design: Total RNA was extracted from synaptosome-enriched fractions and whole brain tissue of adult zebrafish (fmr1-/- and WT). Libraries were prepared using Illumina TruSeq protocol after rRNA depletion (Ribo-Zero). Sequencing was performed on an Illumina HiSeq 2500 platform (paired-end). Data was generated to analyze circular RNA (circRNA) abundance and circular-to-linear ratios (CLR).