To pinpoint the relationships between the duplications of teleost khdrbs1 genes, we conducted protein domain analysis by SMART. We found that when compared with human KHDRBS1, both zebrafish KHDRBS1a and KHDRBS1b possessed similar protein domains, though they shared more similarities to spotted gar KHDRBS1a (Figure 4A). Additionally, the differences between genomic intron–exon structures of zebrafish khdrbs1a and khdrbs1b were also analyzed. Both khdrbs1a and khdrbs1b had an intron–exon structure similar to that of other species (Figure 4B), with the highly conserved region within the KH domains (Figure 4C).