RESUMEN
Alveoli are the key functional units of the lungs where gas exchange takes place, yet little is known about the mechanisms of their formation. To identify the genes that regulate alveolar morphogenesis, we used suppression subtractive hybridization to isolate genes that differentially expressed during the formation of saccules and the remodeling of saccules into alveoli in the mouse. After differential screening, we got 118 candidate genes from two libraries. These genes associate with many aspects of life including proliferation, differentiation, regulation and so on. For example: Transient receptor protein 4(TRPC4) may associate with formation or remodeling of pulmonary vessels by increasing permeability of endothelia cells. Lectin, (galactose bindingl, Lgalsl) may play a significant role in stimulating smooth muscle growth in developing alveolar wall vessels and the development of pulmonary capillaries. Interesting, a putative neuronalprotein, P311 was found highly expressed in both the first and the secondary septation stages. Taking together SSH is a powerful method to identify differential expressing genes.