Figure 9
Latent TGFβ binding protein ( Ltbp ) 1L is silent in secretory alveoli during pregnancy. (A-D) The 5-bromo-4-chloro-3-indolyl-β-D-galactoside (X-Gal)-stained whole mounts show Ltbp1L-LacZ (blue stain) is expressed in ducts and side branches at all stages of pregnancy, but absent from alveoli. (A) Carmine/X-Gal-stained whole mount P13.5. (B) Ltbp1L-LacZ is expressed in a reticular staining pattern demarcating a subset of ductal cells. (C) Carmine/X-Gal-stained whole mount P14.5 (D) X-Gal-stained whole mount P14.5. (E, F) nuclear fast red(NFR)/X-Gal-stained sections P16.5 show Ltbp1L-LacZ is expressed in ducts but not in adjacent alveoli. Scale bars represent distance in microns.