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<0.05) lower in the iSCNT embryos than in the parthenogenetic control (95.7% and 64.4%, respectively). Although 21.5% of the bovine parthenogenetic embryos developed to the blastocyst stage, no iSCNT embryo developed beyond the 6-cell stage. In Experiment 2, the cleavage rate did not vary between the TSA (50 nM)-treated and non-treated whale iSCNT embryos (30.5 vs. 32.3%, respectively). Moreover, it did not vary between the TSA-treated iSCNT and SCNT embryos (30.5 vs. 32.0%, respectively). Only one TSA non-treated iSCNT embryo developed to a compacted morula with 20 nuclei. One TSA-treated whale SCNT embryo developed to the 8-cell stage, and out of five whale iSCNT embryos, a 6-cell stage embryo was positive for whale DNA. In conclusion, bovine oocytes have the ability to support development of sei whale nuclei up to the 6-cell stage.
Bhuiyan
Mohammad Musharraf Uddin
MM
Laboratory of Animal Reproduction, Obihiro University of Agriculture and Veterinary Medicine, Japan.
Suzuki
Yo
Y
Watanabe
Hiroyuki
H
Lee
Eunsong
E
Hirayama
Hiroki
H
Matsuoka
Koji
K
Fujise
Yoshihiro
Y
Ishikawa
Hajime
H
Ohsumi
Seiji
S
Fukui
Yutaka
Y
D000818:Animals; D050616:Balaenoptera / Q000196:embryology* / Q000254:growth & development; D001755:Blastocyst / Q000502:physiology; D002417:Cattle; D019976:Cloning, Organism / Q000379:methods*; D047108:Embryonic Development; D005260:Female; D006877:Hydroxamic Acids / Q000494:pharmacology; D009028:Morula / Q000502:physiology; D053652:Nuclear Transfer Techniques; D010053:Ovary / Q000196:embryology / Q000254:growth & development
D006877:Hydroxamic Acids; C012589:trichostatin A