139 TRICHOSTATIN A IMPROVED IN VITRO DEVELOPMENT OF PORCINE NUCLEAR TRANSFER EMBRYOS PRODUCED BY A NEW ACTIVATION METHOD

Abstract

Recently, it has been reported that a new activation method, brief exposure to cycloheximide before electrical activation, could increase development rates and reduce cell death. In our study, we allocated reconstructed SCNT embryos into 3 groups: electrical activation followed by exposure to cycloheximide (10 μg mL^–1) for 4 h (ELE+CHX); exposure to cycloheximide (10 μg mL^–1) for 10 min followed by electrical activation (CHX+ELE); and electrical pulse treatment alone (ELE). We found the CHX+ELE (10 min) group had a similar blastocyst formation rate and total blastocyst number with the ELE+CHX (4 h) group, and both groups could increase in vitro development compared with the ELE group. Trichostatin A (TSA), an inhibitor of histone deacetylase, has been reported to potentially enhance cloning efficiency. We examine the effect of TSA on nuclear transfer embryos produced by the CHX+ELE activation method. The reconstructed embryos were treated with 50 nM TSA for 0 and 36 h. We found that 50 nM TSA for 36 h after activation had an increased blastocyst rate compared with the control (15.35 v. 8.84%; P < 0.05), but there was no difference in cleavage rate or in total blastocyst numbers. Our data demonstrate that TSA treatment could significantly improve pig nuclear transfer embryos produced by a new activation method.