Expression of bovine trophoblast interferon in conceptuses derived by in vitro techniques.
Expression of the trophoblast interferon, bovine trophoblast protein-1 (bTP-1), has been studied in embryos produced by in vitro maturation-in vitro fertilization (IVM-IVF). No bTP-1 production was noted until after embryos had reached the expanded blastocyst stage and had begun to hatch (Days 8-9 post-fertilization). Single blastocysts comprising 115 +/- 22 cells released 1.0 +/- 0.1 units of interferon activity/24 h. Amplification of conceptus mRNA by reverse transcription-polymerase chain reaction procedure with bTP-1-specific oligonucleotides confirmed that bTP-1 transcripts were present in blastocysts but were not detectable at earlier stages. Although cultured blastocysts produced by IVM-IVF procedures continued to secrete bTP-1 for a few days, they failed to attach to the substratum and form outgrowths, and soon lost structural integrity. However, when Day 8 blastocysts/morulae were transferred to the uteri of synchronized cows, recovered 4 days later, and placed into individual cultures, they attached and formed outgrowths that produced large amounts of bTP-1 (greater than 2000 units/culture/24 h after 14 days). Embryos thus first expressed bTP-1 when a functional trophectoderm was first formed, and induction did not require a period of in vivo development. However, continued viability of the blastocyst and bTP-1 production were not sustained in vitro and may require some exposure to the uterine environment.
Hernandez-Ledezma
J J
JJ
Department of Animal Sciences, University of Missouri, Columbia 65211.
Sikes
J D
JD
Murphy
C N
CN
Watson
A J
AJ
Schultz
G A
GA
Roberts
R M
RM
D000818:Animals; D001483:Base Sequence; D001755:Blastocyst / Q000378:metabolism; D002417:Cattle / Q000196:embryology* / Q000378:metabolism; D046508:Culture Techniques; D004624:Embryo Transfer; D005260:Female; D005307:Fertilization in Vitro; D015870:Gene Expression; D007370:Interferon Type I; D008969:Molecular Sequence Data; D009028:Morula / Q000378:metabolism; D016133:Polymerase Chain Reaction; D011247:Pregnancy; D011257:Pregnancy Proteins / Q000235:genetics* / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism
D007370:Interferon Type I; D011257:Pregnancy Proteins; D012333:RNA, Messenger; C020947:interferon tau