2,984 research outputs found
Molecular characterization of the obligate endosymbiont "Caedibacter macronucleorum" Fokin and Gortz, 1993 and of its host Paramecium duboscqui strain Ku4-8
No full textAbstract: Bacterial endosymbionts of protozoa were often described as new species by protozoologists mainly on the basis of few morphological characters and partly by host specificity. Many of these species have never been validated by prokaryotic microbiologists whose taxonomic rules are quite different from those of protozoologists, who use the Zoological Code of Nomenclature. "Caedibacter macronucleorum" Fokin and Gortz 1993, an endosymbiont of Paramecium duboscqui, belongs to this category. Here we provide the molecular characterization of this organism and of its host P. duboscqui strain Ku4-8. Bacterial 16S rRNA gene sequence analysis proved that "C. macronucleorum" belongs to the Alphaproteobacteria. It is closely related to Caedibacter caryophilus but not to Caedibacter taeniospiralis, which belongs to the Gammaproteobacteria. "Caedibacter macronucleorum" and C. caryophilus 16S rRNA genes show a similarity value of 99%. This high 16S rRNA sequence similarity and the lack of ..
Investigations on the species of the Paramecium aurelia complex (Ciliophora, Protista) in Israel
No full textNo abstract availabl
Rediscovery and characterisation of Frontonia fusca (Quennerstedt, 1869) Kahl, 1931(Ciliophora, Peniculia).
No full textFrontonia fusca (QUENNERSTEDT, 1869) KAHL, 1931 was rediscovered from brackish water bodies with a salinity range
of 4–25 ‰ on the Tyrrhenian and Ligurian coastlines (Mediterranean Sea) at Naples and in Tuscany, Italy. From the morphological
point of view it is a typical member of this genus; it is about 100–170 μm long in vivo and has two contractile vacuoles
with 6–9 collecting canals and 2–3 excretory pores, and two small micronuclei of the “endosomal” type. A very distinctive pigment
spot on the right side of the anterior dorsal cortex is always presented. The dark-greenish pigment of the organelle has no
autofluorescence and is located in small vacuoles 0.5–1.2 μm across and equally distributed during cell division between dividers
within 45–60 min, again producing a spot in the same location of daughter cells. The ciliate is positive phototactic. Frontonia fusca
has a strong food preference to diatoms and can easily survive in pure marine water, but not in non-saline one. Till now the
species was found in Europe only. The general morphology and morphometry is redescribed according to observations of living
and silver-impregnated cells. The population from the Tyrrhenian Sea is fixed as neotype. According to 18S rRNA molecular data,
Frontonia fusca clusters with some other brackish water frontoniids, which clearly separate from the other representatives of
the genus
Life of Alexander Onufrievich Kowalevsky (1840 – 1901).
No full textA short description of the life of the famous
Russian embryologist and zoologist AlexanderO. Kowalevsky
is presented, including some rare photos of the scientist
Paramecium genus: biodiversity, some morphological features and the key to the main morphospecies discrimination.
No full textBiodiversity of the genus Paramecium and its worldwide distribution are discussed.
A simple and reliable way of species discrimination based on variation in the
morphology of micronuclei and contractile vacuoles is presented
[At the background of ecological parasitology]
No full textThe data on scientific and teaching activities of A. A. Filipchenko, doctor of medicine and scientist-parasitologist, one of the founders of ecological parasitology in Russia is presented in this article. His fate and participation in the formation of this biological discipline were concealed for a long time. One of the reasons for this situation is the destruction of the scientist in 1938 during the course of mass repressions performed by Soviet State against its own citizens
Otto Bütschli (1848-1920). Where we will genuflect?
No full textThe article’s subject is the life story of Prof. Bütschli and his main achievements in
Protozoology and Cytology as well as his relationship with Russian scientists. For
the first time the unknown history of his grave and the grave monument are revealed.
It has been found out that the grave is located in Karlsruhe but not in Heidelberg,
as thought earlier, where the scientist spent 42 most productive years of his life. The
article is illustrated with several unique photos
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