Molecular cytogenetics of human single pronucleated zygotes.
The aim of the present study was to use fluorescence in situ hybridization to analyze the chromosome status of zygotes with a single pronucleus from in vitro fertilization (IVF) and intracytoplasmic sperm injection (ICSI) treatment cycles. In addition, we performed immunocytochemical detection of nuclear lamins and histone H3 trimethylated at lysine-9, Me(3)H3K9. Zygotes were processed 24 hours after insemination or injection to assure the absence of asynchrony. In opposition to previous results, we observed 2 pronuclei in 16 of 18 IVF zygotes and 40 of 64 ICSI zygotes, suggesting premature pronuclear breakdown. In IVF and ICSI zygotes, the rate of normal diploidy was only 6 of 16 and 27 of 56, respectively, suggesting that monopronucleated zygotes should not be used in assisted reproductive treatments. The possible mechanisms are discussed and compared to previous studies of monopronucleated zygotes.
Department of Microscopy, Laboratory of Cell Biology, Multidisciplinary Unit for Biomedical Research-UMIB, Institute of Biomedical Sciences Abel Salazar (ICBAS), University of Porto, Rua Jorge Viterbo Ferreira, Porto, Portugal.
Ana Raquel
AR
Azevedo
Department of Genetics, Faculty of Medicine, University of Porto (FMUP), Porto, Portugal.
Maria João
MJ
Pinho
Centre for Reproductive Genetics, Porto, Portugal.
Joaquina
J
Silva
Department of Microscopy, Laboratory of Cell Biology, Multidisciplinary Unit for Biomedical Research-UMIB, Institute of Biomedical Sciences Abel Salazar (ICBAS), University of Porto, Rua Jorge Viterbo Ferreira, Porto, Portugal.
Rosália
R
Sá
Department of Animal Biology, Faculty of Sciences, Centre for Environmental Biology, University of Lisbon, Lisbon, Portugal Instituto Gulbenkian de Ciência, Oeiras, Portugal.
Sólveig
S
Thorsteinsdóttir
Department of Genetics, Faculty of Medicine, University of Porto (FMUP), Porto, Portugal Centre for Reproductive Genetics, Porto, Portugal.
Alberto
A
Barros
Department of Microscopy, Laboratory of Cell Biology, Multidisciplinary Unit for Biomedical Research-UMIB, Institute of Biomedical Sciences Abel Salazar (ICBAS), University of Porto, Rua Jorge Viterbo Ferreira, Porto, Portugal msousa@icbas.up.pt.
Mário
M
Sousa
D000328:Adult; D016022:Case-Control Studies; D002467:Cell Nucleus / Q000378:metabolism / Q000502:physiology*; D020732:Cytogenetic Analysis; D004171:Diploidy; D046149:Embryo Culture Techniques; D004624:Embryo Transfer; D005260:Female; D005307:Fertilization in Vitro; D006657:Histones / Q000378:metabolism; D006801:Humans; D007150:Immunohistochemistry; D017404:In Situ Hybridization, Fluorescence; D034882:Lamins / Q000378:metabolism; D008297:Male; D008745:Methylation; D008875:Middle Aged; D011247:Pregnancy; D018873:Pregnancy Rate; D020554:Sperm Injections, Intracytoplasmic; D055815:Young Adult; D015053:Zygote / Q000378:metabolism / Q000502:physiology*
D006657:Histones; D034882:Lamins
FISH; histone H3; human monopronucleated zygotes; immunocytochemistry; lamins