Expression of miR-181 isoforms in primary LECs and BECs. (A) Quantification of miR-181 isoforms assessed by real-time RT-PCR in primary LECs and BECs isolated from (i) dermis at E16.5, (ii) dermis at E18.5, and (iii) adult ears. **P < .005. *P < .03. (Ai-ii) Data are mean ± SEM of 3 independent cell isolations from pools of 7 to 13 embryos each. (Aiii) Data are mean ± SEM of technical replicates for one isolation from 4 adult females and are representative of 3 independent experiments. P values were calculated using Student paired t test. (B) Quantification, as assessed by real-time RT-PCR, of (i) relative Prox1 mRNA levels and (ii) Pecam1 mRNA levels in LECs and BECs at indicated developmental time points. Data represent the fold difference in expression in LECs over BECs ± SEM; n = 3. (C) Analysis of Prox1 protein levels relative to β-actin by Western blot in LECs isolated at E16.5 and adult stages. Relative intensity of Prox1 staining normalized to β-actin is shown.