Responses of Streptococcus gordonii to arginine restriction

Our previous work has indicated that extracellular arginine concentrations may be an important stimulus for gene regulation in S gordonii. Here cells were cultured in a chemically defined medium (CDM) to mid exponential phase . Cultures were split and resuspended in either CDM or CDM lacking arginine. After 30 mins RNA was extracted and gene expression was monitored using an Agilent microarray. Single colour microarrays were used to measure gene expression in four biological replicates of S gordonii cells cultured, with and without arginine restriction.