MicroRNAs (miRNAs) are small non-coding RNAs that regulate gene expression by binding
to their target mRNAs. Mice with ablation of Dicer in the lung epithelium show abnormal
lung branching and growth indicating a critical role of the miRNAs machinery during
lung morphogenesis. We have investigated miRNAs expression in the embryonic lung and
identified miRNAs specifically enriched in the epithelium versus mesenchyme. The role
of specific miRNAs was analyzed with embryonic lung organ cultures by loss of function
of specific miRNAs using morpholinos. We have specifically screened for miRNAs that
contribute to the regulation of FGF and WNT signaling in the embryonic mesenchyme.
Modulation of the branching, and effects on cell proliferation and differentiation
were used as a readout.
