Fig. 2

Maternal mRNA abundance of candidate reference and target genes. a mRNA abundance of candidate reference genes based on raw Cq values across all of the species. In each box plot, the middle line represents the median and boxes’ lower and upper limits indicate the 25/75 percentiles. b Correlation between average mRNA abundance of the reference genes, in eggs of haplochromine cichlids and zebrafish. c Comparisons of maternal mRNA abundance for candidate target genes across different habitats in East Africa. Asterisks above box plots indicate significantly elevated expression (P < 0.05) compared to the plots matching the colour of the asterisks. The middle line represents the median and boxes’ lower and upper limits indicate the 25/75 percentiles for each plot