Expression of apoptosis-related genes in human oocytes and embryos.
OBJECTIVE
The objective was to study whether apoptosis occurs in human embryogenesis.


METHODS
Human viable, arrested, and nonviable embryos and immature, and nonfertilized oocytes donated by our patients were used to detect apoptosis by Tunel labeling, annexin staining, and single-cell reverse transcriptase-polymerase chain reaction (RT-PCR).


RESULTS
DNA fragmentation and phosphotidylserine translocation, the two markers for apoptosis, were detected frequently in fragmented human embryos derived from in vitro fertilization-embryo transfer (IVF-ET). Using RT-PCR, apoptotic genes also were detected in these embryos. The frequencies of gene expression in viable embryos, arrested embryos, nonviable embryos, immature oocytes, and non-fertilized oocytes were: 7/8, 5/5, 5/6, 0/6, 0/3, for Bax; 8/8, 5/5, 7/7, 0/4, 0/5 for Fas; 2/8, 0/2, 0/3, 0/5, 0/3 for BCL-2; 0/8, 1/3, 0/2, 0/3, 0/2 for Fas-ligand; and 8/8, 17/17, 21/21, 24/24, 15/15 for actin, respectively.


CONCLUSIONS
Our preliminary data did not show a significant difference in the expression frequency of all studied genes between viable embryos and nonviable or arrested embryos. However, the expression of Bax and Fas was noticeably higher in nonviable embryos than in viable embryos as judged by the intensities of amplicons visualized after ethidium bromide staining. In addition, BCL-2 was only detected in viable embryos. Whether embryos quality is related to the regulation of BCL-2, Bax, and Fas expressions requires further study.
Liu
H C
HC
Center for Reproductive Medicine and Infertility, Weill Medical College of Cornell University, New York, New York, USA.
He
Z Y
ZY
Mele
C A
CA
Veeck
L L
LL
Davis
O
O
Rosenwaks
Z
Z
D000199:Actins / Q000235:genetics; D017304:Annexin A5 / Q000378:metabolism; D017209:Apoptosis / Q000235:genetics*; D001706:Biopsy; D001757:Blastomeres / Q000473:pathology; D053938:DNA Fragmentation; D004624:Embryo Transfer; D004622:Embryo, Mammalian / Q000166:cytology / Q000502:physiology*; D053222:Fas Ligand Protein; D005260:Female; D005307:Fertilization in Vitro; D005786:Gene Expression Regulation; D006801:Humans; D020287:In Situ Nick-End Labeling / Q000379:methods; D008562:Membrane Glycoproteins / Q000235:genetics; D009336:Necrosis; D009865:Oocytes / Q000166:cytology / Q000502:physiology*; D011518:Proto-Oncogene Proteins / Q000235:genetics; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction; D051028:bcl-2-Associated X Protein; D019014:fas Receptor / Q000235:genetics
D000199:Actins; D017304:Annexin A5; C494826:BAX protein, human; C505661:FASLG protein, human; D053222:Fas Ligand Protein; D008562:Membrane Glycoproteins; D011518:Proto-Oncogene Proteins; D019253:Proto-Oncogene Proteins c-bcl-2; D051028:bcl-2-Associated X Protein; D019014:fas Receptor