title: Cloned horse pregnancies produced using adult cumulus cells.
abstract: The objectives of the present study were to: (1) clone horses using adult cumulus cells; and (2) determine whether the cumulus cell donor affected the outcome. In vivo-matured cumulus-oocyte complexes were obtained using transvaginal ultrasound-guided follicle aspiration; oocytes were used as cytoplasts, whereas cumulus cells (from one of three different mares) were used as donor cells. Immediately following nuclear transfer and activation procedures, cloned embryos were transferred surgically to the oviduct of recipient mares (n = 2-5 embryos per recipient) that had ovulated within 24 h prior to the transfer. An initial pregnancy examination was performed between Days 14 and 16 (Day 0 = surgery); subsequent examinations were then performed every 7-10 days. A total of 136 follicles were aspirated in 96 mares, from which 72 oocytes were recovered (53%). Sixty-two cloned embryos were transferred to recipient mares, which resulted in seven (11.3%) ultrasonographically detectable conceptuses between Days 14 and 16. All seven conceptuses were lost spontaneously between Days 16 and 80. Cumulus cells from Mare 160 tended (P = 0.08) to result in a higher embryo survival rate than cumulus cells from Mare 221 (4/17 v. 1/25 respectively). To our knowledge, this is the first report documenting the establishment of cloned equine pregnancies derived from adult cumulus cells.
authors.affiliation: Northwest Equine Reproduction Laboratory, Department of Animal and Veterinary Science and Center for Reproductive Biology, University of Idaho, Moscow, ID 83844, USA. dirkv@uidaho.edu
authors.forename: Dirk K
authors.initials: DK
authors.lastname: Vanderwall
authors.forename: Gordon L
authors.initials: GL
authors.lastname: Woods
authors.forename: Kenneth I
authors.initials: KI
authors.lastname: Aston
authors.forename: Thomas D
authors.initials: TD
authors.lastname: Bunch
authors.forename: Guanpeng
authors.initials: G
authors.lastname: Li
authors.forename: Lora N
authors.initials: LN
authors.lastname: Meerdo
authors.forename: Kenneth L
authors.initials: KL
authors.lastname: White
mesh_terms: D000818:Animals; D002467:Cell Nucleus; D002478:Cells, Cultured; D016922:Cellular Senescence; D019976:Cloning, Organism; D020964:Embryo Loss; D004624:Embryo Transfer; D005260:Female; D006736:Horses; D053652:Nuclear Transfer Techniques; D009865:Oocytes; D006080:Ovarian Follicle / Q000166:cytology*; D011247:Pregnancy