Cytogenetics of postimplantation rabbit conceptuses following delayed fertilization.
The chromosome complement and anatomical development of 10-16-day rabbit embryos were studied following delayed fertilization. Preimplantation loss was 40% in the experimental group compared with 17% in control animals. Also, a greater number of embryos retarded in growth or with structural anomalies was seen in the delayed-mated group. Cytogenetic analysis revealed a trisomy for a small metacentric chromosome in 104 control embryos. Only 1 triploid embryo was found in 84 implantation sites from rabbits that had been delayed mated. The incidence of triploidy postimplantation was much less than the 13% found previously in 6-day blastocyts. Increased embryonic loss at the time of or shortly after implantation may be responsible for the discrepancy.
D000818:Animals; D002869:Chromosome Aberrations; D025063:Chromosome Disorders; D000013:Congenital Abnormalities / Q000196:embryology; D003338:Corpus Luteum / Q000166:cytology; D004171:Diploidy; D020964:Embryo Loss; D004622:Embryo, Mammalian / Q000648:ultrastructure; D005260:Female; D005306:Fertilization; D007621:Karyotyping; D008297:Male; D011247:Pregnancy; D011817:Rabbits; D012729:Sex Chromosome Aberrations; D012730:Sex Chromosomes; D013997:Time Factors; D014314:Trisomy