ANALYSIS OF ULTRAVIOLET RADIATION-INDUCED DNA DAMAGE AND THE PRESENCE OF MYCOSPROINE-LIKE AMINO ACIDS (MAAs) IN THE SEA ANEMONE AIPTASIA .PALLIDA

Abstract

Ultraviolet radiation (UVR) is a commonly occurring genotoxin in tropical marine environments. While shallow-water organisms have a variety of defenses against UVR, DNA damage can still occur. documented the extent of DNA damage and subsequent repair response in the sea anemone Aiptasia pallida under both laboratory and field conditions. In addition the presence of specific biological UVR sunscreens, mycosporine-like amino acids (MAAS) was determined. Cultured A. pallida and freshly collected field anemones from Walsingham Pond, Bermuda were examined for the presence of MAAs. In addition, an experiment was carried out to determine their efficiency to repair DNA damage incurred in cultured aposymbiotic anemones and field-collected animals when exposed to UVR using the comet assay. It was found that field anemones produce relatively large quantities of MAAs and efficiently repaired DNA damage incurred from a reduced level of natural UVR. Clonal aposymbiotic anemones produced much smaller quantities of MAAs than either the field-collected anemones or cultured symbiotic animals. In addition, aposymbionts appeared to less efficiently repair DNA damage under laboratory conditions than field-collected symbiotic counterparts. In the presence of photosynthetically available radiation (PAR), results presented here suggest that clonal aposymbionts maybe capable of producing the enzyme photolyase, which is responsible for the reactivation of UV-induced photoproducts. Results presented here suggest that the ability of A. pallida to repair DNA damage and/or protect themselves from the detrimental effects of UVR may be an important factor for their survival.