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Updated: Mar 6, 2026
Chromatin Immunoprecipitation Assay for Tissue-specific Genes using Early-stage Mouse Embryos
Published on: April 29, 2011
Expression of specific genes in early mouse embryos blocked by cytochalasin
Reinald Fundele1, Karl Illmensee1, Eva -Maria Jägerbauer1
1Laboratoire de Différenciation Cellulaire, Ecole de Médecine, 20, rue de l'Ecole-de-Médecine, CH-1211, Genève 4.
Abstract:
Mouse embryos at the two cell stage derived from C57BL/6 × C3H/Aa F1-females heterozygous at the X-linked phosphoglycerate kinase locus (Pgk-1) were cultured continuously in the presence of cytochalasin B or D. Further cleavage of the two cell embryos was thus prevented and the embryos became polyploid during culture. The onset of expression of the maternally inherited Pgk-1 gene and of the paternally inherited glucosephosphate isomerase (Gpi-1) gene was determined in these polyploid embryos by cellulose acetate gel electrophoresis of single embryos. In contrast to euploid preimplantation embryos developing normally in utero or in culture without cytochalasins, expression of maternal Pgk-1 was never observed at days 4 and 5 of gestation in polyploid two cell embryos, showing that the Pgk-1 allele on the maternally inherited X chromosome is not activated independently of cytokinesis and morphogenesis. Expression of paternally derived Gpi-1, however, occurred in cleavage blocked embryos von day 5 of development. This may indicate that the activation of two genes which are both expressed during preimplantation development and which both code for glycolytic enzymes, is initiated by different signals.
Insights
Cytochalasin B/D treatment prevented mouse embryo cleavage, causing polyploidy. Maternal Pgk-1 gene expression was blocked, but paternal Gpi-1 gene expression occurred, suggesting different gene activation signals.
Area of Science:
- Developmental Biology
- Genetics
- Molecular Biology
Background:
- X-chromosome inactivation and gene expression in early mammalian development are critical.
- Understanding the regulation of gene activation during preimplantation development is essential.
Purpose of the Study:
- To investigate the role of cytokinesis and morphogenesis in the activation of maternally and paternally inherited genes during mouse preimplantation development.
- To determine if the activation of the phosphoglycerate kinase (Pgk-1) and glucosephosphate isomerase (Gpi-1) genes are regulated by similar or different signals.
Main Methods:
- Mouse embryos at the two-cell stage were cultured with cytochalasin B or D to prevent cleavage and induce polyploidy.
- Gene expression of maternally inherited Pgk-1 and paternally inherited Gpi-1 was analyzed using cellulose acetate gel electrophoresis.
- Polyploid embryos were compared to euploid embryos developing normally.
Main Results:
- Maternal Pgk-1 gene expression was not observed in polyploid embryos at days 4-5, indicating dependence on cytokinesis and morphogenesis.
- Paternally derived Gpi-1 gene expression was detected in cleavage-blocked embryos by day 5.
- These findings suggest differential signaling pathways for the activation of these two glycolytic enzyme genes.
Conclusions:
- Cytokinesis and morphogenesis are necessary for the activation of the maternally inherited Pgk-1 allele.
- The paternally inherited Gpi-1 allele can be activated independently of these processes.
- Gene activation during early development may be initiated by distinct signaling mechanisms.
