scEccDNAdb: an integrated single-cell eccDNA resource for human and mouse

Extrachromosomal circular DNA (eccDNA), an extrachromosomal circular structured DNA, is extensively found in eukaryotes. Exploring eccDNA at the single-cell level contributes to understanding heterogeneity, evolution, development, and specific functions within cells. Nevertheless, the high-throughput identification methods for single-cell eccDNA are complex, and currently mature and widely applicable technologies are lacking. Those factors have led to a scarcity of resources for studying eccDNA at the single-cell level. Therefore, using available single-cell whole-genome sequencing (WGS) data, we have constructed a comprehensive eccDNA database named scEccDNAdb ( https://lcbb.swjtu.edu.cn/scEccDNAdb/ ). Presently, scEccDNAdb comprises 3,195,464 single-cell eccDNA entries from both disease/health human and mouse samples, which provides comprehensive annotations including oncogenes, typical enhancers, super-enhancers, CTCF binding sites, SNPs, chromatin accessibility, eQTLs, transcription factor binding sites, motifs, and SVs. Additionally, it provides nine online analysis and visualization tools, facilitating the generation of publication-quality figures for eccDNA analysis through the upload of customized files. Overall, scEccDNAdb represents the first comprehensive database known to us for exploring and analyzing single-cell eccDNA data in diverse cell types, tissues, and species. Graphical abstract