Production of cloned cattle from in vitro systems.
The pregnancy initiation and maintenance rates of nuclear transfer embryos produced from several bovine cell types were measured to determine which cell types produced healthy calves and had growth characteristics that would allow for genetic manipulation. Considerable variability between cell types from one animal and the same cell type from different animals was observed. In general, cultured fetal cells performed better with respect to pregnancy initiation and calving than adult cells with the exception of cumulous cells, which produced the highest overall pregnancy and calving rates. The cell type that combined relatively high pregnancy initiation and calving rates with growth characteristics that allowed for extended proliferation in culture were fetal genital ridge (GR) cells. Cultured GR cells used in nuclear transfer and embryo transfer initiated pregnancies in 40% of recipient heifers (197), and of all recipients that received nuclear transfer embryos, 9% produced live calves. Cultured GR cells doubled as many as 85 times overall and up to 75 times after dilution to single-cell culture. A comparison between transfected and nontransfected cells showed that transfected cells had lower pregnancy initiation (22% versus 32%) and calving (3.4% versus 8.9%) rates.
Forsberg
Erik J
EJ
Infigen, Inc., 1825 Infinity Drive, DeForest, WI 53532, USA.
Strelchenko
Nikolai S
NS
Augenstein
Monica L
ML
Betthauser
Jeffery M
JM
Childs
Lynette A
LA
Eilertsen
Kenneth J
KJ
Enos
Joellyn M
JM
Forsythe
Todd M
TM
Golueke
Paul J
PJ
Koppang
Richard W
RW
Lange
Gail
G
Lesmeister
Tiffany L
TL
Mallon
Kelly S
KS
Mell
Greg D
GD
Misica
Pavla M
PM
Pace
Marvin M
MM
Pfister-Genskow
Martha
M
Voelker
Gary R
GR
Watt
Steven R
SR
Bishop
Michael D
MD
D000818:Animals; D000831:Animals, Newborn; D002417:Cattle; D002455:Cell Division / Q000502:physiology; D002469:Cell Separation; D002478:Cells, Cultured; D019976:Cloning, Organism / Q000379:methods*; D004431:Ear, External / Q000166:cytology / Q000196:embryology; D004624:Embryo Transfer; D005260:Female; D005307:Fertilization in Vitro; D005333:Fetus / Q000166:cytology / Q000502:physiology; D005835:Genitalia / Q000196:embryology; D018895:Microsatellite Repeats; D053652:Nuclear Transfer Techniques; D009924:Organ Culture Techniques; D011247:Pregnancy; D011270:Pregnancy, Animal / Q000502:physiology*; D014162:Transfection