CRISPR-Cas13d is a kind of smaller RNA-targeting nuclease. It shows an increasing
number of uses in RNA therapeutics and transcriptome engineering. However, its
main advantage over DNA-editing systems is its relatively low activity towards the
genome. This study therefore assessed the effectiveness of Cas13d for predicting offtarget
effects using modern machine learning tools to target of mammalian
transcriptome. The CRISPR-Cas13d guides RNAs (crRNAs) were design for the
Cas13d (RfxCas13d/CasRx) system with the intention of targeting the human
transcriptome. Thereafter, high-throughput cellular assessments were done to
measure the performance of the cells and their viability. The data was used to both
construct and verify machine learning models, such as the CNN-based TIGER
predictor and DeepCas13, a hybrid CNN–RNN framework. We gauged crucial
quantitative indices, which included the AUC, sensitivity, accuracy, and specificity
parameters. The result of the prediction model was crosschecked for accuracy with
the experimental result, with the use of qRT-PCR technique. It was thereafter
compared with nonessential gene controls to reduce the false predictions. The
comparative analysis revealed a remarkable improvement in predictive power when
transitioning from an empirical rule-based model to a machine learning model. It was
observed that the DeepCas13 model outperformed the TIGER model. The former
recorded an AUC of ~0.90 and an accuracy of ~85%, while the latter had an AUC of
~0.82 and an accuracy of ~78%. Also, it improved interpretability by combining
sequence, structural, and contextual RNA characteristics than the TIGER model. The
ROC and radar curve analyses consistently demonstrated that advanced deep
learning frameworks reduced off-target errors while maintaining high sensitivity. We
used both CRISPR-Cas13d and modern deep learning models to predict the outcomes
of direct-to-edit editing in the gene sequence. Hence, modern machine learning tools,
especially DeepCas13, have shown promising prospective in the development of
RNA therapeutics for research and clinical applications by proffering solutions to the
limitations that come with using computational approaches in CRISPR-Cas13d
research.
Keywords: CRISPR-Cas13d, RNA editing, transcriptome, off-target prediction, deep
learning
