Superovulation, fertilization and parthenogenetic activation
For superovulation, 6-week-old female mice were injected with 5 IU of
pregnant mare serum gonadotropin (PMSG). After 48 h, mice were injected
with 5 IU of human chorionic gonadotropin (hCG).
For fertilization, superovulated female mice were mated with adult
males. Successful mating was confirmed by observation of vaginal plugs
the next morning and recorded as E0.5. Embryos were harvested from
ampullae of oviducts at the indicated times according to experimental
need.
For parthenogenetic activation, oocytes at the MII stage were collected
and treated with 5μM calcium ionophore A23187 (C7522; Sigma-Aldrich) for
5 min, then cultured in M2 medium containing10μM cycloheximide (01810;
Sigma-Aldrich).