Principal components analyses (PCA) of steady-state chemostat cultures. The x and y axes represent the two main principal components (PC1, PC2), the groups responsible for the majority of the variance in each global dataset (see Materials and methods). PCA and growth-rate trends (dashed lines) at the (a) transcriptome (mRNA) level and (b) proteome level. (c,e) PCA and trends at the (c) endometabolome and (e) exometabolome level, respectively. (d,f) Same as (c) and (e) for carbon-sufficient chemostat series (N-, P- and S- limited series; see text for explanation). Each symbol represents a culture condition, colored as follows: red, carbon (C) limitation; blue, nitrogen (N) limitation; yellow, phosphate (P) limitation; green, sulfate (S) limitation. The symbol shape indicates the specific growth rate, μ, of the culture: ovals, μ = 0.07/h; triangles, μ = 0.1/h; rectangles, μ = 0.2/h. The circle round the blue ovals includes chemostat series exhibiting pseudohyphal growth (see text). As a test of reproducibility, for each nutrient-limiting condition, one of the three μ = 0.07/h exometabolome samples was analyzed in triplicate.
Castrillo et al. Journal of Biology 2007 6:4 doi:10.1186/jbiol54