Publications

factors determining the frequency of the killer trait within populations of the paramecium aurelia complex.	the factors maintaining the cytoplasmically inherited killer trait in populations of paramecium tetraurelia and paramecium biaurelia were examined using, in part, computer simulation. frequency of the k and k alleles, infection and loss of the endosymbionts, recombination during conjugation and autogamy, cytoplasmic exchange and natural selection were incorporated in a model. infection during cytoplasmic exchange at conjugation and natural selection were factors that would increase the proportio ...	1987	3557112
species of the paramecium aurelia complex in the middle sudeten of czecho-slovakia.	on the investigated territory three species of the complex were identified, namely paramecium biaurelia, p. triaurelia, and p. novaurelia. p. novaurelia dominated over the other species with regard to the number of clones established from nature as well as to habitats.	1992	1306505
effect of paramecium biaurelia cytoplasm transplantation on the duration of the interautogamous interval (iai) in paramecium tetraurelia.	the cytoplasm of paramecium biaurelia in various stages of iai was transplanted to paramecium tetraurelia cells of the same clonal age. such donor cytoplasm was effective in retardation of the expression of autogamy in the recipient clones. the results suggest that the cytoplasm of paramecium biaurelia may contain the autogamous immaturity factor whose level changes during the run of iai and whose specificity is the same as in paramecium tetraurelia.	1994	7982503
graviresponses in paramecium biaurelia under different accelerations: studies on the ground and in space	behavioural responses to different accelerations below 1 g and up to 5 g were investigated in paramecium biaurelia by using a centrifuge microscope on earth and in space during a recent space flight. increased stimulation (hypergravity) enhanced the negative gravitactic and the gravikinetic responses in paramecium biaurelia within seconds. cells did not adapt to altered gravitational conditions. repetitive stimulation did not change the graviresponses. the minimum acceleration found to induce gr ...	1996	9320113
graviresponses in paramecium biaurelia under different accelerations: studies on the ground and in space.	behavioural responses to different accelerations below 1 g and up to 5 g were investigated in paramecium biaurelia by using a centrifuge microscope on earth and in space during a recent space flight. increased stimulation (hypergravity) enhanced the negative gravitactic and the gravikinetic responses in paramecium biaurelia within seconds. cells did not adapt to altered gravitational conditions. repetitive stimulation did not change the graviresponses. the minimum acceleration found to induce gr ...	1996	11541118
influence of extremely low frequency electromagnetic fields on the swimming behavior of ciliates.	different species of ciliates (paramecium biaurelia, loxodes striatus, tetrahymena thermophila) have been taken as model systems to study the effects of extremely low-frequency electromagnetic fields (50 hz, 0.5-2.0 mt) on the cellular level. a dose-dependent increase in the mean swimming velocity and a decrease in the linearity of cell tracks were observed in all wild-type cells. in contrast, field-exposure did not increase the number of directional turns of the paramecium tetraurelia pawn muta ...	1997	9338630
comparative studies of the graviresponses of paramecium and loxodes.	gravitactic protozoa offer advantages in studying how the gravity stimulus is perceived on the cellular level. by means of a slow rotating centrifuge microscope in space the acceleration thresholds for gravitaxis of loxodes striatus and paramecium biaurelia were determined: < or = 0.15 x g for loxodes and 0.3 x g for paramecium, indicating different sensitivities of these species. neutral-buoyant densities of immobilized cells were determined using media of different densities, revealing densiti ...	1998	11541383
paramecium aurelia species complex in the river raba (southern poland).	this report reveals a significant acidity of the river raba at all the investigated sampling points, and rather poor differentiation of the zooplanktonic organisms. at one sampling point the presence of paramecium biaurelia was registered.	2000	11080918
the paramecium aurelia species complex in ukraine.	new habitats of paramecium biaurelia were found in the gorgany mts, eastern carpathians.	2001	11987461
habitat of paramecium biaurelia in italy, the island of elba.	the new habitat of paramecium biaurelia was found on the island elba.	2001	11732160
paramecium biaurelia--relation of strains.	inter- and intra-strain crosses were made in paramecium biaurelia of the p. aurelia species complex for studying the relation of strains within the species. altogether ten strains originating from scotland, spain, romania, czech republic, ukraine, italy, germany, russia, and poland (two strains) were studied. a high percentage of surviving clones in both generations, f1 (obtained by conjugation) and f2 (obtained by autogamy), was observed in strain crosses, indicating a strong relation between t ...	2002	12597536
variable acceleration influences cyclic amp levels in paramecium biaurelia.	paramecium is used as a model system to analyse the gravity signal transduction pathway, that leads to gravitaxis and gravikinesis. in order to prove whether gravistimulation is coupled with second messenger production (cyclic amp: hyperpolarization, cyclic gmp: depolarization) paramecium was fixated under variable accelerations (1 x g, 9 x g and 10(-4) x g) on a centrifuge and during a sounding rocket flight (texus 39). the analysis of camp and cgmp levels revealed an acceleration-dependent cha ...	2002	15002574
graviresponses of paramecium biaurelia during parabolic flights.	the thresholds of graviorientation and gravikinesis in paramecium biaurelia were investigated during the 5th dlr (german aerospace center) parabolic-flight campaign at bordeaux in june 2003. parabolic flights are a useful tool for the investigation of swimming behaviour in protists at different accelerations. at normal gravity (1 g) and hypergravity (1 g to 1.8 g), precision of orientation and locomotion rates depend linearly on the applied acceleration as seen in earlier centrifuge experiments. ...	2006	17180491
species of the paramecium aurelia complex in russia: new stands and overall distribution.	new stands of paramecium biaurelia, p. triaurelia, p. tetraurelia, p. pentaurelia, p. novaurelia, and p. dodecaurelia were recorded in russia. especially interesting is the record of p. novaurelia in vladivostok, russian far east, as it is a very rare species outside of europe. the distribution of species of the paramecium aurelia complex in eurasia with emphasis on findings in russia is discussed.	2010	20420199
impact of a high magnetic field on the orientation of gravitactic unicellular organisms--a critical consideration about the application of magnetic fields to mimic functional weightlessness.	the gravity-dependent behavior of paramecium biaurelia and euglena gracilis have previously been studied on ground and in real microgravity. to validate whether high magnetic field exposure indeed provides a ground-based facility to mimic functional weightlessness, as has been suggested earlier, both cell types were observed during exposure in a strong homogeneous magnetic field (up to 30 t) and a strong magnetic field gradient. while swimming, paramecium cells were aligned along the magnetic fi ...	2014	24621307
draft genome sequence of caedibacter varicaedens, a kappa killer endosymbiont bacterium of the ciliate paramecium biaurelia.	caedibacter varicaedens is a kappa killer endosymbiont bacterium of the ciliate paramecium biaurelia. here, we present the draft genome sequence of c. varicaedens.	2015	26543129
disentangling the taxonomy of rickettsiales and description of two novel symbionts ("candidatus bealeia paramacronuclearis" and "candidatus fokinia cryptica") sharing the cytoplasm of the ciliate protist paramecium biaurelia.	in the past 10 years, the number of endosymbionts described within the bacterial order rickettsiales has constantly grown. since 2006, 18 novel rickettsiales genera inhabiting protists, such as ciliates and amoebae, have been described. in this work, we characterize two novel bacterial endosymbionts from paramecium collected near bloomington, in. both endosymbiotic species inhabit the cytoplasm of the same host. the gram-negative bacterium "candidatus bealeia paramacronuclearis" occurs in clumps ...	2016	27742680
fitness impact of obligate intranuclear bacterial symbionts depends on host growth phase.	according to text book definition, parasites reduce the fitness of their hosts whereas mutualists provide benefits. but biotic and abiotic factors influence symbiotic interactions, thus under certain circumstances parasites can provide benefits and mutualists can harm their host. here we addressed the question which intrinsic biotic factors shape a symbiosis and are crucial for the outcome of the interaction between the obligate intranuclear bacterium holospora caryophila (alphaproteobacteria; r ...	2016	28066397