral intercalation. (a) Schematic illustration of mediolateral and radial intercalation. During gastrulation and neurulation, mesodermal and ectodermal cells move and exchange their positions with one another, which is referred to as cell intercalation. Depending on the direction of the cell movement, intercalation can be divided into mediolateral (upper illustration) and radial (lower illustration) intercalation. Black arrows indicate the direction of cell movement. Mediolateral intercalation results in tissue lengthening and narrowing, whereas radial intercalation results in tissue spreading as the number of layers are reduced (indicated solid green arrows). (b) A Keller explant assay was performed to investigate XTRPM6’s effect on mediolateral intercalation. The designated morpholinos or dominant negative Dishevelled (Xdd1) RNA were injected into two dorsal blastomeres of 4-cell stage embryos. The dorsal marginal zone, which undergoes mediolateral intercalation, was dissected at stage 10.5. Embryos injected with Xdd1, and the TRPM7 MO were used as positive controls for their inhibition of mediolateral intercalation. (c) Quantification of the results from Keller explant assay. Explants were scored by the ratio of length/width. The collective total number of injected embryos from all experiments is indicated above each bar. Error bars indicate standard error. *P = 0.017.