eccDNA Atlas: a comprehensive resource of eccDNA catalog

Abstract Extrachromosomal circular DNA (eccDNA) represents a large category of non-mitochondrial and non-plasmid circular extrachromosomal DNA, playing an indispensable role in various aspects such as tumorigenesis, immune responses. However, the information of characteristics and functions about eccDNA is fragmented, hiding behind abundant literatures and massive whole-genome sequencing (WGS) data, which has not been sufficiently used for the identification of eccDNAs. Therefore, establishing an integrated repository portal is essential for identifying and analyzing eccDNAs. Here, we developed eccDNA Atlas (http://lcbb.swjtu.edu.cn/eccDNAatlas), a user-friendly database of eccDNAs that aims to provide a high-quality and integrated resource for browsing, searching and analyzing eccDNAs from multiple species. eccDNA Atlas currently contains 629 987 eccDNAs and 8221 ecDNAs manually curated from literatures and 1105 ecDNAs predicted by AmpliconArchitect based on WGS data involved in 66 diseases, 57 tissues and 319 cell lines. The content of each eccDNA entry includes multiple aspects such as sequence, disease, function, characteristic, validation strategies. Furthermore, abundant annotations and analyzing utilities were provided to explore existing eccDNAs in eccDNA Atlas or user-defined eccDNAs including oncogenes, typical enhancers, super enhancers, CTCF-binding sites, SNPs, chromatin accessibility, eQTLs, gene expression, survival and genome visualization. Overall, eccDNA Atlas provides an integrated eccDNA data warehouse and serves as an important tool for future research.