Polyploidy is occurred by the process of endomitosis or cell fusion and usually represent terminally differentiated stage. Their effects on the developmental process were mainly investigated in the amphibian and fishes, and only observed in some rodents as mammalian model. Recently, we have established tetraploidy somatic cell nuclear transfer-derived human embryonic stem cells (SCNT-hESCs) and examined whether it could be available as a research model for the polyploidy cells existed in the human tissues. Two tetraploid hESC lines were artificially acquired by reintroduction of remained 1st polar body during the establishment of SCNT-hESC using MII oocytes obtained from female donors and dermal fibroblasts (DFB) from a 35-year-old adult male. These tetraploid SCNT-hESC lines (CHA-NT1 and CHA-NT3) were identified by the cytogenetic genotyping (91, XXXY,-6, t[2:6] / 92,XXXY,-12,+20) and have shown of indefinite proliferation, but slow speed when compared to euploid SCNT-hESCs. Using the eight Short Tendem Repeat (STR) markers, it was confirmed that both CHA-NT1 and CHA-NT3 lines contain both nuclear and oocyte donor genotypes. These hESCs expressed pluripotency markers and their embryoid bodies (EB) also expressed markers of the three embryonic germ layers and formed teratoma after transplantation into immune deficient mice. This study showed that tetraploidy does not affect the activities of proliferation and differentiation in SCNT-hESC. Therefore, tetraploid hESC lines established after SCNT procedure could be differentiated into various types of cells and could be an useful model for the study of the polyploidy cells in the tissues.

ABSTRACT
  INTRODUCTION
  MATERIALS AND METHODS
  RESULTS
  DISCUSSIONS
  REFERENCES

• Dong-Hyuk Shin(Fertility Center of CHA Gangnam Medical Center, College of Medicine, CHA University, Dept. of Animal Biotechnology, Konkuk University)
• Jeoung-Eun Lee(CHA Stem Cell Institute, CHA University)
• Jin Hee Eum(Fertility Center of CHA Gangnam Medical Center, College of Medicine, CHA University)
• Young Gie Chung(CHA Stem Cell Institute, CHA University)
• Hoon Taek Lee(Dept. of Animal Biotechnology, Konkuk University) Corresponding Author
• Dong Ryul Lee(CHA Stem Cell Institute, CHA University, Dept. of Biomedical Science, College of Life Science, CHA University) Corresponding Author