Related Experiment Video
Updated: Jul 13, 2026

Combined DNA-RNA Fluorescent In situ Hybridization (FISH) to Study X Chromosome Inactivation in Differentiated Female Mouse Embryonic Stem Cells
Published on: June 14, 2014
X-Chromosome inactivation in cloned mouse embryos
K Eggan1, H Akutsu, K Hochedlinger
1Whitehead Institute for Biomedical Research and Department of Biology, Massachusetts Institute of Technology, 9 Cambridge Center, Cambridge, MA 02142, USA.
Cloning resets epigenetic marks on X chromosomes in mouse embryos. The study shows that epigenetic marks can be removed and reestablished during cloning, influencing X chromosome inactivation patterns.
Area of Science:
- Epigenetics
- Developmental Biology
- Reproductive Science
Background:
- Epigenetic differences exist between the two X chromosomes in female somatic cells.
- X chromosome inactivation (XCI) is a crucial process in female mammals for dosage compensation.
- Understanding epigenetic reprogramming during cloning is vital for developmental biology.
Purpose of the Study:
- To investigate if cloning resets epigenetic differences between the two X chromosomes in a somatic female nucleus.
- To analyze X chromosome inactivation patterns in cloned mouse embryos.
- To compare epigenetic marks imposed during gametogenesis versus somatic XCI.
Main Methods:
- Monitoring X inactivation in cloned mouse embryos.
- Utilizing somatic cells and embryonic stem cells as nuclear donors.
- Analyzing X inactivation patterns in the embryo proper and trophectoderm (TE).
Main Results:
- Both X chromosomes were active during cleavage of cloned embryos.
- Random X inactivation occurred in the embryo proper.
- Nonrandom X inactivation was observed in the trophectoderm (TE), with the donor's inactive X being preferentially inactivated.
- When using embryonic stem cells, random X inactivation was observed in both TE and embryo.
Conclusions:
- Epigenetic marks on X chromosomes can be removed and reestablished during the cloning process.
- Cloning can reset and re-impose epigenetic marks on X chromosomes.
- The epigenetic marks established during gametogenesis for imprinted XCI in TE are functionally equivalent to those established during somatic XCI.
More Related Videos
Related Concept Videos
In-vitro Mutagenesis
X-Inactivation
Inheritance of Chromatin Structures
The Ratio of X Chromosome to Autosomes
Normal male Drosophila has a ratio of one X chromosome to two sets of autosomes. In contrast, normal female Drosophila...
Dosage Compensation
In addition to sexual development, the X chromosome has genes involved in autosomal functions such as brain development and the immune system. Therefore, males and females with distinct numbers of X chromosomes will have...
X-inactivation

