Availability of empty zona pellucida for generating embryonic chimeras.
In the present study we used an empty zona pellucida derived from hatched blastocysts as an alternative source for embryo aggregation and compared results with the conventional microwell method. Denuded 4-cell stage porcine embryos were aggregated by introduction into an empty zona or placement within a concave microwell. The present study showed that although the rate of aggregate formation was similar, the blastocyst rates and allocation of more cells to the inner cell mass (ICM) in the resultant aggregates were increased significantly more in the empty zona than in the microwell. Notably, using an empty zona showed no limitations with regards to the increased number of embryos aggregated or embryonic stages for aggregation, while partial or no aggregation frequently occurred in the microwell. The discrepancy may be due to the difference of microenvironments where the embryos were placed namely, the presence/absence of zona pellucida. We hypothesize the success of the empty zona in generating aggregates is due to the physical aggregation of individual embryos allowing closer contact between the blastomeres and/or embryos compared with a concave microwell. These results indicate that aggregation conditions could influence overall production efficiency and developmental potential of aggregates, suggesting physical restraint via empty zona that provide three-dimensional pressures is an important factor for successful embryo aggregation.
Institute of Green Bio Science and Technology, Seoul National University, Pyeong Chang, Kangwon do, Korea.
Chi-Hun
CH
Park
College of Agriculture and Life Science, Chonnam National University, Gwangju, Korea.
Young-Hee
YH
Jeong
Department of Agricultural Biotechnology, Animal Biotechnology Major, and Research Institute of Agriculture and Life Science, Seoul National University, Seoul, Korea.
Dong-Kyung
DK
Lee
Department of Agricultural Biotechnology, Animal Biotechnology Major, and Research Institute of Agriculture and Life Science, Seoul National University, Seoul, Korea.
Jae Yeon
JY
Hwang
Institute of Green Bio Science and Technology, Seoul National University, Pyeong Chang, Kangwon do, Korea.
Kyung-Jun
KJ
Uh
Institute of Green Bio Science and Technology, Seoul National University, Pyeong Chang, Kangwon do, Korea; International Agriculture Technology Graduate School, Seoul National University, Pyeong Chang, Kangwon do, Korea.
Su-Cheong
SC
Yeom
Institute of Green Bio Science and Technology, Seoul National University, Pyeong Chang, Kangwon do, Korea; Division of Nephrology, Seoul National University College of Medicine, Seoul, Korea.
Curie
C
Ahn
Institute of Green Bio Science and Technology, Seoul National University, Pyeong Chang, Kangwon do, Korea; Department of Agricultural Biotechnology, Animal Biotechnology Major, and Research Institute of Agriculture and Life Science, Seoul National University, Seoul, Korea.
Chang-Kyu
CK
Lee
D000818:Animals; D001755:Blastocyst / Q000166:cytology*; D002678:Chimera; D046149:Embryo Culture Techniques / Q000379:methods*; D047108:Embryonic Development; D005260:Female; D013552:Swine / Q000033:anatomy & histology / Q000196:embryology*; D015044:Zona Pellucida / Q000502:physiology*