scholarly journals Coral symbiotic algae calcifyex hospitein partnership with bacteria

2015 ◽  
Vol 112 (19) ◽  
pp. 6158-6163 ◽  
Author(s):  
Jörg C. Frommlet ◽  
Maria L. Sousa ◽  
Artur Alves ◽  
Sandra I. Vieira ◽  
David J. Suggett ◽  
...  
Keyword(s):  
Life History ◽  
Coral Reef ◽  
Evolutionary History ◽  
Central Importance ◽  
Free Living ◽  
Algal Communities ◽  
Symbiotic Algae ◽  
Coral Reef Ecosystems ◽  
History Of

Dinoflagellates of the genusSymbiodiniumare commonly recognized as invertebrate endosymbionts that are of central importance for the functioning of coral reef ecosystems. However, the endosymbiotic phase withinSymbiodiniumlife history is inherently tied to a more cryptic free-living (ex hospite) phase that remains largely unexplored. Here we show that free-livingSymbiodiniumspp. in culture commonly form calcifying bacterial–algal communities that produce aragonitic spherulites and encase the dinoflagellates as endolithic cells. This process is driven bySymbiodiniumphotosynthesis but occurs only in partnership with bacteria. Our findings not only place dinoflagellates on the map of microbial–algal organomineralization processes but also point toward an endolithic phase in theSymbiodiniumlife history, a phenomenon that may provide new perspectives on the biology and ecology ofSymbiodiniumspp. and the evolutionary history of the coral–dinoflagellate symbiosis.

Introgression and selection shaped the evolutionary history of sympatric sister-species of coral reef fishes (genus:Haemulon)

2016 ◽  
Vol 26 (2) ◽  
pp. 639-652 ◽  
Author(s):  
Moisés A. Bernal ◽  
Michelle R. Gaither ◽  
W. Brian Simison ◽  
Luiz A. Rocha
Keyword(s):  
Coral Reef ◽  
Evolutionary History ◽  
Reef Fishes ◽  
Coral Reef Fishes ◽  
Sister Species ◽  
History Of

scholarly journals Myxosporea (Myxozoa, Cnidaria) Lack DNA Cytosine Methylation

2020 ◽  
Author(s):  
Ryan Kyger ◽  
Agusto Luzuriaga-Neira ◽  
Thomas Layman ◽  
Tatiana Orli Milkewitz Sandberg ◽  
Devika Singh ◽  
...  
Keyword(s):  
Evolutionary History ◽  
Cytosine Methylation ◽  
Bisulfite Sequencing ◽  
Regulatory Mechanism ◽  
Regulation Of Gene Expression ◽  
Biological Processes ◽  
Free Living ◽  
Genome Bisulfite Sequencing ◽  
History Of ◽  
Dna Cytosine Methylation

Abstract DNA cytosine methylation is central to many biological processes, including regulation of gene expression, cellular differentiation, and development. This DNA modification is conserved across animals, having been found in representatives of sponges, ctenophores, cnidarians, and bilaterians, and with very few known instances of secondary loss in animals. Myxozoans are a group of microscopic, obligate endoparasitic cnidarians that have lost many genes over the course of their evolution from free-living ancestors. Here, we investigated the evolution of the key enzymes involved in DNA cytosine methylation in 29 cnidarians and found that these enzymes were lost in an ancestor of Myxosporea (the most speciose class of Myxozoa). Additionally, using whole-genome bisulfite sequencing, we confirmed that the genomes of two distant species of myxosporeans, Ceratonova shasta and Henneguya salminicola, completely lack DNA cytosine methylation. Our results add a notable and novel taxonomic group, the Myxosporea, to the very short list of animal taxa lacking DNA cytosine methylation, further illuminating the complex evolutionary history of this epigenetic regulatory mechanism.

The influence of temperature on the life history of the Antarctic nematode Panagrolaimus davidi

Nematology ◽  
2004 ◽  
Vol 6 (6) ◽  
pp. 883-890 ◽  
Author(s):  
Russell Millar ◽  
David Wharton ◽  
Ian Brown
Keyword(s):  
Life History ◽  
Life History Strategy ◽  
Major Influence ◽  
Free Living ◽  
Egg Incubation ◽  
Polar Species ◽  
Threshold Temperatures ◽  
Influence Of Temperature On ◽  
History Of ◽  
The Antarctic

AbstractPanagrolaimus davidi is a free-living microbivore, associated with moss and algal patches in coastal regions around Ross Island, Antarctica. In laboratory experiments, temperature had a major influence on P. davidi life history parameters. The optimal temperature occurred between 25 and 30°C and the temperature at which population growth ceased was estimated at 6.8°C. Threshold temperatures for developmental processes were in the range 4.1°C (for egg incubation) to 7.6°C (for generation time). The life history strategy of P. davidi shows r-selected features and is more similar to temperate free-living nematodes than to other polar species, which show K-selected features. In the Antarctic, P. davidi is forced to remain dormant for long periods and growth occurs intermittently when conditions allow, suggesting A selection. The life history of P. davidi thus exhibits both A and r-selected features.

STUDIES ON STRONGYLOIDES OF PRIMATES: V. SYNONYMY OF THE SPECIES IN MONKEYS AND APES

1959 ◽  
Vol 37 (1) ◽  
pp. 75-81 ◽  
Author(s):  
Premvati
Keyword(s):  
Life History ◽  
Environmental Conditions ◽  
New World ◽  
Comparative Morphology ◽  
New World Primates ◽  
Free Living ◽  
Old World ◽  
History Of

A study of the comparative morphology and life history of S. fülleborni, S. cebus, and S. simiae in both the parasitic and free-living generations under different environmental conditions, and their comparison with the free-living stages from faeces of Old World and New World primates has led to the conclusion that the three species should be synonymized into one, for which the name Strongyloides fülleborni von Linstow (1905) has priority.

scholarly journals Genomic analysis finds no evidence of canonical eukaryotic DNA processing complexes in a free-living protist

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Dayana E. Salas-Leiva ◽  
Eelco C. Tromer ◽  
Bruce A. Curtis ◽  
Jon Jerlström-Hultqvist ◽  
Martin Kolisko ◽  
...  
Keyword(s):  
Evolutionary History ◽  
Origin Recognition Complex ◽  
Common Ancestor ◽  
Genomic Analysis ◽  
Free Living ◽  
A Genome ◽  
History Of ◽  
Eukaryotic Dna ◽  
Comparative Genomics Analysis ◽  
Dna Processing

AbstractCells replicate and segregate their DNA with precision. Previous studies showed that these regulated cell-cycle processes were present in the last eukaryotic common ancestor and that their core molecular parts are conserved across eukaryotes. However, some metamonad parasites have secondarily lost components of the DNA processing and segregation apparatuses. To clarify the evolutionary history of these systems in these unusual eukaryotes, we generated a genome assembly for the free-living metamonad Carpediemonas membranifera and carried out a comparative genomics analysis. Here, we show that parasitic and free-living metamonads harbor an incomplete set of proteins for processing and segregating DNA. Unexpectedly, Carpediemonas species are further streamlined, lacking the origin recognition complex, Cdc6 and most structural kinetochore subunits. Carpediemonas species are thus the first known eukaryotes that appear to lack this suite of conserved complexes, suggesting that they likely rely on yet-to-be-discovered or alternative mechanisms to carry out these fundamental processes.

scholarly journals Distribution and Evolutionary History of Sialic Acid Catabolism in the Phylum Actinobacteria

2022 ◽  
Author(s):  
Yisong Li ◽  
Ying Huang
Keyword(s):  
Sialic Acid ◽  
Evolutionary History ◽  
Sialic Acids ◽  
Free Living ◽  
Evolutionary Pathway ◽  
History Of

Sialic acids play essential roles in the physiology of humans and other metazoan animals, and microbial sialic acid catabolism (SAC) is one of the processes critical for pathogenesis. To date, microbial SAC is studied mainly in commensals and pathogens, while its distribution in free-living microbes and evolutionary pathway remain largely unexplored.

On the Morphology and Life History of Aproctonema entomophagum Keilin, a Nematode Parasite in the Larvae of Sciara pullula Winn. (Diptera—Nematocera)

Parasitology ◽  
1933 ◽  
Vol 25 (3) ◽  
pp. 285-295 ◽  
Author(s):  
D. Keilin ◽  
V. C. Robinson
Keyword(s):  
Life History ◽  
Systematic Position ◽  
Egg Laying ◽  
Nematode Parasite ◽  
Free Living ◽  
The Family ◽  
Two Generations ◽  
History Of ◽  
Decaying Wood

1. An account is given of Aproctonema entomophagum Keilin 1917, a Nematode parasite of the larvae of a Mycetophilid fly, Sciara pullula Winn., inhabiting decaying wood.2. The life history of this parasite is remarkable in the following respects:(a) The free-living stage is very short.(b) Both sexes are parasitic.(c) The usual host is the larva of the fly, from which the parasite escapes by actively breaking through the skin; but some parasites may be carried through to the imagines, from which they escape largely by the aid of the egg-laying movements provoked by them in the flies.3. Metamorphosis of the Sciara larva is delayed by the parasitism, so that at least two generations of Nematodes may be found in one host.4. All the parasitised imagines so far examined have been females.5. The systematic position of Aproctonema is discussed, the conclusion being that this worm and its near relative, Tetradonema plicans Cobb 1919, represent two closely allied genera of the family Mermithidae, but are not synonymous with Mermis. It is proposed to dispense with the family Tetra-donematidae Cobb.

The function and evolution of penicillinase

1971 ◽  
Vol 179 (1057) ◽  
pp. 385-401 ◽  
Keyword(s):  
Life History ◽  
Chemical Structure ◽  
Evolutionary History ◽  
Physiological Function ◽  
Biochemical Evolution ◽  
Structural Genes ◽  
Ecological Relationships ◽  
History Of ◽  
Intimate Knowledge ◽  
Specific Inhibitors

In order to construct biologically useful hypotheses on plausible pathways for the evolution of an enzyme, it is important to know something about the probable physiological function, as well as the chemistry, of the molecular varieties existing at present. Yet, function of a part of an organism—be it a morphological entity or simply a species of protein—is a notoriously subjective quality, difficult to assess without intimate knowledge of the life history of the organism and its natural ecological relationships. Chemical structure, for these purposes, is equivalent to amino acid sequence, for it is by comparison of different sequences in a homologous series of proteins that some idea can be obtained as to the most likely steps in their biochemical evolution at the level of the structural genes concerned. In this critical review, it is argued that existing evidence on the whole tends to favour the conclusion that the β-lactamases function in general as detoxifying agents, acting against the penicillins and cephalosporins, and that their evolutionary history has been tuned by selection in a natural environment where these classes of compound have operated as specific inhibitors of bacterial growth.

STUDIES ON STRONGYLOIDES OF PRIMATES: I. MORPHOLOGY AND LIFE HISTORY OF STRONGYLOIDES FÜLLEBORNI VON LINSTOW, 1905

1958 ◽  
Vol 36 (1) ◽  
pp. 65-77 ◽  
Author(s):  
Premvati
Keyword(s):  
Life History ◽  
Rhesus Monkeys ◽  
Free Living ◽  
History Of

A detailed description is given of the parasitic females and free-living stages of Slrongyloides fiilleborni von Linstow, 1905, from Indian rhesus monkeys.

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