Toti: An integrated multi-omics database to decipher the epigenetic regulation of gene expression in totipotent stem cells.

Totipotent stem cells (TSCs), the origin of mammalian life and the foundation of early embryogenesis, possess the highest differentiation capacity and extensive developmental potential. However, none of the existing embryonic databases have provided epigenetic and transcriptomic resources on totipotency, greatly limiting our understanding of its establishment and exit mechanisms. Here, we present Toti, a pioneering multi-omics database developed to investigate transcriptional and epigenetic factors governing totipotency, encompassing in vivo, in vitro, and genome-edited human and mouse embryonic TSCs, TSC-like cells, pluripotent stem cells, and embryos spanning preimplantation stages, with a total of 8,284 samples. Toti enables flexible keyword-based search, comparative visualization of transcriptomic and epigenetic features, motif and pathway enrichment analysis across diverse cell types, and single-cell resolution investigation of totipotency by offering Search, Browse, and Analysis modules, available at http://toti.zju.edu.cn/. Toti thus serves as a valuable resource for exploring the molecular underpinnings of totipotency.