Fig. 2

Synteny of the genomic regions of (a) α1- atp1a1, (b) α2- atp1a2, and (c) α3- atp1a3. NKA gene isoforms among various species were shaded. Various atp1a1 isoforms in tilapia are located on a side by side locus on same chromosomes, suggesting their formation were the results of tandem duplications. Stickleback α1 isoforms was hidden at the genomic level as alternative transcription between α1a/b and α1c generates a chimeric α1 isoform. Five zebrafish α1 genes on Chromosome 1 are alternatively transcribed to form seven known α1 transcripts. Teleost α3a and α3b (atp1a3a and atp1a3b) are located on different chromosomes with highly conserved neighbor gene synteny in both tilapia and medaka, suggesting that the isoforms were the result of the 3R whole genome duplication in teleosts. Various colors indicate different isoforms and gradient colors indicate the isoforms cannot be distinguished: α1a (blue); α1b (green); α1a/b (gradient blue to green); α2 (magenta); α3a (yellow); α3b (brown); and α3a/b (gradient yellow to brown). The chromosomal directions of the genes are indicated by arrows. Connecting lines indicate orthologous genes