GLORIA

GEOMAR Library Ocean Research Information Access

feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 11
    Electronic Resource
    Electronic Resource
    Oxford, UK : Blackwell Publishing Ltd
    The @journal of eukaryotic microbiology 48 (2001), S. 0 
    ISSN: 1550-7408
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology
    Notes: . Large miliolid foraminifers of the subfamily Soritinae bear symbiotic dinoflagellates morphologically similar to the species of the “Symbiodinium” complex, commonly found in corals and other marine invertebrates. Soritid foraminifers are abundant in coral reefs and it has been proposed that they share their symbionts with other dinoflagellate-bearing reef dwellers. In order to test this hypothesis, we have analysed partial large subunit ribosomal DNA sequences from dinoflagellates symbionts obtained from 28 foraminiferal specimens, and compared them to the corresponding sequences of Symbiodinium-like endosymbionts from various groups of invertebrates. Phylogenetic analysis of our data shows that all soritid symbionts belong to the “Symbiodinium” species complex, within which they form seven different molecular types (Fr1–Fr7). Only one of these types (Fr1) branches within a group of invertebrate symbionts, previously described as type C. The remaining six types form sister groups to coral symbionts previously designed as types B, C, and D. Our data indicate a high genetic diversity and specificity of Symbiodinium-like symbionts in soritids. Except for type C, we have found no evidence for the transmission of symbionts between foraminifers and other symbiont-bearing invertebrates from the same localities. However, exchanges must have occurred frequently between the different species of Soritinae, as suggested by the lack of host specificity and some biogeographical patterns observed in symbiont distribution. Our data suggest that members of the subfamily Soritinae acquired their symbionts at least three times during their history, each acquisition being followed by a rapid diversification and independent radiation of symbionts within the foraminiferal hosts.
    Type of Medium: Electronic Resource
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 12
    Electronic Resource
    Electronic Resource
    Oxford, UK : Blackwell Publishing Ltd
    The @journal of eukaryotic microbiology 9 (1962), S. 0 
    ISSN: 1550-7408
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology
    Notes: SYNOPSIS. Several trichomonads from poikilotherms (Hypotrichomonas acosta, Monocercomonas colubrorum and M. sp., Trichomonas batrachorum, and Tritrichomonas augusta) grew in a nearly-defined medium to a level of 10–40% that permitted with media containing casein digests; T. augusta (4 strains) grew best. The defined medium contained TEM-4T (a semisynthetic fat based on beef-tallow fatty acids) and ascorbyl “palmitate” as sources of fatty acids. Besides ascorbyl palmitate, thiomalic and ascorbic acids, and tocopherol served as reducers and antiöxidants. High concentrations of nucleotides (adenylic, cytidylic, guanylic, and uridylic acids) seemed necessary. Indigo carmine was a useful redox indicator; the flagellates never grew in the oxidized zone. Extra trace elements and amino acids or rich natural media permitted better growth at about 34.5°C—the upper temperature limit for these trichomonads, raising the issue of a biochemical basis of a thermal barrier to the invasion of warmblooded hosts. Except for the limited carbohydrate in the nucleotides, carbohydrate could be omitted, the main substrates being a combination of glycerol, acetate, and gylcero-phosphate, posing the question of the identity of the anaerobic, presumably non-glycolytic, energy-yielding pathway.
    Type of Medium: Electronic Resource
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 13
    Electronic Resource
    Electronic Resource
    Oxford, UK : Blackwell Publishing Ltd
    The @journal of eukaryotic microbiology 32 (1985), S. 0 
    ISSN: 1550-7408
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology
    Notes: .Protozoa may be thought of as preadapted to serve as hosts for cellular endosymbionts by virtue of their widespread ability to take up particles by endocytosis. The absence of the cell wall so characteristic of plants and fungi and the commonly large size of most protozoa are additional factors favoring protozoan cells for endosymbioses. The conversion of symbiont into a cellular organelle (e.g. a mitochondrion or chloroplast) is more complicated, especially since the latter do not code for all of their own proteins. Thus, such conversions are held to be rare. Among protozoa, numerous foraminifera appear to have characteristics making them very favorable as hosts for certain algae. Such adaptations, both physiological and morphological in nature, are discussed. Also discussed in this paper are the ways by which (present-day) chloroplasts and mitochondria may have been derived from early endosymbionts: a single ancestral cyanobacterium, in the first case, and a single ancestral purple-nonsulfur bacterium, in the second. Mechanisms for insertion of proteins into and across the organellar membranes had to be evolved for all genes transferred from the symbionts into the host nucleus.
    Type of Medium: Electronic Resource
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 14
    Electronic Resource
    Electronic Resource
    Oxford, UK : Blackwell Publishing Ltd
    The @journal of eukaryotic microbiology 32 (1985), S. 0 
    ISSN: 1550-7408
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology
    Notes: Long neglected has been the extensive and more or less intimate association of protozoa with a wide variety of other cells, either prokaryotic or eukaryotic in nature. Yet study of such relationships can provide important information concerning certain basic aspects of cellular evolution in general. A survey is offered here of the whole range of such symbiotic associations (i.e. with species of protozoa serving as hosts) with the purposes of drawing attention to the exciting possibilities of such research and of reviewing significant findings made to date. Because of the vastness of the overall field, examples and discussion are primarily limited to consideration of the following major studies: methanogenic bacteria in certain ciliates, bacterial endosymbionts of the large freshwater amoeba Pelomyxa palustris (itself an amazing organism from an evolutionary/phylogenetic point of view), the rod-shaped bacteria found in Amoeba proteus, the “Greek-letter” prokaryotes of Paramecium species, the xenosomes (sensu stricto) of the marine scuticociliate Parauronema acutum, and the diverse algal endosymbionts of similarly diverse protozoan taxa–ciliates, flagellates, radiolarians, acantharians, and foraminifera.
    Type of Medium: Electronic Resource
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 15
    Electronic Resource
    Electronic Resource
    Oxford, UK : Blackwell Publishing Ltd
    The @journal of eukaryotic microbiology 32 (1985), S. 0 
    ISSN: 1550-7408
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology
    Notes: .Attention, perhaps overdue, is drawn to the extent and significance of endosymbionts (xenosomes sensu lato) in the cytoplasm and nuclei of many protozoa from diverse taxonomic groups. Even more importantly, recent advances in the study of such intimate associations are reviewed and discussed and their impact on broader problems of cell biology and evolution are stressed. Workers inside and especially outside the fields of protozoology and parasitology have often neglected such data, failing to appreciate their relevance to significant problems in their own fields of investigation. The major topics covered by speakers in the Symposium (to which this paper serves only as an introduction) include the following, in order of their presentation: terminology for the symbiont-host relationship and a brief overview of the field; the evolutionary problem of the origin of contemporary associations, including cell organelles such as mitochondria and plastids; the adaptive value of endosymbionts to their protozoan hosts; mechanisms of establishment, maintenance, and integration of such foreign bodies/invaders in their unicellular eukaryotic host cells; and the extent of algal and bacterial endosymbioses in diverse protozoan groups. In all papers, the principal relatively well studied complexes used as examples are the following: various kinds of algae in the larger foraminifera and in ciliates, radiolarians, and acantharians; the several types of bacteria in the cytoplasm of Amoeba and of Pelomyxa; the endonuclear bacterial symbionts of Paramecium; the cytoplasmic prokaryotes in Paramecium and in Parauronema; and the methanogenic bacteria of certain ciliates.
    Type of Medium: Electronic Resource
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 16
    Electronic Resource
    Electronic Resource
    Oxford, UK : Blackwell Publishing Ltd
    The @journal of eukaryotic microbiology 13 (1966), S. 0 
    ISSN: 1550-7408
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology
    Notes: SYNOPSIS. Polysphondylium pallidum WS-320 grows indefinitely as vegetative amebae in a liquid medium where (a) substrates comprise sucrose, glycerol, acetate, lactate, citrate, and glutamate; (b) essential nutrients (riboflavin, lysine, glycine, and possibly several other amino acids that may be essential) are supplied. The growth thus supported (2 × 106 cells/ml) is more than doubled by provision of a mixture of crude fatty acids, an acid hydrolysate of casein supplemented with B vitamins, purines, pyrimidines, and fat-soluble antioxidants.
    Type of Medium: Electronic Resource
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 17
    ISSN: 1550-7408
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology
    Notes: . A species of Amphidinium bloomed in a mariculture sedimentation pond that was used to grow bivalves near the Gulf of Eilat, Israel. Its overall length averaged 13 μm, the hypocone was 11 μm, and its width was 8μm. It has a ventral ridge. The sulcus begins at the longitudinal flagellar pore and does not project forward in the apex toward the transverse flagellar pore and left margin of the cingulum. The sulcus is a very shallow groove that projects variably about a third of the body length toward the antapex. The cingulum is a deep groove as it circles the cell from the left ventral side to the dorsal side and then becomes very shallow on the right ventral side as it arches posterior toward the longitudinal flagellar pore. Using a modified method for studying dinoflagellate chromosomes in the SEM, we observed 31 chromosomes. The plastid is dorsal and peripheral with 6 ventrally projecting peripheral digital lobes that wrap around the sides of the ventral and posterior nucleus. Amphidinium eilatiensis n. sp. is morphologically closest to Amphidinium carterae and Amphidinium rhynchocephalum, but it does not have the obvious thecal plates or polygonal units described for the former species. Instead, it has a series of spicules, bumps, and ridges on its surface. It differs from A. rhynchocephalum by two morphological characters: surface morphology and gross plastid architecture.The amplified fragments of the rDNA from A. eilatiensis n. sp. isolated from 2 separate sedimentation ponds in Eilat include the 3′-end of the SSU rDNA (about 100 nt), the whole ITS region (ITS1 + 5. 8S + ITS2) and the 5′-end of the LSU rDNA (about 900 nts). The total length of the sequences ranged from 1,460 nt. (A. eilatiensis isolate #1) to 1,461 nts. (A. eilatiensis isolate #2). The latter sequences are identical, the difference in length being due to three insertions. Amphidinium eilatiensis is genetically more closely related to A. carterae than to A. klebsii, with respectively 2. 36% and 6. 93% of sequence divergence.
    Type of Medium: Electronic Resource
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 18
    Electronic Resource
    Electronic Resource
    Oxford, UK : Blackwell Publishing Ltd
    The @journal of eukaryotic microbiology 39 (1992), S. 0 
    ISSN: 1550-7408
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology
    Type of Medium: Electronic Resource
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 19
    Electronic Resource
    Electronic Resource
    Oxford, UK : Blackwell Publishing Ltd
    The @journal of eukaryotic microbiology 32 (1985), S. 0 
    ISSN: 1550-7408
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology
    Notes: .It is generally accepted that in symbiotic systems involving algal species as cellular endobionts there is some positive benefit to the host organisms. In this paper special consideration is given to the larger foraminifera, protozoa that serve as very useful model systems for the study of aspects of inter/intracellular integration and adaptation—living, as they do, in nutrient-limited but well illuminated shallow tropical seas and containing endosymbiotic algae in abundance. A considerable amount of information is now available on physiological as well as morphological adaptations of the host species to pigmented protists representing diverse algal divisions (phyla). Brief mention is also made of bacterial endosymbionts of certain ciliates.
    Type of Medium: Electronic Resource
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 20
    Electronic Resource
    Electronic Resource
    Oxford, UK : Blackwell Publishing Ltd
    The @journal of eukaryotic microbiology 27 (1980), S. 0 
    ISSN: 1550-7408
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology
    Notes: SYNOPSIS The time is ripe for protozoan ecologists to begin the general evaluation of the role of food quality in the energy transformations and materials flow in food webs involving protozoa and other small organisms. Current evidence suggests that major pathways of energy flow at any particular time depend upon the matches between prey species and consumers. There are 2 components to food quality related (informational) energy flow: (a) the information present in the molecular constitution of the prey; and (b) the ability of the protozoa to recognize and use it. If the evidence obtained from trophodynamic studies of 2 marine ciliates, Uronema marinum Dujardin and Euplotes vannus Müller indicates a generalized ability of protozoa to regulate catabolic reactions to points which optimize energetic gains from their food, then it may be one of the keys to the evolutionary successes of the group.
    Type of Medium: Electronic Resource
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...