Cytogenetic analysis of human zygotes displaying three pronuclei and one polar body after intracytoplasmic sperm injection

Citation
B. Rosenbusch et al., Cytogenetic analysis of human zygotes displaying three pronuclei and one polar body after intracytoplasmic sperm injection, HUM REPR, 16(11), 2001, pp. 2362-2367
Citations number
22
Categorie Soggetti
Reproductive Medicine","da verificare
Journal title
HUMAN REPRODUCTION
ISSN journal
02681161 → ACNP
Volume
16
Issue
11
Year of publication
2001
Pages
2362 - 2367
Database
ISI
SICI code
0268-1161(200111)16:11<2362:CAOHZD>2.0.ZU;2-L
Abstract
BACKGROUND: Digynic zygotes with three pronuclei and one polar body obtaine d after intracytoplasmic sperm injection (ICSI) were studied cytogeneticall y to elucidate the frequency and origin of chromosomal abnormalities at the earliest stage of conception. METHODS: Uncleaved, single-cell zygotes were incubated with podophyllotoxin and vinblastine and fixed by a gradual fixa tion air drying method. The chromosomes were stained with Giemsa. RESULTS: Twenty-two (50%) out of 44 informative zygotes revealed cytogenetic alterat ions, including aneuploidy (six cells, 13.6%), structural aberrations (10 c ells, 22.7%) and combinations of numerical and structural abnormalities (tw o cells, 4.5%). In one case (2.3%), double aneuploidy or an effect of chrom osomal translocation could not be distinguished and one zygote (2.3%) turne d out tetraploid due to injection of a diploid spermatozoon. Two zygotes (4 .5%) showed an irregular chromatid segregation between the two maternal com plements. In completely analysable cells, the sex chromosome ratio XXX:XXY was 17:15. CONCLUSIONS: Digynic ICSI zygotes carry a high rate of cytogenet ic abnormalities that obviously have been transmitted by the participating oocytes and spermatozoa. We also confirmed the previously reported, possibl y ICSI-induced irregular oocyte chromatid segregation. The results suggest that aneuploidy in the oocytes must have been caused by predivision instead of non-disjunction.