Wells D, Bermudez MG, Steuerwald N, Thornhill AR, Walker DL, Malter H, Delhanty JDA, Cohen J. Expression of genes regulating chromosome segregation, the cell cycle and apoptosis during human preimplantation development.
Hum Reprod 2005;
20:1339-48. [PMID:
15705620 DOI:
10.1093/humrep/deh778]
[Citation(s) in RCA: 117] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
BACKGROUND
Appropriate gene expression is vital for the regulation of developmental processes. Despite this fact there is a remarkable paucity of information concerning gene activity during preimplantation development.
METHODS
We employed reverse transcription and real-time fluorescent PCR to quantify the expression of nine genes (BRCA1, BRCA2, ATM, TP53, RB1, MAD2, BUB1, APC and beta-actin) in oocytes and embryos. A full characterization of all genes was achieved in 42 embryos and four oocytes. The genes analysed have a variety of important cellular functions.
RESULTS
Oocytes displayed relatively high levels of mRNA transcripts, while 2-3-cell embryos were seen to contain very little mRNA from any of the genes examined. Recovery of expression levels was not seen until the 4-cell stage or later, with the presumptive activation of the embryonic genome. Some genes displayed sharp increases in expression in embryos composed of 4-8 cells, but, for most, maximum expression was not achieved until the blastocyst stage.
CONCLUSIONS
Our data show that it is possible to define characteristic gene expression profiles for each stage of human preimplantation development. The identification of genes active at defined preimplantation phases may provide clues to the cellular pathways utilized at specific stages of development. Expression of genes that function in DNA repair pathways indicate that DNA damage may be common at the cleavage stage. We suggest that specific patterns of gene expression may be indicative of embryo implantation potential.
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