In 2006, Shinya Yamanaka of Kyoto University figured out how to reprogram fibroblast cells taken from connective tissue in mice into something that looked a lot more like an embryonic stem cell. These so-called induced pluripotent stem cells(iPS cells) have the capacity—with a lot of biochemical coaxing from scientists—to develop into other tissues, such as nerve or muscle cells. Researchers derived the first iPSCs from humans in 2007. Since then, investigators have attempted to use iPS cells in a variety of ways.
While most stem cell researchers have focused on trying to turn iPS cells directly into treatments, a few investigators have taken a different tack. As chronicled in this March 2011 feature article by Stephen S. Hall, some scientists are using iPS cells to develop tissue cultures that have the molecular characteristics of certain ailments such as Lou Gehrig's disease. It is still unclear just how closely these "diseases in a Petri dish" resemble the diseases in actual human beings.
Scientific American also reported at length about iPS stem cells in the May 2010 issue. (Read the full article here, free of charge, for the next month.) Below is a list of Web sites and key research articles that provide further information—both about iPSCs and stem cells in general.
Stem Cell Basics
A primer from the National Institutes of Health on stem cells
Diseases in a Dish Take Off
A 2010 report by Gretchen Vogel on using iPSCs to screen for potential drug treatments
Embryonic Stem Cells 2.0
A 2008 report by Bruce Goldman that provides a good history of the iPS field and the cells' potential uses
The iPSC-EPS gap
A news report about the research that suggests induced pluripotent stem cells retain their genetic memory
Hotspots of aberrant epigenomic reprogramming in human induced pluripotent stem cells
A Salk Institute research study on the epigenetics of induced stem cells