We investigated the microtubule dynamics, including the inheritance of donor centrosomes and the mitotic spindle assembly occurring during the first mitosis of somatic cell nuclear transfer (SCNT) embryos in pigs. SCNT embryos were fixed 15 min and 1 h after fusion in order to assess the inheritance pattern of the donor centrosome. The distribution and dynamic of the centrosome and microtubule during the first mitotic phase of SCNT embryos were also evaluated. The frequency of embryos evidencing γ‐gtubulin spots (centrosome) was 93.2% in the SCNT embryos 15 min after fusion. In the majority of the SCNT embryos (61.5%), however, no centrosome was observed 1 h after fusion. The frequency of the embryos with no or abnormal mitotic spindles 20 h after fusion was 19.6%. The γ‐gtubulin spots were detected near the nuclei of somatic cells regardless of cell cycle phase, whereas γ‐g tubulin spots in the SCNT embryos were observed only during the inter‐ganaphase transition. These results showed that the donor centrosome is inherited into the SCNT embryos, but failed to assemble the normal mitotic spindles during first mitotic phase in some SCNT embryos.

ABSTRACT   INTRODUCTION   MATERIALS AND METHODS   RESULTS   DISCUSSION   ACKNOWLEDGEMENTS   REFERENCES

• Dae-Jin Kwon(College of Veterinary Medicine and Institute of Veterinary Science) | 권대진
• Choon-Keun Park(College of Animal Life Sciences, Kangwon National University, Chuncheon 200-701, Korea)
• Boo-Keun Yang(College of Animal Life Sciences, Kangwon National University, Chuncheon 200-701, Korea)
• Hee-Tae Cheong(College of Veterinary Medicine and Institute of Veterinary Science)