Human embryonic stem cellsWIKIMEDIA COMMONS, NISSIM BENVENISTY
Older, established lines of human embryonic stem cells (hESC), such as those that President George W. Bush approved for federal funding in 2001, are different in significant ways than more recently derived cell lines, according to researchers at the University of California, Los Angeles.
UCLA molecular biologist Amander Clark and her colleagues found crucial differences involving RNA functioning between six hESC lines that they developed in the past three years and cell lines derived prior to 2001. They report their results in this week's issue of Human Molecular Genetics.
Clark and her team focused on the process of X chromosome inactivation that every female stem cell undergoes during development. They confirmed that the established hESC lines had already undergone X chromosome inactivation prior to differentiation, ...