Production of Sei Whale (Balaenoptera borealis) Cloned Embryos by Inter- and Intra-Species Somatic Cell Nuclear Transfer

The objectives of this study were to choose an effective embryo reconstruction method and an effective post-activation agent for in vitro production of sei whale (Balaenoptera borealis) interspecies somatic cell nuclear transfer (iSCNT) embryos. Moreover, trichostatin A (TSA) treatment of whale iSCNT embryos was performed to improve the in vitro embryo development. In Experiment 1, the fusion rate was significantly higher (88.1%) in embryos reconstructed using the intracytoplasmic cell injection method (ICI) than that (48.7%) in the subzonal cell insertion (SUZI) counterpart. The rates of pseudopronucleus (PPN) formation (77.4 vs. 77.2%) and cleavage (24.5 vs. 37.0%) did not vary between ICI and SUZI. However, the PPN formation and cleavage rates were significantly (P