Open AccessWound-induced polyploidization is driven by Myc and supports tissue repair in the presence of DNA damage
Author(s) -
Janelle Grendler,
Sara Lowgren,
Monique Mills,
Vicki P. Losick
Publication year - 2019
Publication title -
development
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.754
H-Index - 325
eISSN - 1477-9129
pISSN - 0950-1991
DOI - 10.1242/dev.173005
Subject(s) - biology , mitosis , endoreduplication , microbiology and biotechnology , cell division , cell cycle , dna repair , cell , genetics , gene
Tissue repair usually requires either polyploid cell growth or cell division, but the molecular mechanism promoting polyploidy and limiting cell division remains poorly understood. Here, we find that injury to the adult Drosophila epithelium causes cells to enter the endocycle through the activation of Yorkie-dependent genes ( Myc and E2f1 ). Myc is even sufficient to induce the endocycle in the uninjured post-mitotic epithelium. As result, epithelial cells enter S phase but mitosis is blocked by inhibition of mitotic gene expression. The mitotic cell cycle program can be activated by simultaneously expressing the Cdc25-like phosphatase String ( stg ), while genetically depleting APC/C E3 ligase fizzy-related ( fzr ) . However, forcing cells to undergo mitosis is detrimental to wound repair as the adult fly epithelium accumulates DNA damage, and mitotic errors ensue when cells are forced to proliferate. In conclusion, we find that wound-induced polyploidization enables tissue repair when cell division is not a viable option.