title: Differential development of rabbit embryos derived from parthenogenesis and nuclear transfer.
abstract: Parthenogenetic development (PA) is often used as a model to investigate activation protocols for nuclear transfer (NT) embryos. The objective of this study was to compare the development, as well as the dynamics of the nuclear materials and microtubules of PA and NT embryos following similar activation treatment. Our results demonstrate that, during parthenogenesis, activation through either electrical pulses or chemical stimulation alone resulted in low cleavage rates and compromised development. A combination of two sets of electrical pulses and a 2-h-exposure to chemical activation medium (5 microg/ml cycloheximide (CHX) and 2 mM 6-dimethylaminopurine (6-DMAP) in KSOM+0.1% BSA) could effectively activate rabbit oocytes, and resulted in a 99% (n = 73) cleavage rate with greater than 60% (n = 73) developing to blastocysts at day 4. However, the same activation protocol following NT resulted in only 65-72% of oocytes cleaved (depending on donor cell type), with less than 20% developing to the blastocyst stage. The differences observed between NT and PA embryos subjected to the same activation protocol were also evident in terms of the time required for their development to the blastocyst stage, as well as the cell numbers present in blastocysts at day 6. Furthermore, laser confocal microscopy revealed that pronuclear formation in the NT embryos was delayed by comparison to that in the parthenotes. In conclusion, our study suggests that an effective protocol for parthenogenesis cannot promise a comparable outcome for NT embryos.
authors.affiliation: Department of Animal Science and Center for Regenerative Biology, University of Connecticut, Storrs, Connecticut 06269-4243, USA.
authors.forename: Ji-Long
authors.initials: JL
authors.lastname: Liu
authors.forename: Li-Ying
authors.initials: LY
authors.lastname: Sung
authors.forename: Fuliang
authors.initials: F
authors.lastname: Du
authors.forename: Marina
authors.initials: M
authors.lastname: Julian
authors.forename: Shie
authors.initials: S
authors.lastname: Jiang
authors.forename: Michele
authors.initials: M
authors.lastname: Barber
authors.forename: Jie
authors.initials: J
authors.lastname: Xu
authors.forename: X Cindy
authors.initials: XC
authors.lastname: Tian
authors.forename: Xiangzhong
authors.initials: X
authors.lastname: Yang
mesh_terms: D000818:Animals; D002467:Cell Nucleus / Q000235:genetics* / Q000378:metabolism; D003470:Culture Media; D046508:Culture Techniques; D004558:Electric Stimulation; D004622:Embryo, Mammalian / Q000166:cytology* / Q000196:embryology*; D005260:Female; D008870:Microtubules / Q000378:metabolism; D009865:Oocytes / Q000166:cytology / Q000187:drug effects / Q000254:growth & development / Q000378:metabolism; D010312:Parthenogenesis; D011817:Rabbits; D013997:Time Factors
chemical_list: D003470:Culture Media