Lung development in laminin γ2 deficiency: abnormal tracheal hemidesmosomes with normal branching morphogenesis and epithelial differentiation

Laminin-332 is prominent in the basement membrane of alveolar walls and airways of developing and adult lung. A function for laminin γ2 in lung development has been hypothesized. Compared to littermate controls, Lamc2-/- lungs were similar in morphology during embryonic life. Epithelial differentiation did not reveal a difference between Lamc2-/- and littermate control lungs. Likewise, vascular development, smooth muscle cell differentiation, and elastic fiber formation looked similar, as did airway basement membrane ultrastructure. Branching morphogenesis by lung bud culture was similar in Lamc2-/- and littermate control lungs. These findings indicate that laminin γ2 and laminin-332, despite their prominence in the lung, have a minimal role in lung development through the saccular stage.