title: Differences in pigmentation between life cycle stages in Scrippsiella lachrymosa (dinophyceae).
abstract: Various life cycle stages of cyst-producing dinoflagellates often appear differently colored under the microscope; gametes appear paler while zygotes are darker in comparison to vegetative cells. To compare physiological and photochemical competency, the pigment composition of discrete life cycle stages was determined for the common resting cyst-producing dinoflagellate Scrippsiella lachrymosa. Vegetative cells had the highest cellular pigment content (25.2 ± 0.5 pg · cell(-1) ), whereas gamete pigment content was 22% lower. The pigment content of zygotes was 82% lower than vegetative cells, even though they appeared darker under the microscope. Zygotes of S. lachrymosa contained significantly higher cellular concentrations of β-carotene (0.65 ± 0.15 pg · cell(-1) ) than all other life stages. Photoprotective pigments and the de-epoxidation ratio of xanthophylls-cycle pigments in S. lachrymosa were significantly elevated in zygotes and cysts compared to other stages. This suggests a role for accessory pigments in combating intracellular oxidative stress during sexual reproduction or encystment. Resting cysts contained some pigments even though chloroplasts were not visible, suggesting that the brightly colored accumulation body contained photosynthetic pigments. The differences in pigmentation between life stages have implications for interpretation of pigment data from field samples when sampled during dinoflagellate blooms.
authors.affiliation: Department of Biological and Environmental Sciences, Göteborg University, Box 461, Göteborg, SE-405 30, Sweden.
authors.forename: Agneta
authors.initials: A
authors.lastname: Persson
authors.affiliation: National Oceanic and Atmospheric Administration, National Marine Fisheries Service, Northeast Fisheries Science Center, Milford Laboratory, 212 Rogers Avenue, Milford, Connecticut, 06460, USA.
authors.forename: Barry C
authors.initials: BC
authors.lastname: Smith
authors.affiliation: Hollings Marine Laboratory, College of Charleston, 331 Fort Johnson Rd, Charleston, South Carolina, 29412, USA.
authors.forename: Tyler
authors.initials: T
authors.lastname: Cyronak
authors.affiliation: Hollings Marine Laboratory, College of Charleston, 331 Fort Johnson Rd, Charleston, South Carolina, 29412, USA.
authors.forename: Emily
authors.initials: E
authors.lastname: Cooper
authors.affiliation: Hollings Marine Laboratory, College of Charleston, 331 Fort Johnson Rd, Charleston, South Carolina, 29412, USA.
authors.forename: Giacomo R
authors.initials: GR
authors.lastname: DiTullio
mesh_terms: D002734:Chlorophyll / Q000378:metabolism; D004141:Dinoflagellida / Q000166:cytology / Q000254:growth & development / Q000502:physiology*; D008018:Life Cycle Stages; D018384:Oxidative Stress; D010788:Photosynthesis / Q000502:physiology; D010858:Pigmentation / Q000502:physiology*; D024341:Xanthophylls / Q000378:metabolism; D015053:Zygote; D019207:beta Carotene / Q000378:metabolism
chemical_list: D024341:Xanthophylls; D019207:beta Carotene; D002734:Chlorophyll; C033808:diadinoxanthin; C103105:diatoxanthin
keywords: Scrippsiella lachrymosa; accumulation body; dinoflagellate; gamete; life stage; pellicle cyst; pigment; resting cyst; zygote