Underestimation of inadvertent morpholino RNA targets: evidence from the study of Danio rerio Ser/Arg-rich splicing factors using gene editing tools

We used morpholinos and gene editing tools to inactivate the srsf5a gene. In contrast to srsf5a homozygous mutants that did not display any phenotypic traits, microinjection of sMOsrsf5a led to developmental defects. By using RNA sequencing on morphants and control embryos we were able to identify a plethora of morpholino inadvertant target. Two biological replicates were used per conditions. Samples named CtrlMO consist in embryos injected with the control morpholino (5'-CCTCTTACCTCAGTTACAATTTATA-3', Gene Tools). Samples named sMOsrsf5a consist in embryos injected with the morpholino against srsf5a (5'-GGATTCAGTCTCACCTCTCACTGCA-3', Gene Tools).