Related Experiment Video
Updated: Jan 7, 2026
08:35
High Throughput Danio Rerio Energy Expenditure Assay
Published on: January 27, 2016
13.1K
Density-Dependent Expression of Epitranscriptomic, Stress and Appetite Regulating Genes in Atlantic Salmon
Morgane Frapin1, Laura Quispe1, Joana Troka1
1Organismal and Evolutionary Biology Research Program, Faculty of Biological and Environmental Sciences, University of Helsinki, Helsinki, Finland.
Molecular Ecology
|January 3, 2026
Summary
High-density conditions in Atlantic salmon juveniles alter gene expression in the hypothalamus, affecting stress and appetite regulation. These density-dependent changes are influenced by genetic factors and epitranscriptomic modifications.
Area of Science:
- * Aquatic Ecology
- * Molecular Biology
- * Genetics
Background:
- * Intraspecific competition, particularly density, significantly impacts fitness and life history dynamics in wild populations.
- * The precise physiological and molecular mechanisms underlying density-dependent responses remain largely unclear.
- * Replicating natural conditions in laboratory settings to study these responses is challenging.
Purpose of the Study:
- * To investigate the molecular mechanisms of density-related changes in the hypothalamus of Atlantic salmon juveniles.
- * To examine density-dependent gene expression in stress and appetite regulation pathways.
- * To explore the role of m6A RNA methylation and genotype-environment interactions in density responses.
Main Methods:
- * Atlantic salmon juveniles were reared in semi-wild conditions at two different densities.
- * Gene expression analysis focused on 12 genes related to appetite/stress and 16 genes involved in m6A RNA methylation.
- * Genotype-environment interactions were quantified for the vgll3 and six6 life-history loci.
Main Results:
- * Significant density-related differences were observed in the expression of genes controlling stress (corticotropin-releasing factors) and appetite (stimulators and inhibitors).
- * The expression patterns of m6A RNA methylation actors were also density-dependent.
- * The six6 locus interacted with density, influencing the expression of epitranscriptomic markers, including gene 'writers' and 'erasers'.
Conclusions:
- * An individual's response to population density in natural environments is a complex integration of stress, appetite, and epitranscriptomic pathways within the hypothalamus.
- * Functional divergence in gene paralogs suggests a role for genome duplication in shaping density responses.
- * Integrating molecular-level physiological data is crucial for understanding ecological processes affected by environmental changes like increased density.
Related Concept Videos
01:23Stringent Response in E. coli
257
Bacterial growth is closely tied to nutrient availability, with cells proliferating exponentially under favorable conditions and entering a stationary phase when resources become scarce. This transition is mediated by a regulatory mechanism known as the stringent response, which allows bacteria to adapt to nutrient deprivation by modulating gene expression and metabolic activity.During nutrient scarcity, intracellular amino acid levels decline. It results in the accumulation of uncharged tRNAs...
257
01:58Cell Specific Gene Expression
16.2K
Multicellular organisms contain a variety of structurally and functionally distinct cell types, but the DNA in all the cells originated from the same parent cells. The differences in the cells can be attributed to the differential gene expression. Liver cells, whose functions include detoxification of blood, production of bile to metabolize fats, and synthesis of proteins essential for metabolism, must express a specific set of genes to perform their functions. Gene expression also varies with...
16.2K
01:29Translational Regulation
503
Translational regulation in prokaryotes ensures efficient protein synthesis by controlling ribosome access to mRNA. This regulation is mediated by secondary RNA structures, including translational riboswitches, RNA thermometers, and small RNAs (sRNAs), which respond to intracellular and environmental signals to modulate gene expression.Translational RiboswitchesRiboswitches in the leader region of mRNAs can regulate translation by altering the accessibility of the Shine-Dalgarno (SD) sequence,...
503
01:23Regulation of Expression at Multiple Steps
1.3K
The gene expression in cells is regulated at different stages: (i) transcription, (ii) RNA processing, (iii) RNA localization, and (iv) translation. Transcriptional regulation is mediated by regulatory proteins such as transcription factors, activators, or repressors—these control gene expression by initiating or inhibiting the transcription of genes. Once a precursor or pre-mRNA is produced, it undergoes post-transcriptional modification, including 5' capping, splicing, and the...
1.3K
01:28Human Genetics
1.4K
Human genetics provides a profound framework for understanding the interplay between genetic predispositions and human psychology. At the heart of this discipline lies the study of how genes influence physical traits, behaviors, and susceptibility to diseases. Each person carries a unique genetic code that subtly or significantly shapes their psychological and behavioral landscape.
The complex relationship between genetics and psychology is observable through common biological components such...
The complex relationship between genetics and psychology is observable through common biological components such...
1.4K
01:30Regulation of Food Intake
2.2K
Short-term regulation of food intake primarily involves neural signals from the gastrointestinal (GI) tract, blood nutrient levels, and GI tract hormones. Communication between the gut and brain via vagal nerve fibers plays a significant role in evaluating the contents of the gut. Clinical studies have shown that protein ingestion produces a more prolonged response in these nerve fibers compared to an equivalent amount of glucose. Additionally, the activation of stretch receptors caused by GI...
2.2K