We define a measure of cooperativity for gene regulatory networks which we propose should be maximized under a demand for energy efficiency . We investigate its dependence on network size, connectivity and the fraction of repressory/activatory interactions. Next, we consider the cell-cycle regulatory network of the  yeast, Saccharomyces cerevisiae, as a case study and calculate its degree of cooperativity . A comparison with random networks of similar size and composition reveals that the yeast's cell-cycle regulation is exceptionally cooperative .
We define a measure of coherent activity for gene regulatory networks , a property that reflects the unity of purpose between the regulatory agents with a common target. We propose that such harmonious regulatory action is desirable under a demand for energy efficiency and may be selected for under evolutionary pressures. We consider two recent models of the cell-cycle regulatory network of the budding yeast, Saccharomyces cerevisiae, as a case study and calculate their degree of coherence . A comparison with random networks of similar size and composition reveals that the yeast's cell-cycle regulation is wired to yield and exceptionally high level of coherent regulatory activity. We also investigate the mean degree of coherence as a function of the network size, connectivity and the fraction of repressory/activatory interactions .
R
cooperativity
coherent activity
R
which we propose should be maximized
, a property that reflects the unity of purpose between the regulatory agents with a common target. We propose that such harmonious regulatory action is desirable
R
. We investigate its dependence on network size, connectivity and the fraction of repressory/activatory interactions. Next, we consider
and may be selected for under evolutionary pressures. We consider two recent models of
A
budding
R
its degree of cooperativity
their degree of coherence
R
exceptionally cooperative
wired to yield and exceptionally high level of coherent regulatory activity. We also investigate the mean degree of coherence as a function of the network size, connectivity and the fraction of repressory/activatory interactions