title: Production of interferon by red deer (Cervus elaphus) conceptuses and the effects of roIFN-tau on the timing of luteolysis and the success of asynchronous embryo transfer.
abstract: The role of interferon in early pregnancy in red deer was investigated by (a) measuring production of interferon by the conceptus, (b) testing the anti-luteolytic effect of recombinant interferon-tau in non-pregnant hinds, and (c) treatment of hinds with interferon after asynchronous embryo transfer. Blastocysts were collected from 34 hinds by uterine flushing 14 (n = 2), 16 (n = 2), 18 (n = 8), 20 (n = 13) or 22 (n = 9) days after synchronization of oestrus with progesterone withdrawal. Interferon anti-viral activity was detectable in uterine flushings from day 16 to day 22, and increased with duration of gestation (P < 0.01) and developmental stage (P < 0.01). When interferon-tau was administered daily between day 14 and day 20 to non-pregnant hinds to mimic natural blastocyst production, luteolysis was delayed by a dose of 0.2 mg day(-1) (27.3 +/- 1.3 days after synchronization, n = 4 versus 21 +/- 0 days in control hinds, n = 3; P < 0.05). Interferon-tau was administered to hinds after asynchronous embryo transfer to determine whether it protects the conceptus against early pregnancy loss. Embryos (n = 24) collected on day 6 from naturally mated, superovulated donors (n = 15) were transferred into synchronized recipients on day 10 or day 11. Interferon-tau treatment (0.2 mg daily from day 14 to 20) increased calving rate from 0 to 64% in all recipients (0/11 versus 7/11, P < 0.005), and from 0 to 67% in day 10 recipients (0/8 versus 6/9, P < 0.01). The increased success rate of asynchronous embryo transfer after interferon-tau treatment in cervids may be of benefit where mismatched embryo-maternal signalling leads to failure in the establishment of pregnancy.
authors.affiliation: Division of Animal Physiology, School of Biological Sciences, University of Nottingham, Sutton Bonington Campus, Loughborough LE12 5RD, UK.
authors.forename: K J
authors.initials: KJ
authors.lastname: Demmers
authors.forename: H N
authors.initials: HN
authors.lastname: Jabbour
authors.forename: D W
authors.initials: DW
authors.lastname: Deakin
authors.forename: A P
authors.initials: AP
authors.lastname: Flint
mesh_terms: D000818:Animals; D001947:Breeding; D003338:Corpus Luteum / Q000187:drug effects; D003670:Deer / Q000196:embryology*; D004624:Embryo Transfer / Q000379:methods / Q000662:veterinary*; D004622:Embryo, Mammalian / Q000378:metabolism*; D005260:Female; D007370:Interferon Type I / Q000378:metabolism* / Q000494:pharmacology*; D008183:Luteal Phase / Q000187:drug effects; D011247:Pregnancy; D011374:Progesterone / Q000097:blood; D011994:Recombinant Proteins
chemical_list: D007370:Interferon Type I; D011994:Recombinant Proteins; D011374:Progesterone