Photosynthesis uses light as a source of energy but its excess can result in production of harmful oxygen radicals. To avoid any resulting damage, phototrophic organisms can employ a process known as non-photochemical quenching (NPQ), where excess light energy is safely dissipated as heat. The mechanism(s) of NPQ vary among different phototrophs. Here, we describe a new type of NPQ in the organ...

The marine mixotrophic ciliate Mesodinium rubrum is known to acquire chloroplasts, mitochondria, nucleomorphs, and nucleus from its cryptophyte prey, particularly from species in the genera, Geminigera and Teleaulax. The sequestered prey nucleus and chloroplasts are considered to support photosynthesis of M. rubrum. In addition, recent studies have shown enlargement of the retained prey nucleus...

Cryptophytes are photosynthetic protists that have acquired their plastids through the secondary symbiotic uptake of a red alga. A remarkable feature of cryptophytes is that they maintain a reduced form of the red algal nucleus, the nucleomorph, between the second and third plastid membranes (periplastidial compartment; PC). The nucleomorph is thought to be a transition state in the evolution o...

sorkhankol wildlife refuge with an area of 1209 ha is located in the central part of anzali wetland. in total, 81 species belonging to 35 families and 68 genera were surveyed and identified on the basis of a floristic study from july 2013 through june 2014. the largest families are poaceae (11 taxa), asteraceae (8 taxa) apiaceae, brassicaceae and cyperacae (5 taxa). the dominant life forms were...

Lake Kislo-Sladkoe is a stratified water body partly isolated from the White Sea. Perennial meromixis in lake irregularly alternates with mixing events. Taking into account that protists of Arctic coastal bodies are understudied, we evaluated for first time vertical structure, species richness, and diversity assigned to different taxonomic groups using light, luminescent, scanning electron micr...

Kleptoplastidic, or chloroplast‐stealing, lineages offer insight into the process of acquiring photosynthesis. By quantifying ability these organisms to retain and use photosynthetic machinery from their prey, we can understand how intermediaries on endosymbiosis pathway might have evolved regulatory maintenance mechanisms. Here, focus a mixotrophic kleptoplastidic ciliate, Mesodinium chamaeleo...