Three retroduplications in D. melanogaster. For each gene pair, coding sequences of transcripts were aligned to determine the most similar transcripts between parent gene and retrogene. Black bars indicate coding sequence, grey bars indicate untranslated regions, and thin lines indicate introns. Dashed lines show intron loss from parent gene to retrogene. Gene models were obtained from FlyBase. (a) CG4960 is a retroduplication of either CG8331-RA (shown) or CG8331-RD, which encodes identical proteins. (b) CG17734-RA gave rise to CG11825. CG11825-RA is the retrogene transcript with the highest level of sequence identity to any transcript of CG17734. (c) Sep2 encodes a single transcript. Sep5 encodes 2 transcripts, Sep5-RA (shown) and Sep5-RB, which both contain identical coding sequence.