%0 Journal Article %T Tolerance of Colpoda cucullus Nag-1 Resting Cysts and Presumed Structure for Protection against UV Light %A Yamane, Shinji %A Watanabe, Maho %A Funadani, Ryoji %A Miyazaki, Ryutaro %A Hasegawa, Yuya %A Arikawa, Mikihiko %A Suizu, Futoshi %A Matsuoka, Kou %A Matsuoka, Tatsuomi %J Acta Protozoologica %V 2020 %R 10.4467/16890027AP.20.004.12160 %N Volume 59, Issue 1 %P 55-60 %K cyst wall, endocyst layer, nuclei-surrounding particles, UV resistance %@ 0065-1583 %D 2020 %U https://ejournals.eu/en/journal/acta-protozoologica/article/tolerance-of-colpoda-cucullus-nag-1-resting-cysts-and-presumed-structure-for-protection-against-uv-light %X Resting cysts of the terrestrial ciliate Colpoda cucullus (Nag-1 strain) are highly resistant to UV light. It has been speculated that auto-fluorescent (blue fluorescent) particles surrounding the nuclei and yellowish fluorescent layers of the cyst wall are the candidate structures for the protection of the cellular components from UV light. The UV resistance of encysting cells was quickly acquired up to 5 h after the onset of encystment induction, and then gradually increased for several days. The less fluorescent ectocyst layer, yellowish fluorescent first-synthesized endocyst layer (en-1) and the NSPs were formed within 5 h after the onset of encystment induction, and thereafter endocyst layers became gradually thicker for several days. The cyst wall sample (ectocyst and endocyst layers) markedly absorbed a broad range of UV light. This result indicates that the cyst wall evidently has UV-cut function. These results support that the cyst wall and NSPs of C. cucullus play a role in the shielding of the cell components from UV light.