Simulated validation of the detection of intron-less transgenes using DELLY for gene-doping control in horse sports. Equus caballus

Gene doping is prohibited in horseracing. In this study, we validated the detection sensitivity of DELLY using artificially generated sequence data of 12 target genes. With DELLY, at least one intron was detected as a deletion in eight targeted genes using the 150-bp PE read WGS data, whereas all targeted genes were detected by DELLY using the 100-bp PE read data. The detection sensitivity was higher in 100-bp PE reads than in 150-bp PE reads, despite a lower total sequence coverage, probably because of tolerance of mismatch between the mapped reads and reference genome. In addition, it was observed that the average intron size detected by SR alone was 293 bp and that detected by both SR and PE was 8,924 bp. Thus, we showed that transgenes with various intron-exon structures could be detected using DELLY, suggesting its application in gene-doping control in horses.