In utero Electroporation of Fmr1 Mice

Timed pregnant female C57BL/6 Fmr1 HET mice were in utero electroporated as described previously (Fig. 1a; Suresh and Dunaevsky, 2017 (link)). Briefly, embryonic day (E)15.5 timed pregnant C57BL/6 Fmr1 HET mice were injected with Buprenorphine (0.1 mg/kg) 30 min before the surgery. Following this, the dams were anaesthetized using an isoflurane-oxygen mixture (induction: 5% isoflurane/2 l/min O₂, maintenance: 2% isoflurane/2 l/min O₂). A small incision was made within the abdominal walls and uterine horns were exposed. 0.5 μl of a 4 μg/μl DNA solution of pCAG-tdTomato and pUB-SEP-GluA2-WPRE was injected into the cerebral lateral ventricles of E15.5 mouse embryo using a pulled glass pipette (BF100-94 Sutter Instrument) and Parker Picospritzer III microinjection system. The head was then placed between 3-mm tweezer electrodes so as to target the motor cortex. Electroporation was achieved using five square pulses (5 ms long at 1 Hz, 35 mV) using BTX Harvard Electro Square Porator ECM 830. Embryos were returned back into the abdominal cavity, and the abdominal muscles were sutured using non absorbable sutures (Ethicon Permahand). The dams were revived and monitored for distress over a period of 24 h after surgery. Dams were allowed to deliver naturally.