Fig. 3

Expression of Cspp1, Dlg1, Kdm5c and Rev3 l was higher in developing heads of limnetic than benthic Arctic charr morphs. a Expression correlation of the additional eight candidate genes based on mutual rank (MR) analysis from COXPRESdb in mammalian species. The stronger correlations represented in darker green shading and with one, two and three asterisks indicating <2000, <1000 and <500 MR numbers, respectively. b Relative expression of the genes in developing heads of SB, LB, PI, PL and AC at six stages. Error bars represent standard deviation calculated from two biological replicates where each biological replicate contains a homogenate of six heads. c Relative expression ratios were subjected to an analysis of variance (ANOVA) to test for expression differences among five Arctic charr morphs and six stages (M morph; T stage (time); MxT morphs by time effects; P values of <0.05, 0.01 and 0.001 are indicated by one, two and three asterisks, respectively). Subsequently, a post hoc Tukey’s HSD test was performed to analyse the expression of candidates among the morphs. Green to red colour gradient of morphs represent low to high expression levels and morphs with no connecting line have significantly different expression (α = 0.05). The bold and underlined genes displayed lower expression levels in the benthic morphs. d Pearson correlation coefficient (r) was used to assess the pairwise expression similarity between the candidate genes during craniofacial development. Blue represents positive expression correlation (the colour gradient showing critical values of r, 2-tail; df = 28). P values of <0.05, 0.01 and 0.001 are indicated by one, two and three asterisks, respectively