scholarly journals Osmoregulation in Drosophila melanogaster selected for urea tolerance

1999 ◽  
Vol 202 (17) ◽  
pp. 2349-2358 ◽  
Author(s):  
V.A. Pierce ◽  
L.D. Mueller ◽  
A.G. Gibbs
Keyword(s):  
Amino Acids ◽  
Drosophila Melanogaster ◽  
Toxic Effects ◽  
Physiological Adaptation ◽  
Organic Osmolytes ◽  
Per Se ◽  
Body Compartments ◽  
And Control

Animals may adapt to hyperosmolar environments by either osmoregulating or osmoconforming. Osmoconforming animals generally accumulate organic osmolytes including sugars, amino acids or, in a few cases, urea. In the latter case, they also accumulate ‘urea-counteracting’ solutes to mitigate the toxic effects of urea. We examined the osmoregulatory adaptation of Drosophila melanogaster larvae selected to live in 300 mmol l(−)(1) urea. Larvae are strong osmoregulators in environments with high NaCl or sucrose levels, but have increased hemolymph osmolarity on urea food. The increase in osmolarity on urea food is smaller in the selected larvae relative to unselected control larvae, and their respective hemolymph urea concentrations can account for the observed increases in total osmolarity. No other hemolymph components appear to act as urea-counteractants. Urea is calculated to be in equilibrium across body compartments in both selected and control larvae, indicating that the selected larvae are not sequestering it to lower their hemolymph osmolarity. The major physiological adaptation to urea does not appear to involve increased tolerance or improved osmoregulation per se, but rather mechanisms (e.g. metabolism, decreased uptake or increased excretion) that reduce overall urea levels and the consequent toxicity.

scholarly journals Genetic and Molecular Characterization of sting, a Gene Involved in Crystal Formation and Meiotic Drive in the Male Germ Line of Drosophila melanogaster

Genetics ◽  
1999 ◽  
Vol 151 (2) ◽  
pp. 749-760 ◽  
Author(s):  
Armin Schmidt ◽  
Gioacchino Palumbo ◽  
Maria P Bozzetti ◽  
Patrizia Tritto ◽  
Sergio Pimpinelli ◽  
...  
Keyword(s):  
Amino Acids ◽  
Drosophila Melanogaster ◽  
Null Allele ◽  
Germ Line ◽  
Meiotic Drive ◽  
P Element ◽  
Crystal Formation ◽  
Male Sterile ◽  
Male Sterile Mutation

Abstract The sting mutation, caused by a P element inserted into polytene region 32D, was isolated by a screen for male sterile insertions in Drosophila melanogaster. This sterility is correlated with the presence of crystals in spermatocytes and spermatids that are structurally indistinguishable from those produced in males carrying a deficiency of the Y-linked crystal (cry) locus. In addition, their morphology is needle-like in Ste+ flies and star-shaped in Ste flies, once again as observed in cry– males. The sti mutation leads to meiotic drive of the sex chromosomes, and the strength of the phenomenon is correlated with the copy number of the repetitive Ste locus. The same correlation is also true for the penetrance of the male sterile mutation. A presumptive sti null allele results in male sterility and lethal maternal effect. The gene was cloned and shown to code for a putative protein that is 866 amino acids long. A C-terminal domain of 82 amino acids is identified that is well conserved in proteins from different organisms. The gene is expressed only in the germline of both sexes. The interaction of sting with the Ste locus can also be demonstrated at the molecular level. While an unprocessed 8-kb Ste primary transcript is expressed in wild-type males, in X/Y homozygous sti males, as in X/Y cry– males, a 0.7-kb mRNA is produced.

Toxic Effects of Amino-Acids and Amines on Seedling Growth

Nature ◽  
1947 ◽  
Vol 160 (4059) ◽  
pp. 222-223 ◽  
Author(s):  
L. J. AUDUS ◽  
J. H. QUASTEL
Keyword(s):  
Amino Acids ◽  
Seedling Growth ◽  
Toxic Effects

scholarly journals Social modulation of oogenesis and egg-laying in Drosophila melanogaster

2021 ◽  
Author(s):  
Bailly Tiphaine ◽  
Philip Kohlmeier ◽  
Rampal Etienne ◽  
Bregje Wertheim ◽  
Jean-Christophe Billeter
Keyword(s):  
Drosophila Melanogaster ◽  
Social Context ◽  
Social Systems ◽  
Fruit Fly ◽  
Egg Laying ◽  
Physiological Adaptation ◽  
Group Members ◽  
Selection For ◽  
Underlying Mechanisms ◽  
Gravid Females

Being part of a group facilitates cooperation between group members, but also creates competition for limited resources. This conundrum is problematic for gravid females who benefit from being in a group, but whose future offspring may struggle for access to nutrition in larger groups. Females should thus modulate their reproductive output depending on their social context. Although social-context dependent modulation of reproduction is documented in a broad range of species, its underlying mechanisms and functions are poorly understood. In the fruit fly Drosophila melanogaster, females actively attract conspecifics to lay eggs on the same resources, generating groups in which individuals may cooperate or compete. The tractability of the genetics of this species allows dissecting the mechanisms underlying physiological adaptation to their social context. Here, we show that females produce eggs increasingly faster as group size increases. By laying eggs faster in group than alone, females appear to reduce competition between offspring and increase their likelihood of survival. In addition, females in a group lay their eggs during the light phase of the day, while isolated females lay them during the night. We show that responses to the presence of others are determined by vision through the motion detection pathway and that flies from any sex, mating status or species can trigger these responses. The mechanisms of this modulation of egg-laying by group is connected to a lifting of the inhibition of light on oogenesis and egg-laying by stimulating hormonal pathways involving juvenile hormone. Because modulation of reproduction by social context is a hallmark of animals with higher levels of sociality, our findings represent a protosocial mechanism in a species considered solitary that may have been the target of selection for the evolution of more complex social systems.

scholarly journals Scientific Background of Dairy Protein Digestibility: A Review

2014 ◽  
Vol 7 ◽  
pp. 1-8 ◽  
Author(s):  
Ashok Kumar Shrestha
Keyword(s):  
Amino Acids ◽  
Whey Proteins ◽  
Protein Digestibility ◽  
In Vitro Digestion ◽  
Dairy Proteins ◽  
Dairy Foods ◽  
Dairy Protein ◽  
Protein Rich ◽  
And Control

Recent advances have shown that differences in compositional, structural and physical properties of caseins and whey proteins affect their digestion and absorption behavior, hormonal response, satiety effect and other physiological effects. For example, the ingestion of whey protein cause fast, high and transient increase of amino acids ‘fast protein’, whereas casein induce slower, lower and prolonged increase of ‘slow protein’ in the gut. Knowledge of, and control over, the rate and nature of digestive breakdown of dairy proteins provides a potential basis for product/process innovation through identifying ingredients and formulations that provide desired nutrient delivery profiles. With this background, the aim of our current review paper is to understand the digestion behavior of various protein-rich milk powders and their potential use in formulation of dairy foods for controlled release of amino acids and energy. Currently available in vitro protein digestibility methods to measure or predict the dairy protein digestibility were also investigated. The author has also presented the preliminary results of ongoing study on in vitro digestion of various commercial proteins powders.DOI: http://dx.doi.org/10.3126/jfstn.v7i0.10560 J. Food Sci. Technol. Nepal, Vol. 7 (1-8), 2012

scholarly journals Creativity and Control: A Paradox—Evidence from the Levers of Control Framework

2017 ◽  
Vol 29 (2) ◽  
pp. 73-96 ◽  
Author(s):  
Roland F. Speklé ◽  
Hilco J. van Elten ◽  
Sally K. Widener
Keyword(s):  
Survey Data ◽  
Structural Equation Model ◽  
Structural Equation ◽  
Equation Model ◽  
Organizational Success ◽  
Business Unit ◽  
Control Framework ◽  
Per Se ◽  
And Control ◽  
Levers Of Control

ABSTRACT Both control and creativity are important drivers of organizational success (Gilson, Mathieu, Shalley, and Ruddy 2005; Hirst, van Knippenberg, Chen, and Sacramento 2011). However, they are often regarded as conflicting. We use the Levers of Control (LoC) framework to examine the relationships between a system of controls, empowerment, and creativity. Using survey data from 233 business unit managers, a structural equation model shows that the intensity of use of a LoC system of controls is positively associated with both empowerment and creativity. This suggests that the LoC system provides an environment that is rich with information and motivates employees to take action in purposeful, directed ways. This environment facilitates employees' perception that they have the ability to take actions, make decisions, and produce novel ideas. We conclude that there is not a conflict between control and creativity per se. Rather, paradoxically, creativity can flourish in the presence of control.

scholarly journals Thermal stability of amino acids in meals and feeds used in shrimp farming

Gaia Scientia ◽  
2016 ◽  
Vol 10 (4) ◽  
pp. 372-389
Author(s):  
João Paulo de Sousa Prado ◽  
José Marcelino Oliveira Cavalheiro ◽  
Thiago Brandão Cavalheiro ◽  
Fernanda Vanessa Gomes da Silva
Keyword(s):  
Amino Acids ◽  
Elevated Temperatures ◽  
Amino Acid Content ◽  
Storage Conditions ◽  
Shrimp Farming ◽  
Protein Levels ◽  
Commercial Feed ◽  
The Stability ◽  
The Right ◽  
And Control

The Brazilian shrimp farming uses mainly commercial feed for shrimp nutrition. This choice occurs because of the advantages related to convenience and good adaptation of Litopenaeus vannanmei to feed intake. Thus, the quality of feed is a determining factor for maximum performance of the shrimp farms, making the right selection of suppliers and control of the storage conditions as ways to prevent contamination and spoilage of feed. The objective of this study was to evaluate the stability of amino acids in meals and commercial feed with different protein levels, subjected to high-temperature storage. The samples were exposed to temperature of 50 oC and evaluated every 5 days for 30 days.The analyses of the degradation of amino acids were performed using an elution gradient in HPLC system.In evaluated meals it was observed that valine and arginine were the amino acids that suffered greater loss during the experiment and histidine and alanine suffered less degradation.Significant difference was observed in the content of all amino acids analyzed after exposure of the feed to the temperature of 50 oC; with reduce in values of its amino acid content. The results obtained in this study indicate that meals and feed exposed to elevated temperatures significantly reduced the content of its amino acids.

scholarly journals Genetic encoding of non-natural amino acids in Drosophila melanogaster Schneider 2 cells

2010 ◽  
Vol 19 (3) ◽  
pp. 440-448 ◽  
Author(s):  
Takahito Mukai ◽  
Motoaki Wakiyama ◽  
Kensaku Sakamoto ◽  
Shigeyuki Yokoyama
Keyword(s):  
Amino Acids ◽  
Drosophila Melanogaster ◽  
Genetic Encoding ◽  
Natural Amino Acids

Investigation of Optimum Conformations and Structure Analysis of RL and LR Nests using Ramachandran Plot

2015 ◽  
pp. 209-224
Author(s):  
Sumukh Deshpande ◽  
Saikat Kumar Basu ◽  
Pooja Purohit
Keyword(s):  
Amino Acids ◽  
Ring Structure ◽  
Ramachandran Plot ◽  
Binding Motifs ◽  
Automated Algorithm ◽  
Automation And Control ◽  
The Common ◽  
And Control ◽  
Common Anion ◽  
Unique Application

We have surveyed polypeptides with the optimal conformations of nests which are the common anion-binding motifs comprising 8% of the amino acids which are characterized by a structural depression or a hole. Using automated bioinformatics algorithm, novel ring structure of the nest has been found. Using automated algorithm, models of polypeptides were made in-silico (computationally) and oxygen atoms are inserted along the extension of the NH groups. These sophisticated algorithms allow insertion of atoms along the NH group at the correct distance which causes extension of the group thus forming hydrogen bond. Optimal conformations of these structures are found from these customized models. This study chapter provides a demonstration of an important discovery of optimum conformations of RL and LR nests by the use of sophisticated bioinformatics automation pipeline and a unique application of automation and control in bioinformatics.

Contribution of bile to postprandial intestinal hyperemia

1980 ◽  
Vol 238 (4) ◽  
pp. G284-G288 ◽  
Author(s):  
P. R. Kvietys ◽  
R. H. Gallavan ◽  
C. C. Chou
Keyword(s):  
Amino Acids ◽  
Blood Flow ◽  
Oleic Acid ◽  
Caproic Acid ◽  
Local Blood Flow ◽  
Vascular Effects ◽  
Bile Concentration ◽  
Anesthetized Dogs ◽  
Per Se

The role played by bile in postprandial intestinal hyperemia was examined by comparing the vascular effects of luminal placement of various nutrients with and without bile in situ jejunal segments of anesthetized dogs. The bile concentration was either 10 or 33% of that in the gallbladder. At these concentrations, bile per se in the jejunal lumen does not alter local blood flow. In the absence of bile, only glucose increased flow (+5% above control). With 10% bile, glucose and oleic acid increased flow by 10 and 24%, whereas with 33% bile, glucose, oleic acid, caproic acid, and amino acids increased flow by 22, 21, 12, and 12% above control, respectively. Triolein increased flow only after digestion by pancreatic enzymes and mixing with bile. Dipeptides did not alter flow with or without bile. Thus, bile plays an important role in postprandial intestinal hyperemia because it potentiates the glucose-induced hyperemia and because only in its presence can oleic acid, amino acids, caproic acid, and digested triolein increase intestinal blood flow.

The silk tuft web decorations of the orb-weaver Gasteracantha cancriformis : testing the prey attraction and the web advertisement hypotheses

Behaviour ◽  
2008 ◽  
Vol 145 (3) ◽  
pp. 277-295 ◽  
Author(s):  
Felipe Gawryszewski ◽  
Paulo Motta
Keyword(s):  
Drosophila Melanogaster ◽  
Foraging Success ◽  
Uv Reflectance ◽  
Web Advertisement ◽  
Orb Web ◽  
Orb Web Spiders ◽  
Large Animals ◽  
And Control ◽  
The Web ◽  
Prey Attraction

AbstractSeveral orb-web spiders build conspicuous decorations in their webs. The prey attraction hypothesis proposes that decorations increase spider foraging success by attracting prey, and that attraction is linked to UV reflectance. Alternatively, the web advertisement hypothesis proposes that decorations are a signal that advertises the presence of the web to large animals. We tested both hypotheses for the web silk tufts of Gasteracantha cancriformis. Even though tufts are UV reflective, we did not find support for the prey attraction hypothesis. In the field, when webs with tufts painted black and control webs were compared, there were no differences in the number of prey captured, number of damaged areas in webs and type of prey captured. In the laboratory, Drosophila melanogaster did not demonstrate preference for tufted silk lines versus non-tufted silk lines. Our data also did not give support for the web advertisement hypothesis. The proportion of web destruction was similar between web with tufts painted black and control webs during four days of experimentation. Therefore, two of the most favoured hypotheses that attempt to explain decorations do not apply for web silk tufts in our study system. Instead we propose that silk tufts might be an aposematic signal.

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