%0 Journal Article %A Kazuhiro Murakami %A Yumi Terakado %A Kikue Saito %A Yoshie Jomen %A Haruna Takeda %A Masanobu Oshima %A Nick Barker %T Genome-Scale CRISPR Screening reveals novel factors regulating Wnt-dependent regeneration of mouse gastric organoids %D 2020 %R 10.1101/2020.07.17.208496 %J bioRxiv %P 2020.07.17.208496 %X An ability to safely harness the powerful regenerative potential of adult stem cells for clinical applications is critically dependent on a comprehensive understanding of the underlying mechanisms regulating their activity. Epithelial organoid cultures accurately recapitulate many features of in vivo stem cell-driven epithelial regeneration, providing an excellent ex vivo platform for interrogation of key regulatory mechanisms. Here, we employed a Genome-Scale CRISPR Knock-Out (GeCKO) screening assay using mouse gastric epithelial organoids to identify novel modulators of Wnt-driven stem cell-dependent epithelial regeneration in the gastric mucosa. In addition to known Wnt pathway regulators such as Apc, we found that knock-out (KO) of Alk, Bclaf3 or Prkra supports the Wnt independent self-renewal of gastric epithelial cells ex vivo. In adult mice, expression of these factors is predominantly restricted to non Lgr5-expressing stem cell zones above the gland base, implicating a critical role for these factors in suppressing Wnt-dependent self-renewal of gastric epithelia. Furthermore, using comprehensive RNA-sequencing analysis, we found that these factors influence epithelial regeneration by regulating Wnt signalling, apoptosis and expression of Reg family genes which could contribute to the epithelial regeneration through JAK/STAT3 pathway.Competing Interest StatementThe authors have declared no competing interest. %U https://www.biorxiv.org/content/biorxiv/early/2020/07/17/2020.07.17.208496.full.pdf