'Identical' cells? Not so much

Genetically identical cells may be far more different than previously believed. Published this week in linkurl:Science,;http://www.sciencemag.org/ researchers find striking variation in levels of gene expression among individual, genetically identical E. coli, seemingly the result of simple chance. "The paper is quite rich," said linkurl:Sanjay Tyagi,;http://www.phri.org/research/res_pityagi.asp a molecular biologist at New Jersey Medical School who was not involved in the research. "People think that if an organism has a particular genotype, it determines its phenotype -- that there's a one-to-one relationship," said Tyagi. "But as it turns out, [differences in gene expression] can arise just from chance."

Microfluidic device allows multiplex imaging of library strains. Image courtesy of Yuichi Taniguchi, Paul Choi, Gene-wei Li, and Huiyi Chen, Harvard University

In traditional gene expression studies, researchers grind up a population of cells, then identify overall amounts of gene products from the resulting mixture. Researchers at Harvard University instead studied cells...