title: Influence of the uterine environment on the development of in vitro-produced equine embryos.
abstract: The necessity for early interaction between the embryo and the oviductal and/or uterine environment in the horse is reflected by several striking differences between equine embryos that develop in vivo and those produced in vitro. Better understanding of the salient interactions may help to improve the efficiency of in vitro equine embryo production. In an initial experiment, cleavage-stage in vitro-produced (IVP) equine embryos were transferred into the uterus of recipient mares that had ovulated recently to determine whether premature placement in this in vivo environment would improve subsequent development. In a second experiment, an important element of the uterine environment was mimicked by adding uterocalin, a major component of the endometrial secretions during early pregnancy, to the culture medium. Intrauterine transfer of cleavage-stage IVP equine embryos yielded neither ultrasonographically detectable pregnancies nor day 7 blastocysts, indicating that the uterus is not a suitable environment for pre-compact morula stage horse embryos. By contrast, exposure to uterocalin during IVP improved capsule formation, although it did not measurably affect the development or expression of a panel of genes known to differ between in vivo and in vitro embryos. Further studies are required to evaluate whether uterocalin serves purely as a carrier protein or more directly promotes improved capsule development.
authors.affiliation: Department of Reproduction, Obstetrics and Herd Health, Ghent University, Salisburylaan, Merelbeke, Belgium. katrien.smits@ugent.be
authors.forename: Katrien
authors.initials: K
authors.lastname: Smits
authors.forename: Jan
authors.initials: J
authors.lastname: Govaere
authors.forename: Luc J
authors.initials: LJ
authors.lastname: Peelman
authors.forename: Karen
authors.initials: K
authors.lastname: Goossens
authors.forename: Dirk C
authors.initials: DC
authors.lastname: de Graaf
authors.forename: Dries
authors.initials: D
authors.lastname: Vercauteren
authors.forename: Leen
authors.initials: L
authors.lastname: Vandaele
authors.forename: Maarten
authors.initials: M
authors.lastname: Hoogewijs
authors.forename: Eline
authors.initials: E
authors.lastname: Wydooghe
authors.forename: Tom
authors.initials: T
authors.lastname: Stout
authors.forename: Ann
authors.initials: A
authors.lastname: Van Soom
mesh_terms: D000818:Animals; D002478:Cells, Cultured; D060833:Cellular Microenvironment / Q000502:physiology; D002970:Cleavage Stage, Ovum / Q000166:cytology / Q000502:physiology; D046149:Embryo Culture Techniques / Q000379:methods; D004624:Embryo Transfer / Q000662:veterinary; D004622:Embryo, Mammalian / Q000166:cytology* / Q000502:physiology; D047108:Embryonic Development / Q000502:physiology; D005260:Female; D005307:Fertilization in Vitro / Q000662:veterinary; D006736:Horses / Q000196:embryology* / Q000502:physiology; D054834:Lipocalins / Q000494:pharmacology; D011247:Pregnancy; D011994:Recombinant Proteins / Q000494:pharmacology; D014599:Uterus / Q000502:physiology*
chemical_list: D054834:Lipocalins; D011994:Recombinant Proteins