title: Synthesis of early pregnancy factor using red deer (Cervus elaphus) as a delayed implantation model.
abstract: OBJECTIVE
  This study measured serum early pregnancy factor (EPF) in pregnant red deer (Cervus elaphus) and ascertained whether EPF synthesis is associated with implantation.
  
  
  METHODS
  Serial serum samples were taken from mated hinds up to 42 days postconception and analyzed for EPF activity using the rosette inhibition test. EPF activity was then correlated with calving records and stages of preimplantation development.
  
  
  RESULTS
  EPF was detected in all pregnant animals, with a twin pregnancy giving increased EPF activity. Three animals gave an EPF response following fertilization but failed to continue beyond the preimplantation embryo stage. The increase in EPF synthesis previously associated with implantation in other mammals occurred at the blastocyst stage in red deer.
  
  
  CONCLUSIONS
  EPF synthesis in red deer (Cervus elaphus) is consistent with the preimplantation period, as occurs in other mammals. However, the second phase of the biphasic increase in early pregnancy factor production is associated with blastocyst formation, not implantation.
authors.affiliation: Department of Biochemistry, University of Otago, Dunedin, New Zealand.
authors.forename: G E
authors.initials: GE
authors.lastname: Lash
authors.forename: M
authors.initials: M
authors.lastname: Legge
authors.forename: M
authors.initials: M
authors.lastname: Fisher
mesh_terms: D000818:Animals; D018835:Chaperonin 10; D003670:Deer / Q000502:physiology*; D010065:Embryo Implantation, Delayed / Q000502:physiology*; D005260:Female; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D010452:Peptide Biosynthesis; D010455:Peptides / Q000097:blood; D011247:Pregnancy; D011257:Pregnancy Proteins; D011272:Pregnancy, Multiple / Q000378:metabolism; D013491:Suppressor Factors, Immunologic
chemical_list: D018835:Chaperonin 10; D010455:Peptides; D011257:Pregnancy Proteins; D013491:Suppressor Factors, Immunologic; C025124:early pregnancy factor