Anhydrobiosis-associated nuclear DNA damage and repair in the Sleeping Chironomid; Linkage with radioresistance

Gusev, O.*; Nakahara, Yuichi*; Vanyagina, V.*; Malutina, L.*; Cornette, R.*; Sakashita, Tetsuya; Hamada, Nobuyuki*; Kikawada, Takahiro*; Kobayashi, Yasuhiko; Okuda, Takashi*

Anhydrobiotic chironomid larvae can withstand prolonged complete desiccation as well as other external stresses including ionizing radiation. To understand the cross-tolerance mechanism, we have analyzed the damage and repair in the nuclear DNA using DNA comet assays and gene expression in relation to anhydrobiosis and radiation. We found that dehydration causes alterations in chromatin structure and a severe fragmentation of nuclear DNA in the cells of the larvae despite successful anhydrobiosis. Furthermore, while the larvae have restored physiological activity within an hour following rehydration, nuclear DNA restoration typically took 72 to 96 h.