title: Efficient production of transgenic cloned calves using preimplantation screening.
abstract: The genetic manipulation of donor cells before nuclear transfer (NT) enables prior selection for transgene integration. However, selection for genetically modified cells using antibiotic drugs often results in mixed populations, resulting in a mixture of transgenic and nontransgenic donor cells for NT. In this study, we attempted to develop efficient strategies for the generation of human bile salt-stimulated lipase (BSSL) transgenic cows. Preimplantation screening by either biopsy or green fluorescent protein (GFP) expression was used to detect NT-derived BSSL transgenic embryos to ensure that the calf born would be transgenic. We compared the development rates of NT-derived embryos from G418- and GFP-selected donor cells. There were no significant differences (P < 0.001) in cleavage rate (67.2% vs. 60.0%) and blastocyst formation rate (44.9% vs. 41.2%). We also compared the pregnancy rates of the G418/biopsy and GFP preimplantation screened NT-derived blastocysts. The Day 40 pregnancy rate of the G418/biopsy group (40%) was lower than that of the GFP group (57%), but the calf birth rate of the G418/biopsy group (40%) was higher than that of the GFP group (21%). Healthy BSSL transgenic calves were born after both screening processes. This is the first report of biopsy-screened cloned transgenic animals. The results suggest that both selection methods are useful for detecting transgenic NT embryos without negatively affecting their development into viable transgenic offspring.
authors.affiliation: PPL Therapeutics Inc., Blacksburg, Virginia 24060, USA. schen@ppl-therapeutics.com
authors.forename: Shu-Hung
authors.initials: SH
authors.lastname: Chen
authors.forename: Todd D
authors.initials: TD
authors.lastname: Vaught
authors.forename: Jeff A
authors.initials: JA
authors.lastname: Monahan
authors.forename: Jeremy
authors.initials: J
authors.lastname: Boone
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Emslie
authors.forename: Peter M
authors.initials: PM
authors.lastname: Jobst
authors.forename: Ashley E
authors.initials: AE
authors.lastname: Lamborn
authors.forename: Angelika
authors.initials: A
authors.lastname: Schnieke
authors.forename: Laura
authors.initials: L
authors.lastname: Robertson
authors.forename: Alan
authors.initials: A
authors.lastname: Colman
authors.forename: Yifan
authors.initials: Y
authors.lastname: Dai
authors.forename: Irina A
authors.initials: IA
authors.lastname: Polejaeva
authors.forename: David L
authors.initials: DL
authors.lastname: Ayares
mesh_terms: D000818:Animals; D030801:Animals, Genetically Modified; D000831:Animals, Newborn; D001706:Biopsy; D001755:Blastocyst / Q000502:physiology*; D002417:Cattle; D005260:Female; D018628:Gene Dosage; D017930:Genes, Reporter; D005820:Genetic Testing / Q000379:methods*; D049452:Green Fluorescent Proteins; D008164:Luminescent Proteins / Q000235:genetics; D008297:Male; D011247:Pregnancy; D011256:Pregnancy Outcome; D011270:Pregnancy, Animal; D027724:Reproductive Techniques, Assisted; D002787:Sterol Esterase / Q000096:biosynthesis / Q000235:genetics*; D019076:Transgenes
chemical_list: D008164:Luminescent Proteins; D049452:Green Fluorescent Proteins; C054784:bile salt-stimulated lipase; D002787:Sterol Esterase