title: Investigation of effects of pregnant mare serum gonadotropin (PMSG) on the chromosomal complement of CD-1 mouse embryos.
abstract: OBJECTIVE
  The objective of this study was to examine the effect of superovulatory doses of gonadotropins on the frequency of chromosomal abnormalities of mouse embryos.
  
  
  METHODS
  Chromosome analysis of 8- to 16-cell stage mouse embryos and zygotes was performed by a cytogenetic method.
  
  
  RESULTS
  There was no significant effect of the pregnant mare serum gonadotropin (PMSG) dose on the level of aneuploidy and structural abnormalities from 8- to 16-cell-stage embryos among superovulated groups. However, a simple dose-response relationship between the PMSG dose and the incidence of polyploidy was observed, with the level of polyploidy rising from 2.9% with 10 i.u. PMSG to 10.5% with 15 i.u. PMSG. In zygote stage, the proportion of polyploid embryos also increased as the dose increased, from 1.9% in 5 i.u. to 6.7% in 15 i.u. PMSG. It was observed that the extra chromosomal set in polyploidy embryos originated by both fertilization of a diploid oocyte and dispermy.
  
  
  CONCLUSIONS
  These results indicate a dose-response relationship between the PMSG dose and the incidence of polyploidy in the CD-1 mouse. Both a disturbance at maturation division and an error at fertilization were the cause of polyploidy.
authors.affiliation: Department of Obstetrics and Gynecology, University of British Columbia, Vancouver, Canada.
authors.forename: S
authors.initials: S
authors.lastname: Ma
authors.forename: D K
authors.initials: DK
authors.lastname: Kalousek
authors.forename: B H
authors.initials: BH
authors.lastname: Yuen
authors.forename: Y S
authors.initials: YS
authors.lastname: Moon
mesh_terms: D000782:Aneuploidy; D000818:Animals; D002869:Chromosome Aberrations; D004305:Dose-Response Relationship, Drug; D004622:Embryo, Mammalian / Q000187:drug effects / Q000502:physiology*; D005314:Embryonic and Fetal Development; D005260:Female; D006064:Gonadotropins, Equine / Q000494:pharmacology*; D008297:Male; D051379:Mice; D008815:Mice, Inbred Strains; D009865:Oocytes / Q000187:drug effects / Q000502:physiology; D010060:Ovulation / Q000187:drug effects; D011247:Pregnancy; D015053:Zygote
chemical_list: D006064:Gonadotropins, Equine