title: A Y-chromosomal effect on blastocyst cell number in mice.
abstract: Karyotopic and cell number analysis of 3.5 day post coitum preimplantation mouse embryos was used to determine whether XY embryos had more cells than XX embryos at the late morula/early blastocyst stage. This proved to be the case for the CD1 strain (for which it had previously been shown that XY embryos form a blastocoel earlier than XX embryos) and for the MF1 strain. However, this increased cell number was not seen in MF1 embryos carrying an RIII strain Y in place of the MF1 Y. Furthermore, interstrain crosses between CD1 and the MF1,YRIII strain showed that the cell number increase segregated with the CD1 Y but not with the RIII Y. It is concluded that the CD1 and MF1 Y chromosomes carry a factor that accelerates the rate of preimplantation development.
authors.affiliation: MRC Mammalian Development Unit, London, UK.
authors.forename: P S
authors.initials: PS
authors.lastname: Burgoyne
mesh_terms: D000818:Animals; D001755:Blastocyst / Q000166:cytology*; D001947:Breeding; D002452:Cell Count; D002875:Chromosomes / Q000648:ultrastructure; D047108:Embryonic Development / Q000502:physiology; D005314:Embryonic and Fetal Development / Q000235:genetics*; D005260:Female; D007621:Karyotyping; D051379:Mice; D008815:Mice, Inbred Strains; D011247:Pregnancy; D014998:Y Chromosome / Q000502:physiology*