Mir9-3^tm1Sia

A 90 nt region encoding the mature microRNA was replaced with a floxed pgk-neo cassette via homologous recombination. Quantitative RT-PCR analysis confirmed the absence of RNA expression and lack of any compensatory increase in Mir9-1 expression in homozygous mice null for both Mir9-2 and Mir9-3. (J:170671)