Presentation Title

Utilizing Embryonic Stem Cells to Discover a Direct Correlation Between the PGC7 gene and X-chromosome Inactivation

Faculty Mentor

Xiaochun Yu, Ph.D.

Start Date

17-11-2018 12:30 PM

End Date

17-11-2018 2:30 PM

Location

HARBESON 36

Session

POSTER 2

Type of Presentation

Poster

Subject Area

health_nutrition_clinical_science

Abstract

Utilizing Embryonic Stem Cells to Discover a Direct Correlation Between the PGC7 gene and X-chromosome Inactivation

Abstract:

One of the copies of the X chromosome present in female mammals is inactivated during early embryonic development. X-chromosome inactivation is an essential process in early female embryonic development. As nearly all female mammals have two X chromosomes, X-inactivation prevents them from having twice as many X chromosome gene products as males, who only possess a single copy of the X chromosome. When one of the X-chromosomes does not inactivate during this stage, the developing embryo immediately dies, due to a 'dosage' imbalance of genes. If the X-chromosome is slightly or incorrectly inactivated, the female will survive, but will live with a variety of diseases, such as Rett syndrome, Duchenne's muscular dystrophy, and hemophilia B. It has been established that DNA methylation correlates directly with X-chromosome inactivation. PGC7 (also known as Stella or DPPA3) is an important maternal factor for protecting DNA methylation. PGC7 is a gene that is mainly expressed in the germ cells. It is still unknown if the PGC7 gene plays a role during the process of X-chromosome inactivation. Thus, in this study, embryonic stem cells (ES) were isolated from the PGC7 mutant mice. Then genotyping was performed to determine the PGC7 mutation in these cell lines. ES4 was identified as the PGC7-/-(knockout) cell line, meaning that the PGC7 gene was not present. Differentiation was then induced in ES4. After differentiation, Xist RNA FISH was performed in the ES4 cells to detect the X chromosome inactivation. Compared to the PGC7+/- female ES cells (ES1) which contained PGC7, the PGC7 deficient female ES cells show a significant loss of X-inactivation.

References

"Embryonic Stem Cell Markers." Embryonic Stem Cell Markers. N.p., n.d. Web. 03 Aug. 2016.

Kang, Jinsuk, Sundeep Kalantry, and Anjana Rao. "PGC7, H3K9me2 and Tet3: Regulators of DNA Methylation in Zygotes." Cell Research. Nature Publishing Group, Jan. 2013. Web. 03 Aug. 2016.

Lee, J.T., and Lu, N. (1999). Targeted mutagenesis of Tsix leads to nonrandom X inactivation. Cell 99, 47–57.

Peeters, Samantha B., Allison M. Cotton, and Carolyn J. Brown. "Variable Escape from X-chromosome Inactivation: Identifying Factors That Tip the Scales towards Expression." Bioessays. Blackwell Publishing Ltd, Aug. 2014. Web. 03 Aug. 2016.

"Result Filters." National Center for Biotechnology Information. U.S. National Library of Medicine, n.d. Web. 03 Aug. 2016.

Sharp, Andrew J., Elisavet Stathaki, Eugenia Migliavacca, Manisha Brahmachary, Stephen B. Montgomery, Yann Dupre, and Stylianos E. Antonarakis. "DNA Methylation Profiles of Human Active and Inactive X Chromosomes." Genome Research. Cold Spring Harbor Laboratory Press, Oct. 2011. Web. 03 Aug. 2016.

X Chromosome-wide Analyses of Genomic DNA Methylation States and Gene Expression in Male and Female Neutrophils." X Chromosome-wide Analyses of Genomic DNA Methylation States and Gene Expression in Male and Female Neutrophils. N.p., n.d. Web. 03 Aug. 2016.

Summary of research results to be presented

Results:

The XIST RNA staining results show that in the PGC7-/- (deficient) cells, there was no X-inactivation. The PGC7+/- cells had X-chromosome inactivation. The cells containing the PGC7 gene had X-chromosome inactivation while the knockout cells that were PGC7 deficient did not. This supports and proves the statement that PGC7 is directly involved with X-chromosome inactivation during the early development of female embryos. Although this was only proved in mice, it is still a very significant finding. It allows for better understanding of the mechanisms involved in X-chromosome inactivation. In the future, this study can hopefully be performed in humans to determine if the PGC7 gene has the same function in humans as it does in mice. Furthermore, once the process of X-chromosome inactivation is more fully understood, steps can be taken to prevent incorrect X-inactivation and the diseases that can come with it.

This document is currently not available here.

Share

COinS
 
Nov 17th, 12:30 PM Nov 17th, 2:30 PM

Utilizing Embryonic Stem Cells to Discover a Direct Correlation Between the PGC7 gene and X-chromosome Inactivation

HARBESON 36

Utilizing Embryonic Stem Cells to Discover a Direct Correlation Between the PGC7 gene and X-chromosome Inactivation

Abstract:

One of the copies of the X chromosome present in female mammals is inactivated during early embryonic development. X-chromosome inactivation is an essential process in early female embryonic development. As nearly all female mammals have two X chromosomes, X-inactivation prevents them from having twice as many X chromosome gene products as males, who only possess a single copy of the X chromosome. When one of the X-chromosomes does not inactivate during this stage, the developing embryo immediately dies, due to a 'dosage' imbalance of genes. If the X-chromosome is slightly or incorrectly inactivated, the female will survive, but will live with a variety of diseases, such as Rett syndrome, Duchenne's muscular dystrophy, and hemophilia B. It has been established that DNA methylation correlates directly with X-chromosome inactivation. PGC7 (also known as Stella or DPPA3) is an important maternal factor for protecting DNA methylation. PGC7 is a gene that is mainly expressed in the germ cells. It is still unknown if the PGC7 gene plays a role during the process of X-chromosome inactivation. Thus, in this study, embryonic stem cells (ES) were isolated from the PGC7 mutant mice. Then genotyping was performed to determine the PGC7 mutation in these cell lines. ES4 was identified as the PGC7-/-(knockout) cell line, meaning that the PGC7 gene was not present. Differentiation was then induced in ES4. After differentiation, Xist RNA FISH was performed in the ES4 cells to detect the X chromosome inactivation. Compared to the PGC7+/- female ES cells (ES1) which contained PGC7, the PGC7 deficient female ES cells show a significant loss of X-inactivation.

References

"Embryonic Stem Cell Markers." Embryonic Stem Cell Markers. N.p., n.d. Web. 03 Aug. 2016.

Kang, Jinsuk, Sundeep Kalantry, and Anjana Rao. "PGC7, H3K9me2 and Tet3: Regulators of DNA Methylation in Zygotes." Cell Research. Nature Publishing Group, Jan. 2013. Web. 03 Aug. 2016.

Lee, J.T., and Lu, N. (1999). Targeted mutagenesis of Tsix leads to nonrandom X inactivation. Cell 99, 47–57.

Peeters, Samantha B., Allison M. Cotton, and Carolyn J. Brown. "Variable Escape from X-chromosome Inactivation: Identifying Factors That Tip the Scales towards Expression." Bioessays. Blackwell Publishing Ltd, Aug. 2014. Web. 03 Aug. 2016.

"Result Filters." National Center for Biotechnology Information. U.S. National Library of Medicine, n.d. Web. 03 Aug. 2016.

Sharp, Andrew J., Elisavet Stathaki, Eugenia Migliavacca, Manisha Brahmachary, Stephen B. Montgomery, Yann Dupre, and Stylianos E. Antonarakis. "DNA Methylation Profiles of Human Active and Inactive X Chromosomes." Genome Research. Cold Spring Harbor Laboratory Press, Oct. 2011. Web. 03 Aug. 2016.

X Chromosome-wide Analyses of Genomic DNA Methylation States and Gene Expression in Male and Female Neutrophils." X Chromosome-wide Analyses of Genomic DNA Methylation States and Gene Expression in Male and Female Neutrophils. N.p., n.d. Web. 03 Aug. 2016.