Fig. 1

Experimental procedure. Type A and type B specimens collected from the wild were dissected to acquire gametes, and the species reciprocally crossed in vitro to generate three different hybrid broods for each alternative parental combination (i.e. six broods in all). At 8 h post fertilization (hpf), embryos were heat shocked at 27 °C for 1 h and a portion of each sample was collected for RNA-Seq. The rest of the embryos were then cultured at normal temperature from 9 hpf and the number of normally and abnormally developing larvae counted after hatching to measure the level of developmental buffering (Additional file 1: Table S3). After RNA-Seq, we conducted edgeR and generalized linear model analysis (glm) respectively to test gene expression level and developmental buffering level