Tag: Epigenetics

Phase and fluorescence images of conventional (primed) human embryonic stem cells (ESCs) and naïve human ESCs

Whitehead Institute researchers create “naïve” pluripotent human embryonic stem cells

July 24, 2014

Embryonic stem cell (ESC) research has been hampered by the inability to transfer research and tools from mouse ESC studies to their human counterparts, in part because human ESCs are “primed” and slightly less plastic than the mouse cells. Now researchers in the lab of Whitehead Institute Founding Member Rudolf Jaenisch have discovered how to manipulate and maintain human ESCs into a “naïve” or base pluripotent state similar to that of mouse ESCs without the use of any reprogramming factors.

Artistic image of silhouetted heads

Gene essential for memory extinction could lead to new PTSD treatments

September 18, 2013

A new study from a team of Whitehead and MIT researchers reveals a gene that is critical to the process of memory extinction. Enhancing the activity of this gene, known as Tet1, might benefit people with posttraumatic stress disorder (PTSD) by making it easier to replace fearful memories with more positive associations.

Model for a function for Mot3 prion switching in teh repiro-fermentative cycle of wine yeasts

Protective prion keeps yeast cells from going it alone

March 28, 2013

A team of scientists from Whitehead Institute and the University of Texas Southwestern Medical Center has added markedly to the job description of prions as agents of change, identifying a prion capable of triggering a transition in yeast from its conventional single-celled form to a cooperative, multicellular structure. This change, which appears to improve yeast’s chances for survival in the face of hostile environmental conditions, is an epigenetic phenomenon—a heritable alteration brought about without any change to the organism’s underlying genome.

Not all cellular reprogramming is created equal

December 1, 2011

Tweaking the levels of factors used during the reprogramming of adult cells into induced pluriopotent stem (iPS) cells can greatly affect the quality of the resulting iPS cells, according to Whitehead Institute researchers. This finding explains at least in part the wide variation in quality and fidelity of iPS cells created through different reprogramming methods.

Low oxygen levels prevent X chromosome inactivation in human embryonic stem cells

May 13, 2010

Oxygen levels in the lab can permanently alter human embryonic stem (ES) cells, specifically inducing X chromosome inactivation in female cells, according to Whitehead Institute researchers.

Scientists create human embryonic stem cells with enhanced pluripotency

May 3, 2010

Whitehead Institute researchers have converted established human induced pluripotent stem (iPS) cells and human embryonic stem (ES) cells to a base state of greater pluripotency. 

Tracking the molecular pathway to mixed-lineage leukemia

December 15, 2008

The MLL-AF4 fusion protein, which causes the blood cancer called mixed-lineage leukemia (MLL), binds to several genes responsible for early blood cell development. MLL-AF4 also alters the chromatin proteins associated with these genes, a state that is associated with cancer and leukemia progression.

DNA methylation shown to promote development of colon tumors

December 1, 2007

A promising pathway that may lead to prevention, diagnosis and treatment of certain cancers with minimal side effects.

Prions act as stepping stones in evolution

August 18, 2004

When a protein misfolds, the results can be disastrous. An incorrect change in the molecule’s shape can lead to diseases including Alzheimer’s and Huntington’s. But scientists have discovered that misfolded proteins can have a positive side in yeast.

Malignant cancer cells generate mice through cloning

August 8, 2004

Nature can reset the clock in certain types of cancer and reverse many of the elements responsible for causing malignancy, reports a research team led by Whitehead Institute Member Rudolf Jaenisch, in collaboration with Lynda Chin from Dana Farber Cancer Institute. The team demonstrated this by successfully cloning mice from an advanced melanoma cell.

Scientists Show Cloning Leads to Severe Dysregulation of Many Genes

September 11, 2002

New results from Rudolf Jaenisch’s lab at the Whitehead Institute for Biomedical Research confirmed that the cloning process jeopardizes the integrity of an animal’s whole genome. Scientists had suspected this based on studying a mere dozen genes, but the current study, which will be reported online in the Proceedings of the National Academies of Science this week, expansively surveyed 10,000 genes for abnormalities.

Scientists Show Cloning Can Turn Back Developmental Clock and Faithfully Reproduce X-Inactivation

November 23, 2000

Settling a hotly debated issue in the field of cloning, a team of researchers from the Whitehead Institute and the University of Hawaii has shown that the egg can reset the developmental clock of a female adult cell, first reversing and then faithfully reproducing an early genetic event called X-inactivation. X-inactivation is a process by which one of two X chromosomes in female embryos is randomly silenced during development.

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