Chromosomal instability in rhesus macaque preimplantation embryos

Objective: To establish a relevant animal model to systematically investigate chromosomal instability in human oocytes and preimplantation embryos. Design: Prospective rhesus monkey IVF study. Setting: Academic laboratory, Oregon National Primate Research Center and Caribbean Primate Research Center. Animal(s): Young rhesus macaque females. Intervention(s): In vitro produced entire rhesus macaque preimplantation embryos were cytogenetically assessed using a five-color fluorescent in situ hybridization assay developed for rhesus macaque chromosomes homologous to human chromosomes 13, 16, 18, X, and Y, using human bacterial artificial chromosome probes. Main Outcome Measure(s): Chromosomal abnormality rates in preimplantation embryos from young rhesus macaque females were established. Result(s): Fifty preimplantation embryos, displaying good morphology and normal development, were analyzed from 11 young rhesus macaque females. Overall, 27 embryos (54%) were normal, 11 embryos (22%) mosaic, 3 embryos (6%) chaotic, 2 embryos (4%) aneuploid, 3 embryos (6%) haploid, and 4 embryos (8%) triploid. Conclusion(s): These data indicate that in vitro produced rhesus macaque and human preimplantation embryos exhibit similar numerical chromosomal aberrations. Rhesus macaques appear to be a suitable animal model for investigating the origin of chromosomal instability observed in human preimplantation embryos.