title: Chromosomal constitution of embryos derived from tripronuclear zygotes studied by fluorescence in situ hybridization using probes for chromosomes 4, 13, 18, 21, X, and Y.
abstract: This study was designed to assess the chromosomal constitution and segregation patterns of cleaving embryos derived from tripronuclear zygotes. Thirty-two embryos obtained from 19 conventional IVF patients were analyzed by fluorescence in situ hybridization (FISH) using probes for chromosomes 4, 13, 18, 21, X, and Y. Sixteen embryos (50.0%) exhibited uniform, non-mosaic patterns. These embryos showed pure triploid (n = 7), pure diploid (n = 7), or pure haploid (n = 2). The remaining 16 embryos showed mosaic patterns; 1 was triploid-diploid mosaics, 9 were diploid-haploid, and 4 were haploid only. Autosomal aneuploidy occurred in 2 embryos showing a triploid complement. The sex chromosomal constituent XXX:XXY:XYY was 3:4:2 in embryos showing a pure triploid complement (including 2 embryos with aneuploidy). This ratio was not significantly different from the expected 1:2:1 (p = 0.96). Pure triploid was found in 41.7% of 2-cell embryos, but no triploid complement was found in 3-cell embryos. The present study also supports the diandric origin of tripronuclear zygotes in the conventional IVF, and, to our knowledge, is the first study to use simultaneous six-color FISH for chromosomes 4, 13, 18, 21, X, and Y in human embryos. However, no additive information was obtained about chromosome 4.
authors.affiliation: Institute of Reproductive Medicine and Population, Medical Research Center, Seoul National University, Seoul, Korea.
authors.forename: Myung-Geol
authors.initials: MG
authors.lastname: Pang
authors.forename: Byung-Chul
authors.initials: BC
authors.lastname: Jee
authors.forename: Seok-Hyun
authors.initials: SH
authors.lastname: Kim
authors.forename: Buom-Yong
authors.initials: BY
authors.lastname: Ryu
authors.forename: Sun-Kyung
authors.initials: SK
authors.lastname: Oh
authors.forename: Chang-Suk
authors.initials: CS
authors.lastname: Suh
authors.forename: Shin-Yong
authors.initials: SY
authors.lastname: Moon
mesh_terms: D002869:Chromosome Aberrations; D002877:Chromosomes, Human; D004622:Embryo, Mammalian / Q000502:physiology*; D005307:Fertilization in Vitro; D006801:Humans; D017404:In Situ Hybridization, Fluorescence / Q000379:methods*; D012730:Sex Chromosomes; D015053:Zygote