Using two distinct methods, Whitehead Institute researchers have successfully and consistently manipulated targeted genes in both human embryonic stem (ES) cells and induced pluripotent stem (iPS) cells (adult cells that have been reprogrammed to an embryonic stem cell-like state).
In one case, scientists employed proteins known as zinc finger nucleases (ZFNs) to change a single base pair in the genome, allowing them either to insert or remove mutations known to cause early-onset Parkinson’s disease (PD). The second method relies on proteins called transcription activator like effector nucleases (TALENs) capable of altering specific genes with similar efficiency and precision as ZFNs.
Tweaking the levels of factors used during the reprogramming of adult cells into induced pluriopotent stem (iPS) cells greatly affects the quality of the resulting iPS cells, according to Whitehead Institute researchers.
“This conclusion is something that I think is very surprising or unexpected—that the levels of these reprogramming factors determine the quality of the iPS cells,” says Whitehead Founding Member Rudolf Jaenisch. “We never thought they’d make a difference, but they do.”
An article describing this work is published in the December 2 issue of Cell Stem Cell.
“This conclusion is something that I think is very surprising or unexpected—that the
By irradiating typical polystyrene lab plates with ultraviolet (UV) waves, Whitehead Institute and MIT scientists have created a surface capable of tripling the number of human embryonic stem (ES) and induced pluripotent stem (iPS) cells that can be grown in culture by current methods. Use of this novel surface also eliminates the need for layers of mouse “feeder cells” to support ES- and iPS-cell growth.
“Polystyrene is the most common cell culture surface used in labs, and to be able to do a simple treatment and get something that works better than the mouse feeder layers is great and potentially
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Whitehead Institute researchers have developed a novel method of removing potential cancer-causing genes during the reprogramming of skin cells from Parkinson’s disease patients into an embryonic-stem-cell-like state. Scientists were then able to use the resulting induced pluripotent stem (iPS) cells to derive dopamine-producing neurons, the cell type that degenerates in Parkinson’s disease patients.
The work marks the first time researchers have generated human iPS cells that have maintained their embryonic stem-cell-like properties after the removal of reprogramming genes. The findings are published in the March 6 edition of the journal Cell.
Removing the reprogramming genes is also important because