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Blastomere Explants to Test for Cell Fate Commitment During Embryonic Development
Published on: January 26, 2013
Evidence that human blastomere cleavage is under unique cell cycle control
Ann A Kiessling1, Ritsa Bletsa, Bryan Desmarais
1Department of Obstetrics and Gynecology, Athens Medical School, Alexandra Maternity Hospital, Athens, Greece. kiessling@bedfordresearch.org
Journal of Assisted Reproduction and Genetics
|March 17, 2009
Summary
Early human embryo development involves unique molecular pathways. Genes related to circadian rhythm and cell division, including UHRF2, MYC, and CLOCK, are highly expressed in 8-cell embryos.
Area of Science:
- Developmental Biology
- Genomics
- Molecular Biology
Background:
- Understanding early human embryo development is crucial for reproductive medicine and developmental biology.
- Gene expression patterns in early human embryos provide insights into fundamental biological processes.
Purpose of the Study:
- To elucidate the molecular pathways governing early human embryonic development.
- To characterize gene expression profiles in 8-cell human embryos.
Main Methods:
- Utilized improved linear amplification of messenger RNAs (mRNAs).
- Performed whole human genome microarray analyses.
- Compared gene expression in 8-cell human embryos with human fibroblasts and pluripotent stem cells.
Main Results:
- Identified overexpression of genes involved in circadian rhythm and cell division in 8-cell embryos.
- Observed silence of canonical cell cycle checkpoints (RB and WEE1).
- Noted significant upregulation of tumor suppressor UHRF2 (>10-fold), proto-oncogene MYC, and circadian rhythm core element CLOCK (>50-fold).
Conclusions:
- Canonical G1 and G2 cell cycle checkpoints appear inactive in totipotent human blastomeres.
- UHRF2, MYC, and intracellular circadian pathways may substitute for canonical checkpoints.
- These pathways likely play critical roles in regulating early human development.
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