Cleft formation and Btbd7. (A to C) Formation of clefts in a submandibular gland at E12.5 (A) or in glands cultured for 5 h (B), or 10 h (C). Fixed samples were stained with anti E-cadherin antibody (red) and DAPI (blue). Clefts (open triangles), basement membrane (white line), and E-cadherin (white dashed line) at cell boundaries of outer epithelial cells. (D) Cleft progression by transient gap formation as visualized by tetramethylrhodamine-labeled dextran; e, epithelium; m, mesenchyme. (E) Diagram of laser microdissected developing salivary gland (red, cleft; blue, bud region). (F and G) Btbd7 mRNA expression by qPCR in developing embryonic and postnatal salivary glands (F) and in other organs (G). Scale bar: 10 µm.