CC BY
18
18 • "PROTIST—2016
THE STABILITY OF THE MARINE CILIATE COMMUNITY TO ENVIRONMENTAL CHANGES
Esaulov A.S.1, Mazei Yu.A.12, Burkovsky I.V.2
1 - Penza State University
2 - Lomonosov Moscow State University [email protected]
A complete study of processes that occur during the formation of marine communities and their stability to factors of the environment requires information for a sufficient period of time that would cover a succession of many hundreds or even thousands of generations of organisms. Studies like these have been conducted by a team of biologists at the White Sea for a several decades. In field experiments on the transplantation of fragments of natural communities of marine ciliates into an estuary, restoration of the initial or modified species structure was observed after a short period of adaptation of the organisms. Their responses to new conditions included both species-specific reactions and group reactions (the synergistic effect). In a group, species are able to sustain larger amplitudes of variations in environmental factors than if they were separate and they can even occupy extreme biotopes. Under the conditions of the experiment, as well as in nature, a multitude of structural variants of the psammophile community (multivariability of structure) were created from the united pool of species through the recombination of their abundances. In total, the formation and maintenance of communities of unicellular organisms is determined by a complex mechanism that includes physiological (tolerance), population (reproductive properties), cenotic (interspecific interactions), and stochastic (reaction to environmental fluctuations) processes; their relative roles depend on the level of organization of the community (succession stage) and on the range of variations in environmental factors.
AGGREGATIVE BEHAVIOR, CELL SIGNALING AND MORPHOMETRICS IN ENTAMOEBA DISCRIMINATION STUDIES Espinosa A.12, Paz-y-Mino-C G.2, Hackey M.1, Rutherford S.3
1 - Department of Biology, Roger Williams University
2 - New England Center for the Public Understanding of Science, Roger Williams University
3 - Department of Environmental Science, Roger Williams University
Studies on clone- and kin-discrimination in protists have proliferated during the past decade. We report
clone-recognition experiments in seven Entamoeba lineages (E. invadens IP-1, E. invadens VK-1:NS, E. terrapinae, E. moshkovskii Laredo, E. moshkovskii Snake, E. histolytica HM-1:IMSS and E. dispar). We demonstrate that amebas themselves can discriminate self (clone) from different (themselves versus other clones). In mix-cell-line cultures between closely-related (E. invadens IP-1 versus E. invadens VK-1:NS) or distant-phylogenetic clones (E. terrapinae versus E. moshkovskii Laredo), amebas consistently aggregated with same-clone members. Additionally, we identified six putative cell-signals secreted by the amebas (RasGap/Ankyrin, coronin-WD40, actin, protein kinases, heat shock 70, and ubiquitin) and which known functions in Entamoeba spp. included: cell proliferation, cell adhesion, cell movement, and stress-induced encystation. Each clone was characterized morphometrically (length, width, and cell-surface area) and documented how they differed statistically from one another (as per single-variable or canonical-discriminant analyses). This is the first multi-clone characterization of Entamoeba spp. aggregative behavior, cell-signaling secretion, and morphometrics in the context of clone-recognition. Because unicellular eukaryotes belong to ancient and highly diverse phylogenetic lineages, occupy all environments on Earth, and participate in complex interactions with other organisms (as hosts, symbionts or parasites), they can be robust model systems to study the implications of taxa, clone and kin discrimination/recognition in ecological and evolutionary contexts, and with emphasis on basic or applied sciences.
DIVERSITY AND ABUNDANCE OF KINETO-PLASTIDS IN THE WORLD OCEAN Flegontova O.12, Flegontov P.32, Logacheva M.D.4, Konovalova O.P.4, Malviya S.5, Bowler C.5, Lukes J.126, Horâk A.12
1 - Faculty of Science, University of South Bohemia, Ceské Budëjovice, Czech Republic
2 - Institute of Parasitology, Biology Centre, Czech Academy of Sciences, Ceské Budëjovice, Czech Republic
3 - Faculty ofScience, University ofOstrava, Ostrava, Czech Republic
4 - Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow, Russia
5 - Ecole Normale Supérieure, PSL Research University, Institut de Biologie de l'Ecole Normale Supérieure (IBENS), Paris, France
6 - Canadian Institute for Advanced Research, Toronto, Canada
