Development of Enucleated Mouse Oocytes Receiving PDGF or FGF Treated Germ Cells after Activation with Electrical Stimulation

Abstract

To improve the developmental ability of enucleated mouse oocytes that received male fetal germ cells at 15.5 days post coitum (G₀ stage), the effects of parthenogenetic activation with electrical stimulation and pretreatment of germ cells with PDGF or FGF, competent factors for quiescent cells, were examined. Preliminary evaluations revealed that the best conditions for electrical activation of unfertilized eggs were 100 μsec direct current pulses at 150 V/mm followed by 2 pulses of 50 V/mm at 20 min intervals (100% for activation and 94% for development to blastocysts). Fusion rates were the same for PDGF, FGF and control groups (35 to 46%). The activation rate in the PDGF group was significantly higher (90%) than that of controls (78%). The proportion of activated eggs that developed to morulae and blastocysts was high in the PDGF group but was not significantly different from that in controls (82 vs 68%). One live fetus with 32 somites was obtained on day 10.5 of pregnancy after the transfer of eggs reconstituted with PDGF treated germ cells. Repeated electrical parthenogenetic stimulation and pretreatment of fetal germ cells with PDGF appeared to enhance the development of reconstituted eggs.