Extended Data Fig. 1: Producer/consumer dynamics in liquid batch cultures.
From: Metabolic heterogeneity and cross-feeding within isogenic yeast populations captured by DILAC
Targeted measurements of labelling states in peptides (Methods, introduced later in the main text) were applied to liquid batch cultures grown in SM media with 1% ¹³C glucose and 68 μM unlabelled lysine. Bar heights indicate the average relative abundance of peptides originating from lysine producer and consumer cells. The data shown are the average across the top three fragments for three measured peptides and four biological replicates. Error bars indicate standard deviation. The relative abundances have been scaled to the OD of the culture at the time the sample was taken (that is the first sample was taken at an OD of approximately 0.6 and the final sample at approximately 2.5). The data shown indicate that initially almost all cells in the culture are lysine consumers. Then, a switch from uptake to synthesis occurs, indicated by the absolute abundance of consumer peptides not increasing after timepoint 1. Presumably, the lysine supplement has run out around the time the first sample has been taken and there is a net addition of only producer peptides.
