Co-expression, co-differential expression and differential co-expression. As illustrated for the Piedmontese across development, MYOD1 and MYOG are strongly positively co-expressed whereas USP13 and CCNB2 are strongly negatively co-expressed (A). In comparing Piedmontese and Wagyu, PRSS2 and KLK12 are co-ordinately or co-differentially expressed in addition to being co-expressed (B). The differential co-expression arrangement between MSTN and MYL2 is large (+1.1), despite the co-expression strength being relatively modest in the Piedmontese (+0.76) and Wagyu (−0.34) breeds treated separately (C).
Hudson et al. BMC Genomics 2012 13:356 doi:10.1186/1471-2164-13-356