Premium
Targeted Inactivation of DNA Photolyase Genes in Medaka Fish ( Oryzias latipes )
Author(s) -
IshikawaFujiwara Tomoko,
Shiraishi Eri,
Fujikawa Yoshihiro,
Mori Toshio,
Tsujimura Tohru,
Todo Takeshi
Publication year - 2016
Publication title -
photochemistry and photobiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.818
H-Index - 131
eISSN - 1751-1097
pISSN - 0031-8655
DOI - 10.1111/php.12658
Subject(s) - photolyase , cryptochrome , pyrimidine dimer , dna repair , biology , oryzias , mutant , nucleotide excision repair , dna , gene , microbiology and biotechnology , genetics , circadian clock
Proteins of the cryptochrome/photolyase family ( CPF ) exhibit sequence and structural conservation, but their functions are divergent. Photolyase is a DNA repair enzyme that catalyzes the light‐dependent repair of ultraviolet ( UV )‐induced photoproducts, whereas cryptochrome acts as a photoreceptor or circadian clock protein. Two types of DNA photolyase exist: CPD photolyase, which repairs cyclobutane pyrimidine dimers ( CPD s), and 6‐4 photolyase, which repairs 6‐4 pyrimidine–pyrimidone photoproducts (6‐4PPs). Although the Cry‐DASH protein is classified as a cryptochrome, it also has light‐dependent DNA repair activity. To determine the significance of the three light‐dependent repair enzymes in recovering from solar UV‐induced DNA damage at the organismal level, we generated mutants in each gene in medaka using the CRISPR genome editing technique. The light‐dependent repair activity of the mutants was examined in vitro in cultured cells and in vivo in skin tissue. Light‐dependent repair of CPD was lost in the CPD photolyase‐deficient mutant, whereas weak repair activity against 6‐4 PP s persisted in the 6‐4 photolyase‐deficient mutant. These results suggest the existence of a heretofore unknown 6‐4 PP repair pathway and thus improve our understanding of the mechanisms of defense against solar UV in vertebrates.