Fig. 1.

Study design. We examined three potential patterns of differential expression between electric organ (EO) and skeletal muscle (SM) in this study: differential expression of gene paralogs, differential expression of alternatively spliced mRNA transcripts and differential spatial expression of proteins. The first two differences were analyzed using a combination of suppressive subtractive hybridization (SSH) and reverse transcription PCR (RT-PCR) (see Materials and methods), whereas spatial distribution of proteins was analyzed using widely cross-reactive antibodies that did not recognize specific paralogs or alternative splice variants (see Materials and methods). We list examples of each pattern we detected using these methods, which are explained in more detail in the Results.