Extremely high variability in the S72 intron of the Amazonian cardinal tetra (Paracheirodon axelrodi)

Here, a combination of a DNA screening technique, direct sequencing and cloning was used to carry out a large-scale assessment of intron variability in cardinal tetras – the first to be conducted for an Amazonian forest fish. To the best of the authors' knowledge, the levels of DNA variability reported in this study are the highest ever documented for an intron marker.