For example, if a yeastcell was genetically modified to include a particular gene, this technique would allow the expression of that gene to come under precise control.
The researchers also are developing protein-network maps for other organisms, including a yeastcell and Caenorhabditis elegans, a tiny worm with some 19, 000 genes, about the same number as humans.
In the yeastcell, they found only about a quarter of the genes and proteins appeared to be essential, in that they connected to large numbers of other proteins and substances.