Foxf1 and SP-C contains a Cell-Type-Specific Transcriptional Activation Domain and is Expressed in Mouse Lungs

Abstract

Lung development in the mammal carries series of steps starting from simple lung buds to the elaborately branched organ that fulfil the vital function of gaseous exchange. Strict transcriptional control is essential for lung development. To screen the genes responsible for the regional growth and patterning we used RNA Insitu hybridization to identify genes that show restricted expression patterns in the embryonic lung. During organogenesis, the expression of Foxf1 becomes restricted to the splanchnic mesoderm, which provides the mesenchymal cells of the intestinal tract and gut derivates such as lungs and liver. Surfactant is a lipoprotein substance that is synthesized and secreted by alveolar type II epithelial cells and acts to reduce surface tension at the air-alveolar interface. SP-C a 5 kDa, hydro-phobic, surfactant-associated protein. We used the technique of in situ hybridization to localize SP-C mRNA in mice lung tissue. SP-C mRNA was present in all of the epithelial cells of the prealveolar region of day 13 gestational age mice lung tissue. Our data are suggestive that SP-C is present in fetal lung prealveolar epithelial cells much earlier in gestation than are differentiated, surfactant-producing alveolar type II cells.