Overall MHC expression through ontogeny. Expression in fragments per kilobase of transcript length per million reads mapped (FPKM) of all MHC-I, MHC-II (MHC-IIA+MHCIIB), and MHC-I-like1 and MHC-I-like2 sequences through the ontogeny. Points are expression values (summed over all transcripts of a given MHC category) for RNA-seq libraries (Supplemental Table S4), and bars are averages across libraries for each species and stage. Species abbreviations: (Ia) I. alpestris, (Lb) L. boscai, (Lh) L. helveticus, (Lv) L. vulgaris, (Pw) P. waltl, (Tc) T. cristatus, (Tm) T. marmoratus.