Parthenogenetic Activation of Oocytes

GV stage oocytes were injected with various peptidomimetics at 300 μM in a 50% aqueous solution (w/v) of dimethyl sulfoxide. Peptidomimetics were injected into oocyte by means of a Eppendorf Femto Jet (Eppendorf AG, Hamburg, Germany) and a Nikon Diaphot ECLIPSE TE300 inverted microscope (Nikon UK Ltd., Kingston upon Thames, Surrey, UK) equipped with a Narishige MM0-202N hydraulic three-dimensional micromanipulator (Narishige Inc., Sea Cliff, NY, USA) and subjected to in vitro maturation as described above. As a control, the BG34 reagent with threonine residues instead of phosphothreonine35 (link) was injected into oocytes at 300 μM. To test the oocytes for parthenogenetic activation, we collected mature MII oocytes and injected them with various reagents as described above for GV oocytes. Parthenogenetic activation was accomplished by incubating the MII oocytes in the calcium-free CZB medium51 (link) supplemented with 5 mM SrCl₂ at 5% CO₂ (v/v, in humidified air) and 37 °C for 2 hr52 (link).