scholarly journals Gene expression in the phenotypically plastic Arctic charr (Salvelinus alpinus): A focus on growth and ossification at early stages of development

2018 ◽  
Vol 21 (1) ◽  
pp. 16-30 ◽  
Author(s):  
Samantha V. Beck ◽  
Katja Räsänen ◽  
Ehsan P. Ahi ◽  
Bjarni K. Kristjánsson ◽  
Skúli Skúlason ◽  
...  
Keyword(s):  
Gene Expression ◽  
Salvelinus Alpinus ◽  
Arctic Charr ◽  
Stages Of Development ◽  
Early Stages

Effects of soybean and sunflower meals on the growth, feed utilization, and gene expression in two Canadian strains of juvenile Arctic charr (Salvelinus alpinus)

Aquaculture ◽  
2017 ◽  
Vol 481 ◽  
pp. 191-201 ◽  
Author(s):  
Amanda A. Smith ◽  
André Dumas ◽  
Rodrigue Yossa ◽  
Kenneth E. Overturf ◽  
Dominique P. Bureau
Keyword(s):  
Gene Expression ◽  
Salvelinus Alpinus ◽  
Arctic Charr ◽  
Feed Utilization

scholarly journals Robustness of the Dorsal morphogen gradient with respect to morphogen dosage

2019 ◽  
Author(s):  
Hadel Al Asafen ◽  
Prasad U. Bandodkar ◽  
Sophia Carrell-Noel ◽  
Gregory T. Reeves
Keyword(s):  
Gene Expression ◽  
Expression Patterns ◽  
Positional Information ◽  
The Body ◽  
Morphogen Gradient ◽  
Gene Expression Patterns ◽  
Facilitated Diffusion ◽  
Uniform Field ◽  
Stages Of Development ◽  
Early Stages

AbstractIn multicellular organisms, the timing and placement of gene expression in a developing tissue assigns the fate of each cell in the embryo in order for a uniform field of cells to differentiate into a reproducible pattern of organs and tissues. This positional information is often achieved through the action of spatial gradients of morphogens. Spatial patterns of gene expression are paradoxically robust to variations in morphogen dosage, given that, by definition, gene expression must be sensitive to morphogen concentration. In this work we investigate the robustness of the Dorsal/NF-κB signaling module with respect to perturbations to the dosage of maternally-expressed dorsal mRNA. The Dorsal morphogen gradient patterns the dorsal-ventral axis of the early Drosophila embryo, and we found that an empirical description of the Dorsal gradient is highly sensitive to maternal dorsal dosage. In contrast, we found experimentally that gene expression patterns are highly robust. Although the components of this signaling module have been characterized in detail, how their function is integrated to produce robust gene expression patterns to variations in the dorsal maternal dosage is still unclear. Therefore, we analyzed a mechanistic model of the Dorsal signaling module and found that Cactus, a cytoplasmic inhibitor for Dorsal, must be present in the nucleus for the system to be robust. Furthermore, active Toll, the receptor that dissociates Cactus from Dorsal, must be saturated. Finally, the vast majority of robust descriptions of the system require facilitated diffusion of Dorsal by Cactus. Each of these three recently-discovered mechanisms of the Dorsal module are critical for robustness. Our work highlights the need for quantitative understanding of biophysical mechanisms of morphogen gradients in order to understand emergent phenotypes, such as robustness.Author SummaryThe early stages of development of an embryo are crucial for laying the foundation of the body plan. The blueprint of this plan is encoded in long-range spatial protein gradients called morphogens. This positional information is then interpreted by nuclei that begin to differentiate by expressing different genes. In fruit fly embryos, the Dorsal morphogen forms a gradient along the dorsal-ventral axis, with a maximum at the ventral midline. This gradient, and the resulting gene expression patterns are extraordinarily robust to variations in developmental conditions, even during early stages of development. Since positional information is interpreted in terms of concentration of the morphogen, one would expect that doubling or halving dosage would result in disastrous consequences for the embryo. However, we observed that development remains robust. We quantified the effect of dosage by experimentally measuring the boundaries of 2 genes, - sna and sog, expressed along the DV axis and found that variation in the boundaries of these genes was minimal, across embryos with different dosages of Dl. We then used a mathematical model to discern components of the Dl system responsible for buffering the effects of dosage and found three specific mechanisms – deconvolution, Toll saturation and shuttling

Impaired Swimming Performance of Acid-exposed Arctic Charr, Salvelinus Alpinus L.

1988 ◽  
Vol 23 (2) ◽  
pp. 301-307 ◽  
Author(s):  
L.A. Hunter ◽  
E. Scherer
Keyword(s):  
Dose Response ◽  
Salvelinus Alpinus ◽  
Arctic Charr ◽  
Swimming Performance ◽  
Control Level ◽  
Ventilation Rates

Abstract Arctic charr (Salvelinus alpinus L.) were exposed to five levels of acidity between pH 6 and pH 3.8. Swimming performance as determined by critical swimming speeds was 67.5 cm · sࢤ1 or 4.4 body lengths per second for untreated fish (pH 7.8). Performance declined sharply below pH 4.5; at pH 3.8 it was reduced by 35% after 7 days of exposure. Tailbeat frequencies and ventilation rates showed no dose-response effects. At swimming speeds between 20 and 50 cm · sࢤ1, ventilation rates at all levels of acidity were higher than at the control level.

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