Fig. 4

Prediction of TSPEAR function

(A) Heatmap of pairwise sequence identities using cDNA sequences for 45 diverse species. Note the broad conservation in vertebrates and distinct triangles for mammals, birds, and fish.

(B) AlphaFold-predicted structures for both Drosophila Closca and TSPEAR; note a predicted β-propeller in both.

(C) Schematic of the known function of Closca in both Torso and Toll receptor activation and terminal and dorsoventral patterning, respectively. Closca, along with Nusrat and Polehole, sequester Torso-like (tsl) and also Nudel at the vitelline membrane (VM), allowing for their precise spatial and temporal accumulation and release, which transfers spatial information to the developing embryo. PM, plasma membrane; PVS, perivitelline space.

(D) scRNA-seq data in the murine developing molar showing restricted expression of Tspear to the enamel knot, an important signaling center.