Human leukemia inhibitory factor improves the viability of cultured ovine embryos.
Embryos were collected from ewes on Day 6 after estrus (Day 0 = estrus), placed in M2 culture medium, and assigned to 1 of 4 treatment groups. Some embryos were transferred to recipient ewes on Day 6 of their estrous cycle either in pairs (group 1) or singularly (group 2) within 3 h of collection. The remaining embryos were individually cultured for 48 h in an atmosphere of 5% CO2 in humidified air in either synthetic oviduct fluid (SOF) medium (group 3) or SOF containing 1,000 U/ml of recombinant human leukemia inhibitory factor (hLIF) (SOF + hLIF: group 4). These embryos were then transferred to recipient ewes on Day 8 of their estrous cycle. The addition of hLIF to culture medium significantly improved the development of the embryos compared with control embryos prior to transfer (blastocysts hatching from the zona pellucida: group 3 = 16% vs. group 4 = 64%, p less than 0.05; those degenerative: group 3 = 27% vs. group 4 = 9%, p less than 0.05) and the subsequent pregnancy rates of the recipient ewes, receiving a single embryo, at Day 70 of pregnancy (group 3 = 16% vs. group 4 = 50%, p less than 0.05). The pregnancy rate of ewes given embryos cultured for 48 h in SOF + hLIF prior to transfer (50%; group 4) was similar to the group 2 ewes receiving a single embryo soon after collection (52%), but the pregnancy rate for both groups was significantly lower than that for the group 1 ewes receiving two embryos soon after collection (89%: 53% twins, 36% singles; p less than 0.05).
Fry
R C
RC
Victorian Institute of Animal Science, Werribee, Australia.
Batt
P A
PA
Fairclough
R J
RJ
Parr
R A
RA
D000818:Animals; D046508:Culture Techniques; D004624:Embryo Transfer; D005260:Female; D005328:Fetal Viability; D006131:Growth Inhibitors / Q000494:pharmacology*; D006801:Humans; D015850:Interleukin-6; D053605:Leukemia Inhibitory Factor; D008222:Lymphokines / Q000494:pharmacology*; D011247:Pregnancy; D011994:Recombinant Proteins / Q000494:pharmacology; D012756:Sheep / Q000196:embryology*
D006131:Growth Inhibitors; D015850:Interleukin-6; C507837:LIF protein, human; D053605:Leukemia Inhibitory Factor; D008222:Lymphokines; D011994:Recombinant Proteins