New tool isolates RNA within spec...( A team of University of Oregon biolo...)

A team of University of Oregon biologists, using fruit flies, has created a way to isolate RNA from specific cells, opening a new window on how gene expression drives normal development and disease-causing breakdowns.

While DNA (deoxyribonucleic acid) provides an identical genetic blueprint in every cell, RNA (ribonucleic acid) decodes genetic instructions that turn protein molecules on and off in different cell types.

The new tagging method, tested in a variety of subsets of Drosophila brain cells, is described in a paper put on line ahead of regular publication by the journal Nature Methods. Instead of scientists needing to physically separate cell types, they now can inject a chemically modified gene from the one-celled organism Toxoplasma gondii and activate it in only one cell type within a tissue. Only newly generated RNA in this cell type is then tagged and isolated.

"By analyzing RNA from different cell types, we can begin to understand how cellular differences are generated," said lead author Michael R. Miller, a National Science Foundation-funded doctoral student in the lab of Chris Doe, a UO biologist and Howard Hughes Medical Institute (HHMI) investigator. "Our new TU-tagging method should be useful for isolating cell-type specific RNA from other organisms, including mammals, and should be useful in broad areas of research including studies of development, neurobiology and disease."

The new non-toxic, non-invasive method makes it possible to "listen in" to the messages -- in fact, messenger RNA -- that the nucleus is sending each cell, without perturbing the cell, Doe said. "It is much like eavesdropping on a phone conversation, rather than pulling the person out of the house for questioning. The cell has no idea that its RNAs are being 'tagged' for isolation and study. That's good, because we get a more accurate idea of what the cell is saying."

That, Doe added, could be helpful fo
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