Comparison of regulation frequencies in Carcinus maenas gills in salinity and CO
experiments. (A) Frequency distribution of all gene expression levels in gill 7 and 9 on day 7 as response to short-term hypercapnia (this study). (B) Frequency distribution of all gene expression levels in gill 8 on day 7 as response to low salinity (study of Towle et al. ). Please note the different scaling of the y-axis in (A) and (B). Exposure to low salinity (B) clearly resulted in more genes to be changed on a higher level compared to hypercapnia (A), where levels of change were mainly between a log2-ratio of -0.125 - 0.125. (C) Numbers of genes found to be regulated in expression simultaneously in response to a salinity dilution, as well as short-term hypercapnia (only transcripts with a log2-ratio > |0.200| were considered).