Fig. 1. Variable N-terminal region of protein isoforms produced by alternative splicing of the Tnt gene in fall armyworm moths and Glanville fritillary butterflies. Alternative exons are colored. Traces on the right show capillary electrophoresis separation of PCR products generated by primers that hybridize on either side of the alternative exon region and from which we determined fragment size and relative abundance. Fragment size measurements match predicted sizes from sequence data. Red peaks are internal size standards. Inset shows western blot of moth flight muscle protein separated by SDS-PAGE and hybridized with MAC 145 antibody specific to insect Tnt. Relative abundances of Tnt F transcripts from the same individuals (below each lane) show agreement with the Tnt F protein isoforms. Specifically, these data show that Tnt F was the predominant protein form when Tnt F transcript relative abundance was high, and was about half of the protein when Tnt F was about 50% of the transcript pool. (Adult moth photo courtesy of Renn Tumlison.)