Comparison of an inducible oxidative burst in free-living and symbiotic dinoflagellates reveals properties of the pseudopterosins

2004 ◽  
Vol 65 (24) ◽  
pp. 3231-3241 ◽  
Author(s):  
L MYDLARZ ◽  
R JACOBS
Keyword(s):  
Oxidative Burst ◽  
Free Living ◽  
Symbiotic Dinoflagellates

scholarly journals Structural rearrangements drive extensive genome divergence between symbiotic and free-living Symbiodinium

2019 ◽  
Author(s):  
Raúl A. González-Pech ◽  
Timothy G. Stephens ◽  
Yibi Chen ◽  
Amin R. Mohamed ◽  
Yuanyuan Cheng ◽  
...  
Keyword(s):  
Genome Size ◽  
Molecular Mechanisms ◽  
De Novo ◽  
Sequence Divergence ◽  
Gene Families ◽  
Homologous Gene ◽  
Structural Rearrangements ◽  
Free Living ◽  
Symbiotic Dinoflagellates ◽  
Genome Assemblies

AbstractSymbiodiniaceae are predominantly symbiotic dinoflagellates critical to corals and other reef organisms. Symbiodinium is a basal symbiodiniacean lineage and includes symbiotic and free-living taxa. However, the molecular mechanisms underpinning these distinct lifestyles remain little known. Here, we present high-quality de novo genome assemblies for the symbiotic Symbiodinium tridacnidorum CCMP2592 (genome size 1.3 Gbp) and the free-living Symbiodinium natans CCMP2548 (genome size 0.74 Gbp). These genomes display extensive sequence divergence, sharing only ~1.5% conserved regions (≥90% identity). We predicted 45,474 and 35,270 genes for S. tridacnidorum and S. natans, respectively; of the 58,541 homologous gene families, 28.5% are common to both genomes. We recovered a greater extent of gene duplication and higher abundance of repeats, transposable elements and pseudogenes in the genome of S. tridacnidorum than in that of S. natans. These findings demonstrate that genome structural rearrangements are pertinent to distinct lifestyles in Symbiodinium, and may contribute to the vast genetic diversity within the genus, and more broadly in Symbiodiniaceae. Moreover, the results from our whole-genome comparisons against a free-living outgroup support the notion that the symbiotic lifestyle is a derived trait in, and that the free-living lifestyle is ancestral to, Symbiodinium.

Studies on a nudibranch that contains zooxanthellae. II. Contribution of zooxanthellae to animal respiration (CZAR) in Pteraeolidia ianthina with high and low densities of zooxanthellae

1986 ◽  
Vol 228 (1253) ◽  
pp. 511-521 ◽  
Keyword(s):  
Mitotic Index ◽  
Specific Growth ◽  
Symbiotic Association ◽  
Diel Pattern ◽  
Fixed Carbon ◽  
Free Living ◽  
Carbon Demand ◽  
Symbiotic Dinoflagellates ◽  
Specific Growth Rates ◽  
Relationship Of

Daily budgets of photosynthetically fixed carbon were constructed for Pteraeolidia ianthina with high and low densities of zooxanthellae, for irradiances typical of latitude 34° S in winter, spring and summer. Whereas nudibranchs with high densities of zooxanthellae were potentially phototrophic with respect to carbon, animals with densities of zooxanthellae less than 0.5 x 10 6 cells mg -1 protein were not. The proportion of dividing zooxanthellae (mitotic index) in P. ianthina was followed over 48 hours. The diel pattern of mitotic index was asynchronous; the indices were higher in animals with low densities of zooxanthellae (20.1±6.2%) than in animals with high densities of zooxanthellae (4.7±1.8%). Specific growth rates of zooxanthellae, calculated from mitotic indices, ranged between 0.100 and 0.399 d -1 , indicating that zooxanthellae in P . ianthina have the potential to grow at rates comparable to those found in free-living and other symbiotic dinoflagellates. Zooxanthellae in the host photosynthesized at similar rates, irrespective of their density in P . ianthina . Because of the greater amount of newly synthesized carbon dedicated to the population growth of zooxanthellae, low-density populations did not have excess organic carbon available for host respiration. High density populations, however, were able to supply 79% of the animal’s respiratory carbon demand in winter, 121% in spring and 173% in summer. These results demonstrate that the metabolic relationship of zooxanthellae and their invertebrate hosts may change during the establishment of a symbiotic association.

Detecting reactive oxygen species in free-living symbiotic dinoflagellates exposed to nanoparticles v1

2021 ◽  
Author(s):  
Liza M M Roger ◽  
Nastassja Lewinski
Keyword(s):  
Oxidative Stress ◽  
Reactive Oxygen Species ◽  
Cell Membrane ◽  
Fluorescent Probe ◽  
Cellular Systems ◽  
Oxygen Species ◽  
Free Living ◽  
Fluorescent Compound ◽  
H2o2 Formation ◽  
Symbiotic Dinoflagellates

2',7'-dichlorodihydrofluorescein diacetate (DCFH-DA) is a popular fluorescent probe for the detection of oxidative stress in cells. Since the probe can be prone to auto-oxidation, carboxy-2',7'-dichlorodihydrofluorescein-diacetate (carboxy-H2DCF-DA) which is more stable and easily penetrates cell membranes is often reported in the literature instead. Upon crossing the cell membrane, esterases hydrolyse DCFH-DA to DCFH, which remains trapped within cells. The oxidation of DCFH yields DCF, a fluorescent compound which can be measured using excitation/emission wavelengths of 485-495/520-530 nm. Due to several cases of interference when used in cellular systems, DCFH-DA is a general marker of the cellular oxidative stress rather than a specific indicator H2O2 formation or other ROS.

Detecting nitric oxide in free-living symbiotic dinoflagellates exposed to nanoparticles v1

2021 ◽  
Author(s):  
Liza M Roger ◽  
Nastassja Lewinski
Keyword(s):  
Nitric Oxide ◽  
Cell Membrane ◽  
Free Living ◽  
Fluorescent Indicator ◽  
Symbiotic Dinoflagellates ◽  
Oxidation Of No

Diaminofuorescein-2 diacetate (DAF-2 DA) is a fluorescent indicator of nitric oxide (NO). The DAF reacts with the nitric anhydride (N2O3) which formed by oxidation of NO. Upon crossing the cell membrane, esterases hydrolyse DAF-2 DA to DAF-2, which remains trapped within cells. The DAF-2 reacts to the oxidation of intracellular NO (or more accurately the N2O3) to produce the highly fluorescent triazolofluorescein (DAF-2T) by nitrosation and dehydration (Kojima et al., 1999). Protocol adapted from Bouchard & Yamasaki (2009) and Kojima et al. (1999)

Ultrastructure of neuromuscular relationships in the canine heartworm (dirofilaria immitis)

1986 ◽  
Vol 44 ◽  
pp. 278-279
Author(s):  
W. L. Steffens ◽  
Nancy B. Roberts ◽  
J. M. Bowen
Keyword(s):  
Dirofilaria Immitis ◽  
Domestic Dogs ◽  
Structural Description ◽  
Pharmacological Effects ◽  
Free Living ◽  
Canine Heartworm ◽  
The World ◽  
Synaptic Region ◽  
Muscle Innervation ◽  
Insight Into

The canine heartworm is a common and serious nematode parasite of domestic dogs in many parts of the world. Although nematode neuroanatomy is fairly well documented, the emphasis has been on sensory anatomy and primarily in free-living soil species and ascarids. Lee and Miller reported on the muscular anatomy in the heartworm, but provided little insight into the peripheral nervous system or myoneural relationships. The classical fine-structural description of nematode muscle innervation is Rosenbluth's earlier work in Ascaris. Since the pharmacological effects of some nematacides currently being developed are neuromuscular in nature, a better understanding of heartworm myoneural anatomy, particularly in reference to the synaptic region is warranted.

Lead and lead toxicity in domestic and free living birds

2003 ◽  
Vol 32 (1) ◽  
pp. 3-13 ◽  
Author(s):  
N. De Francisco ◽  
N. De Francisco ◽  
N. De Francisco
Keyword(s):  
Lead Toxicity ◽  
Free Living

Platelet Aggregation in Finnish Men and Its Relation to Fatty Acids in Platelets, Plasma and Adipose Tissue

1985 ◽  
Vol 54 (03) ◽  
pp. 563-569 ◽  
Author(s):  
M K Salo ◽  
E Vartiainen ◽  
P Puska ◽  
T Nikkari
Keyword(s):  
Fatty Acids ◽  
Adipose Tissue ◽  
Fatty Acid Composition ◽  
Fatty Acid ◽  
Platelet Aggregation ◽  
Acid Composition ◽  
Saturated Fatty Acids ◽  
Free Living ◽  
Ω3 Fatty Acids ◽  
Induced Aggregation

SummaryPlatelet aggregation and its relation to fatty acid composition of platelets, plasma and adipose tissue was determined in 196 randomly selected, free-living, 40-49-year-old men in two regions of Finland (east and southwest) with a nearly twofold difference in the IHD rate.There were no significant east-southwest differences in platelet aggregation induced with ADP, thrombin or epinephrine. ADP-induced platelet secondary aggregation showed significant negative associations with all C20-C22 ω3-fatty acids in platelets (r = -0.26 - -0.40) and with the platelet 20: 5ω3/20: 4ω 6 and ω3/ ω6 ratios, but significant positive correlations with the contents of 18:2 in adipose tissue (r = 0.20) and plasma triglycerides (TG) (r = 0.29). Epinephrine-induced aggregation correlated negatively with 20: 5ω 3 in plasma cholesteryl esters (CE) (r = -0.23) and TG (r = -0.29), and positively with the total percentage of saturated fatty acids in platelets (r = 0.33), but had no significant correlations with any of the ω6-fatty acids. Thrombin-induced aggregation correlated negatively with the ω3/6ω ratio in adipose tissue (r = -0.25) and the 20: 3ω6/20: 4ω 6 ratio in plasma CE (r = -0.27) and free fatty acids (FFA) (r = -0.23), and positively with adipose tissue 18:2 (r = 0.23) and 20:4ω6 (r = 0.22) in plasma phospholipids (PL).The percentages of prostanoid precursors in platelet lipids, i. e. 20: 3ω 6, 20: 4ω 6 and 20 :5ω 3, correlated best with the same fatty acids in plasma CE (r = 0.32 - 0.77) and PL (r = 0.28 - 0.74). Platelet 20: 5ω 3 had highly significant negative correlations with the percentage of 18:2 in adipose tissue and all plasma lipid fractions (r = -0.35 - -0.44).These results suggest that, among a free-living population, relatively small changes in the fatty acid composition of plasma and platelets may be reflected in significant differences in platelet aggregation, and that an increase in linoleate-rich vegetable fat in the diet may not affect platelet function favourably unless it is accompanied by an adequate supply of ω3 fatty acids.

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