Abstract:
:Haploid micronuclei produced by meiosis in Paramecium caudatum are destined either to survive or to degenerate depending upon their position in the cytoplasm. The behavior of the four meiotic division products in living cells and their DNA synthesis patterns were examined to determine whether there were differences between nuclei destined to survive and those destined for degeneration. Some prospective degenerating nuclei divided, as did the surviving nuclei, but then became pycnotic immediately after division. This indicates that division and pycnosis are not alternative nuclear fates, but are independent processes. Microspectrophotometric measurements of DNA content showed that each meiotic product had 1 C amount of DNA at the second meiotic telophase and then increased the amount to 2 C linearly with time after the telophase. The time course of the DNA synthesis in the prospective degenerating nuclei was not different from that in the surviving ones. These results suggest that the determination of survival or degeneration of meiotic products is a process independent of division and DNA replication. But spindles and daughter nuclei of prospective degenerating nuclei showed some morphological differences from those of surviving ones. Furthermore, the degenerating nuclei became indistinct and small at the beginning of the degeneration, whereas this change was not observed in the surviving ones. Most of the surviving nuclei were surrounded by a clear region of the cytoplasm before their division. These morphological differences between the prospective surviving and degenerating nuclei may be related to their eventual outcomes.
journal_name
Eur J Protistoljournal_title
European journal of protistologyauthors
Yanagi Adoi
10.1016/S0932-4739(11)80317-2subject
Has Abstractpub_date
1992-02-21 00:00:00pages
37-42issue
1eissn
0932-4739issn
1618-0429pii
S0932-4739(11)80317-2journal_volume
28pub_type
杂志文章abstract::Expression of surface antigens is usually mutually exclusive, meaning that only one protein is present on the cell surface. With the RNAi feeding technology we induce serotype shifts in Paramecium tetraurelia which are demonstrated to be incomplete, meaning that the cells remain in a shifting state. The coexpression o...
journal_title:European journal of protistology
pub_type: 杂志文章
doi:10.1016/j.ejop.2005.09.003
更新日期:2006-03-01 00:00:00
abstract::Ookinetes of Leucocytozoon simondi have a Polar Ring Complex (PRC) which is composed of a stout electron-lucent polar ring with about 34 posteriorly extending tines. The latter are subtended by about 76 subpellicular microtubules. A broad collar of electron-dense material is associated with the cytoplasmic surface of ...
journal_title:European journal of protistology
pub_type: 杂志文章
doi:10.1016/S0932-4739(89)80061-6
更新日期:1989-04-14 00:00:00
abstract::Shifts in community composition of soil protozoa in response to climate change may substantially influence microbial activity and thereby decomposition processes. However, effects of climate and vegetation on soil protozoa remain poorly understood. We studied the distribution of soil testate amoebae in herbaceous and ...
journal_title:European journal of protistology
pub_type: 杂志文章
doi:10.1016/j.ejop.2012.08.004
更新日期:2013-05-01 00:00:00
abstract::The authors present light and electron microscopical data on a myxosporidian found in the gills of Crenicichla lepidota Heckel, 1840 (Teleostei, Cichlidae) from the Amazon river. Based on the spore morphology, it is concluded that this species belongs to the family Myxobolidae, genus Henneguya, and that it constitutes...
journal_title:European journal of protistology
pub_type: 杂志文章
doi:10.1016/S0932-4739(11)80233-6
更新日期:1992-08-21 00:00:00
abstract::The apostome ciliate Hyalophysa chattoni, a symbiont of the estuarine grass shrimp Palaemonetes pugio, was tested for its growth and reproductive ability in a wide range of salinities from 0.1 to 55 ppt. Shrimp, with their attached ciliates, were slowly acclimated to different salinities in order to assess protozoan c...
journal_title:European journal of protistology
pub_type: 杂志文章
doi:10.1016/j.ejop.2007.11.002
更新日期:2008-05-01 00:00:00
abstract::Cell division in Prorocentrum micans was studied with TEM, SEM and with fluorescence microscope techniques to visualize cytoskeletal structures. The cleavage furrow consists of the plasma membrane and two valvar vesicles. Its leading edge is lined with actin filaments. The completion of cytokinesis (like in some other...
journal_title:European journal of protistology
pub_type: 杂志文章
doi:10.1016/S0932-4739(11)80175-6
更新日期:1990-03-09 00:00:00
abstract::This review gives a brief report on some recent advances in the study of molecular biology of ciliate genes. The main emphasis will be put on those results which may contribute to a better understanding of how gene structure and genome organization has evolved in ciliates. New data will be discussed in relation to the...
journal_title:European journal of protistology
pub_type: 杂志文章
doi:10.1016/S0932-4739(11)80384-6
更新日期:1990-08-31 00:00:00
abstract::The morphology and infraciliature of two pleurostomatid ciliates, Amphileptus aeschtae nov. spec. and Amphileptus eigneri nov. spec., collected from shrimp-culturing ponds of the Bohai Sea, China, were investigated using live observations and the protargol impregnation method. The new species A. aeschtae is identified...
journal_title:European journal of protistology
pub_type: 杂志文章
doi:10.1016/j.ejop.2006.10.002
更新日期:2007-06-01 00:00:00
abstract::Since its description 35 years ago from Quebec, Canada, the poorly known monospecific testate rhizopod genus Puytoracia (type species, Puytoracia bergeri) has been reported only from the Himalayan region of Nepal. This species was recently found at 13 locations in Ontario, Canada, and the range of form variation of th...
journal_title:European journal of protistology
pub_type: 杂志文章
doi:10.1016/j.ejop.2006.04.002
更新日期:2006-09-01 00:00:00
abstract::Cotterillia bromelicola nov. gen., nov. spec. was discovered in the tanks of the Mexican bromeliad Tillandsia heterophylla. Its morphology, ontogenesis, and 18S rDNA were studied with standard methods. Cotterillia has many cirral rows on both sides of the body. Uniquely, and thus used to diagnose the new genus Cotteri...
journal_title:European journal of protistology
pub_type: 杂志文章
doi:10.1016/j.ejop.2010.08.003
更新日期:2011-01-01 00:00:00
abstract::A strain of the free-living flagellate Dimastigella trypaniformis Sandon was isolated from the gut contents of the Australian termite Mastotermes darwiniensis Froggatt. The fine structure of the isolate (Ulm strain) was compared with a strain isolated from soil in Scotland (Glasgow strain). The biflagellated trophozoi...
journal_title:European journal of protistology
pub_type: 杂志文章
doi:10.1016/S0932-4739(11)80404-9
更新日期:1993-11-12 00:00:00
abstract::Two new marine scuticociliates, Sathrophilus planus n. sp. and Pseudoplatynematum dengi n. sp., isolated from coastal waters of Qingdao, northern China, were investigated using live observation and silver impregnations. Sathrophilus planus can be recognized by its elongate and conspicuously flattened body, ca. 16 soma...
journal_title:European journal of protistology
pub_type: 杂志文章
doi:10.1016/j.ejop.2010.03.002
更新日期:2010-08-01 00:00:00
abstract::Fine structure of the membrane system was examined in a large heliozoon, Echinosphaerium akamae, especially by means of negative staining and thin sectioning under the electron microscope. In addition to solitary membranous organelles such as mitochondrion, Golgi apparatus and nuclear envelope, there was found a conti...
journal_title:European journal of protistology
pub_type: 杂志文章
doi:10.1016/S0932-4739(89)80047-1
更新日期:1989-02-24 00:00:00
abstract::The present study was undertaken to describe Cryptosporidium spp. infection in tree squirrels from 17 locations in Northern Italy. A total of 357 squirrels were examined, including species native to Europe (Sciurus vulgaris; n=123), and species introduced from North America (Sciurus carolinensis; n=162) and Southeast ...
journal_title:European journal of protistology
pub_type: 杂志文章
doi:10.1016/j.ejop.2017.09.007
更新日期:2017-10-01 00:00:00
abstract::Vertical variations in trophic-functional patterns of biofilm-dwelling ciliates were studied in coastal waters of the Yellow Sea, northern China. A total of 50 species were identified and assigned to four trophic-functional groups (TFgrs): algivores (A), bacterivorous (B), non-selective (N) and raptors (R). The trophi...
journal_title:European journal of protistology
pub_type: 杂志文章
doi:10.1016/j.ejop.2018.01.003
更新日期:2018-04-01 00:00:00
abstract::Pterospora demodendrion sp.nov., an acephaline eugregarine (Eugregarinorida, Urosporidae) from the coelom of Axiothella mucosa (Polychaeta, Maldanidae) is described. The gamont averages 277 × 139 μm and possesses 20-36 posterior prolongations. Gametocysts average 412 × 287 μm; without polar funneled openings. Oocysts ...
journal_title:European journal of protistology
pub_type: 杂志文章
doi:10.1016/S0932-4739(11)80427-X
更新日期:1991-03-28 00:00:00
abstract::Dileptid and tracheliid ciliates have been traditionally classified within the subclass Haptoria of the class Litostomatea. However, their phylogenetic position among haptorians has been controversial and indicated that they may play a key role in understanding litostomatean evolution. In order to reconstruct the evol...
journal_title:European journal of protistology
pub_type: 杂志文章
doi:10.1016/j.ejop.2011.04.006
更新日期:2011-11-01 00:00:00
abstract::Acanthamoebae feed on bacteria but are also frequent hosts of bacterial symbionts. Here, we describe the stable co-occurrence of two symbionts, one affiliated to the genus Parachlamydia and the other to the candidate genus Paracaedibacter (Alphaproteobacteria), within a clinical isolate of Acanthamoeba hatchetti genot...
journal_title:European journal of protistology
pub_type: 杂志文章
doi:10.1016/j.ejop.2016.04.002
更新日期:2016-10-01 00:00:00
abstract::The free-living anaerobic flagellate Psalteriomonas vulgaris n. spec. is described. The organism has four flagella of equal length which arise immediately subapically to the anterior part of the cell, within the apex of the ventral groove. The ultrastructural organization of the mastigont system and the ventral groove...
journal_title:European journal of protistology
pub_type: 杂志文章
doi:10.1016/S0932-4739(11)80302-0
更新日期:1993-02-19 00:00:00
abstract::Human adenoviruses are responsible for a wide range of clinical infections and are present in aquatic environments, including river, seawater, drinking-water and sewage. Free-living amoebae (Acanthamoeba) in the same environments may internalize them and other microorganisms can act as a reservoir for the internalized...
journal_title:European journal of protistology
pub_type: 杂志文章
doi:10.1016/j.ejop.2016.02.006
更新日期:2016-06-01 00:00:00
abstract::We report the use of nile red as a rapid and inexpensive method to estimate cellular lipids in three species of Paramecium and in Tetrahymena by the direct application of the dye to living or fixed cells without extraction and purification. Qualitative estimates of the relative changes in the lipid content of cells of...
journal_title:European journal of protistology
pub_type: 杂志文章
doi:10.1016/S0932-4739(11)80129-X
更新日期:1990-06-29 00:00:00
abstract::A new species of unicellular opisthokont protist, Nuclearia thermophila sp. nov., was isolated from the warm spring water of Yunoko Lake, Japan, and has been described using light and electron microscopy. It exists as a spherical floating form and a flattened amoeboid form showing various shapes. The cells occasionall...
journal_title:European journal of protistology
pub_type: 杂志文章
doi:10.1016/j.ejop.2008.09.004
更新日期:2009-05-01 00:00:00
abstract::Protistan parasites have an undisputed global health impact. However, outside of a few key exceptions, e.g. the agent of malaria, most of these infectious agents are neglected as important health threats. The Symposium entitled "Free-living amoebae and neglected pathogenic protozoa: health emergency signals?" held at ...
journal_title:European journal of protistology
pub_type: 杂志文章
doi:10.1016/j.ejop.2020.125760
更新日期:2020-11-28 00:00:00
abstract::A new Naegleria species, N. andersoni, is described that occurs world-wide. The new species consists of two subspecies and can be distinguished from previously described species on the basis of antigenic, isoenzyme and restriction enzyme DNA fragment differences and in maximum growth temperature tolerated. N. anderson...
journal_title:European journal of protistology
pub_type: 杂志文章
doi:10.1016/S0932-4739(88)80022-1
更新日期:1988-10-01 00:00:00
abstract::Species in the genera Hexasterias and Halodinium have been recorded over the last decades as acritarchs in palynological and/or plankton studies. In paleoenvironmental studies, these resting stages are often interpreted as indicators of freshwater input. The biological affinity of these genera has never been definitel...
journal_title:European journal of protistology
pub_type: 杂志文章
doi:10.1016/j.ejop.2018.09.002
更新日期:2018-10-01 00:00:00
abstract::The species Leptomyxa flabellata was described by Goodey in 1915 and re-isolated by Pussard and Pons in 1976. It seems that it was never seen (or never recognized) again since that time. The strain designated as "Leptomyxa flabellata CCAP 1546/2" was studied by Cann in 1984, however the quality of the electron microsc...
journal_title:European journal of protistology
pub_type: 杂志文章
doi:10.1016/j.ejop.2017.12.001
更新日期:2018-02-01 00:00:00
abstract::The cortical morphogenesis of Amphisiella australis Blatterer and Foissner, 1988 was investigated using protargol impregnation. In 43% of the examined cells the morphogenesis starts with a dedifferentiation of the two transverse cirri forming the oral primordium. In the other specimens the oral primordium either origi...
journal_title:European journal of protistology
pub_type: 杂志文章
doi:10.1016/S0932-4739(11)80004-0
更新日期:1992-11-20 00:00:00
abstract::Toxoplasma gondii is a zoonotic parasite with a world-wide distribution. House mice (Mus musculus) play an important role as a reservoir host in the parasite life cycle. However, their detection in mouse brain is limited because the host potentially harbours only a few tissue cysts. In order to improve the diagnosis, ...
journal_title:European journal of protistology
pub_type: 杂志文章
doi:10.1016/j.ejop.2013.08.002
更新日期:2014-02-01 00:00:00
abstract::We observed reproductive swarmer cells of the nassellarian and spumellarian polycystine radiolarians Didymocyrtis ceratospyris, Pterocanium praetextum, Tetrapyle sp., and Triastrum aurivillii using light, scanning and transmission electron microscopy. The swarmer cells had subspherical to ovoid or spindle shapes with ...
journal_title:European journal of protistology
pub_type: 杂志文章
doi:10.1016/j.ejop.2016.02.007
更新日期:2016-06-01 00:00:00
abstract::Copidognathus nautilei Bartsch, 1997, from a hydrothermal vent field of the Mid-Atlantic Ridge at about 13 degrees N, 45 degrees W and 4090 m depth, was infested with the suctorian Corynophrya abyssalis n. sp., with up to 58 epizoans per mite. The new suctorian has a sacciform body with seven longitudinal ribs, a comp...
journal_title:European journal of protistology
pub_type: 杂志文章
doi:10.1016/j.ejop.2010.02.001
更新日期:2010-08-01 00:00:00