N‐ASSIMILATION IN THE NOXIOUS FLAGELLATE HETEROSIGMA CARTERAE (RAPHIDOPHYCEAE): DEPENDENCE ON LIGHT, N‐SOURCE, AND PHYSIOLOGICAL STATE 1

2002 ◽  
Vol 38 (3) ◽  
pp. 503-512 ◽  
Author(s):  
Darren R. Clark ◽  
Kevin J. Flynn
Keyword(s):  
Physiological State ◽  
N Source ◽  
N Assimilation ◽  
Heterosigma Carterae ◽  
State 1

scholarly journals Production and cross-feeding of nitrite within Prochlorococcus populations

2022 ◽  
Author(s):  
Paul M Berube ◽  
Tyler J O'Keefe ◽  
Anna N Rasmussen ◽  
Sallie W Chisholm
Keyword(s):  
Batch Culture ◽  
Exponential Growth ◽  
Photosynthetic Bacterium ◽  
High Light ◽  
Low Light ◽  
N Cycle ◽  
N Source ◽  
Production And Consumption ◽  
N Assimilation ◽  
Single Clade

Prochlorococcus is an abundant photosynthetic bacterium in the oligotrophic open ocean where nitrogen (N) often limits the growth of phytoplankton. Prochlorococcus has evolved into multiple phylogenetic clades of high-light (HL) adapted and low-light (LL) adapted cells. Within these clades, cells encode a variety of N assimilation traits that are differentially distributed among members of the population. Among these traits, nitrate (NO3-) assimilation is generally restricted to a few clades of high-light adapted cells (the HLI, HLII, and HLVI clades) and a single clade of low-light adapted cells (the LLI clade). Most, if not all, cells belonging to the LLI clade have the ability to assimilate nitrite (NO2-), with a subset of this clade capable of assimilating both NO3- and NO2-. Cells belonging to the LLI clade are maximally abundant at the top of the nitracline and near the primary NO2- maximum layer. In some ecosystems, this peak in NO2- concentration may be a consequence of incomplete assimilatory NO3- reduction by phytoplankton. This phenomenon is characterized by a bottleneck in the downstream half of the NO3- assimilation pathway and the concomitant accumulation and release of NO2- by phytoplankton cells. Given the association between LLI Prochlorococcus and the primary NO2- maximum layer, we hypothesized that some Prochlorococcus exhibit incomplete assimilatory NO3- reduction. To assess this, we monitored NO2- accumulation in batch culture for 3 Prochlorococcus strains (MIT0915, MIT0917, and SB) and 2 Synechococcus strains (WH8102 and WH7803) when grown on NO3- as the sole N source. Only MIT0917 and SB accumulated external NO2- during growth on NO3-. Approximately 20-30% of the NO3- transported into the cell by MIT0917 was released as NO2-, with the balance assimilated into biomass. We further observed that co-cultures using NO3- as the sole N source could be established for MIT0917 and a Prochlorococcus strain that can assimilate NO2- but not NO3-. In these co-cultures, the NO2- released by MIT0917 was efficiently consumed by its partner strain during balanced exponential growth. Our findings highlight the potential for emergent metabolic partnerships within Prochlorococcus populations that are mediated by the production and consumption of the N cycle intermediate, NO2-.

scholarly journals Plant nitrogen uptake and assimilation: regulation of cellular pH homeostasis

2020 ◽  
Vol 71 (15) ◽  
pp. 4380-4392 ◽  
Author(s):  
Huimin Feng ◽  
Xiaorong Fan ◽  
Anthony J Miller ◽  
Guohua Xu
Keyword(s):  
Intracellular Ph ◽  
Ph Regulation ◽  
N Uptake ◽  
Plant Cells ◽  
Proton Pumps ◽  
Ph Homeostasis ◽  
Long Distance ◽  
N Source ◽  
N Assimilation ◽  
In Cells

Abstract The enzymatic controlled metabolic processes in cells occur at their optimized pH ranges, therefore cellular pH homeostasis is fundamental for life. In plants, the nitrogen (N) source for uptake and assimilation, mainly in the forms of nitrate (NO3–) and ammonium (NH4+) quantitatively dominates the anion and cation equilibrium and the pH balance in cells. Here we review ionic and pH homeostasis in plant cells and regulation by N source from the rhizosphere to extra- and intracellular pH regulation for short- and long-distance N distribution and during N assimilation. In the process of N transport across membranes for uptake and compartmentation, both proton pumps and proton-coupled N transporters are essential, and their proton-binding sites may sense changes of apoplastic or intracellular pH. In addition, during N assimilation, carbon skeletons are required to synthesize amino acids, thus the combination of NO3– or NH4+ transport and assimilation results in different net charge and numbers of protons in plant cells. Efficient maintenance of N-controlled cellular pH homeostasis may improve N uptake and use efficiency, as well as enhance the resistance to abiotic stresses.

scholarly journals Effect of N Source on the Steady State Growth and N Assimilation of P-limited Anabaena flos-aquae

1985 ◽  
Vol 78 (4) ◽  
pp. 739-745 ◽  
Author(s):  
David B. Layzell ◽  
David H. Turpin ◽  
Ivor R. Elrifi
Keyword(s):  
Steady State ◽  
Steady State Growth ◽  
N Source ◽  
N Assimilation ◽  
State Growth

Advances in Microprobe Analysis Applied to Muscle, Nerve and Gland

1982 ◽  
Vol 40 ◽  
pp. 404-407
Author(s):  
T. E. Hutchinson ◽  
D. E. Johnson ◽  
A. C. Lee ◽  
E. Y. Wang
Keyword(s):  
Biological Tissue ◽  
Microprobe Analysis ◽  
Physiological State ◽  
External Environment ◽  
Physiological Relevance ◽  
Muscle Nerve ◽  
Technique Development

Microprobe analysis of biological tissue is now in the end phase of transition from instrumental and technique development to applications pertinent to questions of physiological relevance. The promise,implicit in early investigative efforts, is being fulfilled to an extent much greater than many had predicted. It would thus seem appropriate to briefly report studies exemplifying this, ∿. In general, the distributions of ions in tissue in a preselected physiological state produced by variations in the external environment is of importance in elucidating the mechanisms of exchange and regulation of these ions.

Conformational characterization of nucleosome structure by Electron Microscopy

1993 ◽  
Vol 51 ◽  
pp. 194-195
Author(s):  
Gregory J. Czarnota
Keyword(s):  
Electron Microscopy ◽  
Structural Changes ◽  
Physiological State ◽  
Gene Activation ◽  
Three Dimensional ◽  
Macromolecular Complex ◽  
Ultrastructural Studies ◽  
Ionic Environment ◽  
Nucleosome Structure ◽  
Dimensional Reconstruction

Chromatin structure at the fundamental level of the nucleosome is important in vital cellular processes. Recent biochemical and genetic analyses show that nucleosome structure and structural changes are very active participants in gene expression, facilitating or inhibiting transcription and reflecting the physiological state of the cell. Structural states and transitions for this macromolecular complex, composed of DNA wound about a heterotypic octamer of variously modified histone proteins, have been measured by physico-chemical techniques and by enzyme-accessibility and are recognized to occur with various post-translational modifications, gene activation, transformation and with ionic-environment. In spite of studies which indicate various forms of nucleosome structure, all current x-ray and neutron diffraction studies have consistently resulted in only one structure, suggestive of a static conformation. In contrast, two-dimensional electron microscopy studies and three-dimensional reconstruction techniques have yielded different structures. These fundamental differences between EM and other ultrastructural studies have created a long standing quandary, which I have addressed and resolved using spectroscopic electron microscopy and statistical analyses of nucleosome images in a study of nucleosome structure with ionic environment.

Stimulus + Physiological State = Behavior

1980 ◽  
Vol 25 (3) ◽  
pp. 265-266
Author(s):  
JACQUELINE LUDEL
Keyword(s):  
Physiological State ◽  
State Behavior

Neonatal nutritional strategy of a viviparous elasmobranch with extremely low reproductive output

2020 ◽  
Vol 638 ◽  
pp. 107-121 ◽  
Author(s):  
BS Rangel ◽  
NE Hussey ◽  
Y Niella ◽  
LA Martinelli ◽  
AD Gomes ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Reproductive Strategies ◽  
Trophic Ecology ◽  
Essential Fatty Acids ◽  
Physiological State ◽  
Maternal Investment ◽  
Early Life History ◽  
Nutritional State ◽  
Disc Width ◽  
Biomarker Analysis

Throughout evolutionary history, elasmobranchs have developed diverse reproductive strategies. Little focused work, however, has addressed how neonatal nutritional state is affected by differing degrees of maternal investment associated with these markedly different reproductive strategies. To investigate the effect of maternal investment on the nutritional quality of pups during the early life history of an extremely viviparous elasmobranch, quantitative biomarker analysis including lipids, fatty acids and stable isotopes was conducted. Using the cownose ray Rhinoptera bonasus (histotrophic viviparous) as a model, we found that pups were initially born in a positive nutritional state, enriched in physiologically important essential fatty acids and nitrogen and carbon stable isotope values (δ15N and δ13C), a result of maternal intrauterine transfer. A systematic decrease in some fatty acids and δ15N values, as well as a decrease in cholesterol with growth, confirmed that these substrates were derived from maternal resources and used in initial metabolic processes following birth. An observed increase in condition factor, plasma essential fatty acids and triglyceride:cholesterol ratio with increasing body size identified a progression towards successful independent foraging with pups not displaying marked nutritional deficiency or fasting phases. Our multi-tracer approach allowed the identification of 2 size classes of young rays (<50 and <70 cm disc width) that displayed distinct physiological states. Since prenatal maternal investment is critical for offspring condition and to promote successful foraging post birth, understanding the trophic ecology and physiological state of pups during their first year is critical to guide management and conservation within nursery grounds.

INFLUENCE OF HIGH-PROTEIN FEED ADDITIVE ON THE PRODUCTIVITY OF THE MEAT BULL-CALVES

2019 ◽  
Vol 2019 (3) ◽  
pp. 6-11
Author(s):  
Батырхан Абилов ◽  
Batyrkhan Abilov ◽  
Лариса Пашкова ◽  
Larisa Pashkova
Keyword(s):  
Hematological Parameters ◽  
Physiological State ◽  
Average Daily Gain ◽  
Live Weight ◽  
Feed Additive ◽  
North Caucasus ◽  
Agricultural Enterprise ◽  
Bull Calves ◽  
Economic Indices ◽  
High Level

The article presents the data obtained as a result of carrying by employees of the Research Institute of sheep and goat breeding, a branch of the FSBSI "North Caucasus FARC", the scientific and economic experience to study the efficiency of a new fodder additive "Organic" on the productive and physiological indices of bull-calves during the completion of growing in the conditions of the farm "Pata" agricultural enterprise in the Karachay-Cherkessia Republic. The statement of the experience and all researches were carried out according to generally accepted methods. In the course of the experiment, the following indices were studied: the chemical compound of forages, the dynamics of a live weight gain in the experimental stock, hematological parameters, control slaughter data, economic indices. Completed researches have shown positive result from the use of the fodder additive "Organic" in bull-calves diets: an increase in the average daily gain of live weight by 25%, a slaughter yield by 1% and a high level of profitability – 27%. Thus, the additional introduction of "Organic" in a diet of young horned cattle in the 2nd experimental group promoted more intensive metabolism, stabilization of a physiological state, increase in productivity and, as a consequence, profitability of beef production. Researches in this direction reveal the latent fodder reserves promoting increase in the productivity of agricultural animals.

STEROID HORMONE METABOLISM IN RESPONSIVE TISSUES IN VITRO

1971 ◽  
Vol 68 (1_Suppl) ◽  
pp. S279-S294 ◽  
Author(s):  
Paul Robel
Keyword(s):  
Steroid Hormone ◽  
Physiological Activity ◽  
Physiological State ◽  
Target Cells ◽  
Target Tissue ◽  
Hormone Metabolism ◽  
Metabolizing Enzymes ◽  
Relationship Of

ABSTRACT Of the information available on steroid hormone metabolism in responsive tissues, only that relating hormone metabolism to physiological activity is reviewed, i. e. metabolite activity in isolated in vitro systems, binding of metabolites to target tissue receptors, specific steroid hormone metabolizing enzymes and relationship of hormone metabolism to target organ physiological state. Further, evidence is presented in the androgen field, demonstrating 5α-reduced metabolites, formed inside the target cells, as active compounds. This has led to a consideration of testosterone as a »prehormone«. The possibility that similar events take place in tissues responding to progesterone is discussed. Finally, the role of hormone metabolism in the regulation of hormone availability and/or renewal in target cells is discussed. In this context, reference is made to the potential role of plasma binding proteins and cytosol receptors.

THE UPTAKE OF (6,7-3H) 17β-OESTRADIOL BY TISSUES OF THE DOMESTIC FOWL

1969 ◽  
Vol 60 (2) ◽  
pp. 199-209 ◽  
Author(s):  
R. A. Hawkins ◽  
P. J. Heald ◽  
Patricia Taylor
Keyword(s):  
Pituitary Gland ◽  
Intravenous Injection ◽  
Domestic Fowl ◽  
Physiological State ◽  
Laying Hen ◽  
Adult Bird

ABSTRACT A limited investigation of the distribution of radioactivity in the tissues of the adult laying hen has been made at differing times after intravenous injection of (6,7-3H) 17β-oestradiol. Uptake by all tissues examined was maximal between 2.0 and 4.0 minutes after injection. There was a marked retention of radioactivity by the oviduct and the liver. Of cerebral tissues examined the uptake of radioactivity was greatest in the pituitary gland. This uptake varied according to the physiological state of the bird. Calculations based on the rates of clearance of intravenous (6,7-3H) 17β-oestradiol indicate that in the adult bird the rate of secretion by the ovary is of the order of 1–2.0 mg oestradiol/24 h.

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