title: N-methyl-N'-nitro-N-nitrosoguanidine and UV induced mutants of the dinoflagellate Crypthecodinium cohnii.
abstract: Mutant strains were chemically induced by treatment with N-methyl-N'-nitro-N-nitrosoguanidine (NTG) and UV irradiation. UV and NTG mutation rates were obtained that were both consistent with the organism being haploid. Three types of mutants were produced: (a) strains deficient in both beta- and gamma-carotene, the only carotenoids found in the wild type; phenotypes include albinos (translucent, dull white, "snow white") and cream-colored on agar as compared to the yellow-orange color of wild type colonies; (b) strains requiring adenine, guanine or cytosine in addition to the minimal medium for growth; (c) mutants that grow at a rate less than 40% of the wild type in minimal medium.
mesh_terms: D000818:Animals; D002338:Carotenoids / Q000096:biosynthesis; D004141:Dinoflagellida / Q000187:drug effects / Q000378:metabolism / Q000528:radiation effects; D056890:Eukaryota / Q000187:drug effects; D008769:Methylnitronitrosoguanidine / Q000494:pharmacology*; D009154:Mutation; D014466:Ultraviolet Rays
chemical_list: D008769:Methylnitronitrosoguanidine; D002338:Carotenoids