Extending scope and power of circular RNA researchwith circtools 2.0

Circular RNAs (circRNAs) play a pivotal role in gene regulation, acting as transcriptional modulators at various cellular levels and exhibit remarkable specificity across cell types and developmental stages. Detecting circRNAs from high-throughput RNA-seq data presents significant challenges, as it requires specialized tools to identify back-splice junctions (BSJ) in raw sequencing data. To address this need, we previously developed circtools, a robust and user-friendly software for circRNA detection, downstream analysis, and wet-lab integration. Building on this foundation, we now introduce circtools 2.0, a significantly enhanced framework designed to advance computational and support experimental analysis for circular RNA research. Novel key features of circtools 2.0 include: (1) an ensemble approach to circRNA detection with improved recall rates, (2) a module for automated design of circRNA padlock probes for the Xenium spatial trancriptomics platform, (3) circRNA conservation analysis across animal model species, and (4) support for the Oxford Nanopore sequencing platform for full-length circRNA detection. Availabilitycirctools 2.0 is available at github.com/jakobilab/circtools and licensed under GPLv3.0. Contacttjakobi@arizona.edu