In utero Electroporation of miRNA and Fmr1 in Mice

As previously described^{23 (link)}, miRNA or Fmr1 overexpression constructs or Fmr1 shRNA constructs were electroporated in utero into timed pregnant CD-1 mice. Briefly, E12.5 or E14.5 pregnant dams were anaesthetised using pentobarbital sodium, and the uterine horns were exposed. Two to 3 μg/μl of plasmids or 40 µM miRNA antagomirs spiked with Fast Green (Sigma, Louis, Missouri, USA) were injected into the lateral ventricle of the embryo brain. Electroporation was conducted with electric pulses of 20–30 V for 50 ms, which were repeated five times with 950-ms intervals using the BTX-ECM830 electroporator (Harvard Apparatus, Holliston, Massachusetts, USA).