Fig. 2.

a In the Lethocerus myosin gene structure, light gray bars represent introns and taller boxes represent exons. Numbers above indicate the MXE cluster according to Kollmar and Hatje (2014); numbers below indicate the exon number within the Lethocerus myosin gene. Dark gray boxes represent single exons. MXE clusters 1, 5, 7, 8, 10 and 11 are outlined, numbered and color-coded. Unnumbered white boxes represent MXE clusters 2–4, 6 and 9, for which Lethocerus has single exons but some species have alternatively spliced clusters of MXEs. b The protein sequence is arranged by exon, with MXE clusters outlined and color-coded as in a. Exons 10a, 14b, and 20c are italicized to indicate they are putative exons for which no clone has been found to date