title: Analysis of the sex ratio in preimplantation embryos from B6.K1 and B6.K2 Ped gene congenic mice.
abstract: OBJECTIVE
  The mouse preimplantation embryo development (Ped) gene product, Qa-2, which is the homolog of human HLA-G, influences the rate of preimplantation embryonic development and overall reproductive success. The sex ratio in preimplantation embryos from Ped gene congenic mice was examined in order to determine whether embryo sex is a confounding factor in the control of the rate of preimplantation development.
  
  
  METHODS
  B6.K1 (Ped slow) and B6.K2 (Ped fast) congenic mice differ only in the absence (B6.K1) or presence (B6.K2) of the genes encoding Qa-2 protein. We analyzed the sex of B6.K1 (n=221) and B6.K2 (n=260) preimplantation embryos by using Real-Time PCR with primers specific for the X and Y chromosomes.
  
  
  RESULTS
  We found that there was no statistically significant difference in the ratio of male to female preimplantation embryos in either strain.
  
  
  CONCLUSIONS
  We conclude that the sex of the embryos is not a confounding factor that affects the Ped gene control of the rate of preimplantation development. Therefore, the Ped gene is entirely responsible for mediating the faster development of B6.K2 embryos compared to B6.K1 embryos.
authors.affiliation: Department of Biology, Northeastern University, 134 Mugar Hall, Boston, MA 02115, USA.
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Byrne
authors.forename: Judith A
authors.initials: JA
authors.lastname: Newmark
authors.forename: Carol M
authors.initials: CM
authors.lastname: Warner
mesh_terms: D000818:Animals; D001755:Blastocyst; D017931:DNA Primers; D047108:Embryonic Development / Q000235:genetics*; D005260:Female; D006649:Histocompatibility Antigens / Q000235:genetics; D008297:Male; D051379:Mice; D020297:Mice, Congenic / Q000235:genetics*; D016133:Polymerase Chain Reaction; D019849:Sex Determination Processes; D012737:Sex Factors; D012744:Sex Ratio
chemical_list: D017931:DNA Primers; D006649:Histocompatibility Antigens