title: No transuterine migration of fertilised ova after unilateral embryo transfer in mice.
abstract: Transuterine migration is the passage of fertilised ova from one uterine horn into the other. The phenomenon has been described for animals of different species with a bicornuate type of uterus. Whether or not it occurs in rodents is questionable, but could have an impact on the way embryo transfers are carried out, i.e. unilaterally or bilaterally. The aim of this study was to examine the occurrence of transuterine migrations in nulliparous and multiparous mice after unilateral embryo transfer. Sixteen two-cell embryos were transferred into either the left or the right oviduct of mice with different genetic origin. With the exception of one reabsorption site in the opposite uterine horn, we never found evidence for the occurrence of transuterine migration. This is also true for embryo transfers carried out after parturition of the surrogate mother. Even the successful development of up to 13 embryos in one uterine horn did not result in transmigration but may be the reason for the widespread assumption that transuterine migration occurs after unilateral embryo transfers. The separation of the uterine body and the prevaginal portion of the uterine cervix into two canals by a septum seems to be the main reason for the absence of successful transuterine migration in mice.
authors.affiliation: Institute of Laboratory Animal Science and Research Center Biomodels Austria, University of Veterinary Medicine Vienna, 1210 Vienna, Austria. thomas.ruelicke@vu-wien.ac.at
authors.forename: Thomas
authors.initials: T
authors.lastname: Rülicke
authors.forename: Amy
authors.initials: A
authors.lastname: Haenggli
authors.forename: Kirsten
authors.initials: K
authors.lastname: Rappold
authors.forename: Ueli
authors.initials: U
authors.lastname: Moehrlen
authors.forename: Thomas
authors.initials: T
authors.lastname: Stallmach
mesh_terms: D000818:Animals; D004624:Embryo Transfer / Q000662:veterinary*; D005260:Female; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D013533:Gestational Carriers; D014599:Uterus / Q000502:physiology* / Q000648:ultrastructure; D015053:Zygote / Q000502:physiology*