title: Effect of individual heifer oocyte donors on cloned embryo development in vitro.
abstract: The aim of this study was to determine the effect of individual oocyte donors on cloned embryo development in vitro. Five Holstein heifers of varied genetic origins were subject to ovum pick up (OPU) once weekly. In total, 913 oocytes were recovered from 1304 follicles. A mean of 7.7+/-0.4 oocytes was recovered per session per animal. Individual mean oocyte production varied significantly in quantity but not in quality (morphological categories) among heifers. Oocytes from individual heifers were used as recipient cytoplasm for somatic cell nuclear transfer (SCNT). Cumulus cells, collected from a single Holstein cow genetically unrelated to the oocyte donor, were used as donor cells. Although the percentage of reconstructed embryos that started to cleave was nearly constant, the percentage of cleaved embryos that developed into blastocysts showed clear individual heifer variation (61%, 51%, 31%, 28% and 24%, respectively), with a mean of 38% showing blastocyst formation. In vitro fertilization (IVF) was also conducted with oocyte from the same heifers used in SCNT. A variation of blastocyst production among individual heifers was also shown in the IVF experiment, but the rank of oocyte donor based on the blastocyst rate was changed. In conclusion, individual oocyte donor may have an effect on cloned embryo development in vitro, which differed from the effect on IVF embryos.
authors.affiliation: Shanghai Institute of Medical Genetics, Shanghai Children's Hospital, Shanghai Jiao Tong University, School of Medicine, Shanghai 20040, China.
authors.forename: Xiao-Yu
authors.initials: XY
authors.lastname: Yang
authors.forename: Jian-Guo
authors.initials: JG
authors.lastname: Zhao
authors.forename: Hua
authors.initials: H
authors.lastname: Li
authors.forename: Hai-Feng
authors.initials: HF
authors.lastname: Liu
authors.forename: Ying
authors.initials: Y
authors.lastname: Huang
authors.forename: Shu-Zhen
authors.initials: SZ
authors.lastname: Huang
authors.forename: Fanyi
authors.initials: F
authors.lastname: Zeng
authors.forename: Yi-Tao
authors.initials: YT
authors.lastname: Zeng
mesh_terms: D000818:Animals; D002417:Cattle / Q000502:physiology*; D019976:Cloning, Organism / Q000662:veterinary*; D046149:Embryo Culture Techniques / Q000662:veterinary*; D004624:Embryo Transfer / Q000662:veterinary; D005260:Female; D005307:Fertilization in Vitro / Q000662:veterinary; D053652:Nuclear Transfer Techniques / Q000662:veterinary; D018587:Oocyte Donation / Q000662:veterinary*; D009865:Oocytes / Q000502:physiology*; D011247:Pregnancy