Figure 1.

Single-copy RP genes have higher mRNA levels than duplicated RPs. For several data sets, a ranking of their measured RP activities is shown, with single-copy RPs marked as orange bars and duplicated RPs marked as blue bars. RPs for which a measurement was missing in a given data set appear as gray bars and are sorted to the bottom of the list. The ranking is shown for our library of RP promoter fusions (leftmost column), for transcription rate measurements using DNA microarrays (Holstege et al. 1998) (second column), and for mRNA abundance measurements using DNA microarrays (David et al. 2006; Lipson et al. 2009) or RNA-seq (Nagalakshmi et al. 2008; Lipson et al. 2009; Yassour et al. 2009). For each data set, the rank-sum test P-value that tests whether the ranking of single-copy RPs is higher than that of duplicated RPs is shown.