Role of alpha 6 integrin subunit in branching morphogenesis of fetal mouse submandibular gland: investigation by mesenchyme-free epithelial culture system.

The submandibular gland (SMG) of the fetal mouse is a well-studied model for the epithelial-mesenchymal interactions required for branching morphogenesis (BrM), which involves cleft formation and stalk elongation. In a previous report, we showed that alpha 6 integrin subunit is involved in BrM of this gland rudiment, since the neutralizing antibody against alpha 6 integrin subunit, GoH3, strongly inhibited branching of cultured intact E13 SMG. In this study, we investigated whether GoH3 inhibits cleft formation and/or stalk elongation during BrM of cultured mesenchyme-free epithelial rudiments of fetal SMG and also analyzed by Western blotting the levels of phosphorylation of ERK1/2, which is a signaling molecule known to regulate BrM of the fetal mouse SMG.