The phenotype of organisms is shaped by the interaction between environmental factors and their genetic constitution. A recent study by a team of population geneticists at the Vetmeduni Vienna shows that fruit flies live in a sort of genetic comfort zone at a specific temperature. The scientists found that, despite their underlying genetic differences, two separate strains of flies had a very similar gene expression pattern at 18°C. This effect of ‘canalization’, which has also been described in humans, allows organisms to continue to grow and develop stable even in the face of genetic and environmental stress. The results were published in the journal PLOS Genetics.
The information encoded in the DNA of an organism is not sufficient to determine the expression pattern of genes. This fact has been known even before the discovery of epigenetics, which refers to external modifications to the DNA that turn genes "on" or "off". These modifications do not change the DNA sequence, but instead, they affect how genes are expressed.
Another, less known mechanism called canalization keeps organisms robust despite genetic mutations and environmental stressors. If an organism experiences environmental or genetic perturbations during its development, such as extreme living conditions or genetic mutations, canalization acts as a way of buffering these disturbances. The organism remains stable and can continue to develop without recognizable changes.
A comfort zone in the fly genome
Christian Schlötterer at the Institute of Population Genetics and his colleagues studied the mechanism of canalisation in fruit flies. The researchers subjected two genetically distinct strains of fruit flies, Oregon and Samarkand, to different temperatures (13°C, 18°C, 23°C and 29°C). Subsequently, they analysed the variation in gene expression in response to the different temperatures. The results revealed a homogenous pattern of gene expression among the two strains at 18°C. No matter whether the flies were from the Oregon or to the Samarkand strain, their gene expression was almost indistinguishable.
“The flies’ genetic comfort zone appears to be located at 18°C. “As soon as the flies leave the comfort zone, move to either higher or lower temperatures, the gene expression of the two strains varies dramatically” Schlötterer explains.
Buffering the genotype
The effect of canalization was first described in 1942, when researchers pointed out that organisms remain stable in their external appearance despite different environmental circumstances or genetic mutations. This sort of developmental buffering helps to stabilize organismal growth.
“If an organism develops along the canalization pathway, or along the comfort zone, mutations can accumulate without being expressed. Once an organisms leaves the canalized range, those hidden genetic variations can be expressed and become visible. The phenomenon is called decanalization”, Schlötterer explains.
Decanalization as the origin of complex genetic disease
A publication by U.S. researcher Greg Gibson in the journal Nature (Paper-Link) proposes that diseases such as diabetes, asthma, depression and cardiovascular disease are the consequence of genetic decanalization. He describes how migration, diet, smoking, air pollution and psychological stress can lead to stress-mediated decanalization and therefore cause certain complex genetic diseases in humans.
“Genetic information alone does not determine whether we stay healthy or not. It is the complex interaction of environmental conditions and genetic variation that needs to be considered,” says Schlötterer.
The article „Temperature stress mediates decanalization and dominance of gene expression in Drosophila melanogaster”, by Jun Chen, Viola Nolte and Christian Schlötterer will be published on the 26th of February 2015 at 8 pm (CET) in the journal PLOS Genetics.
About the University of Veterinary Medicine, Vienna
The University of Veterinary Medicine, Vienna in Austria is one of the leading academic and research institutions in the field of Veterinary Sciences in Europe. About 1,300 employees and 2,300 students work on the campus in the north of Vienna which also houses five university clinics and various research sites. Outside of Vienna the university operates Teaching and Research Farms. http://www.vetmeduni.ac.at
Prof. Christian Schlötterer
Institute of Population Genetics
University of Veterinary Medicine Vienna (Vetmeduni Vienna)
T +43 676-3544155
Science Communication / Public Relations
University of Veterinary Medicine Vienna (Vetmeduni Vienna)
T +43 1 25077-1153
Dr. Susanna Kautschitsch | idw - Informationsdienst Wissenschaft
What happens in the cell nucleus after fertilization
06.12.2016 | Helmholtz Zentrum München - Deutsches Forschungszentrum für Gesundheit und Umwelt
Researchers uncover protein-based “cancer signature”
05.12.2016 | Universität Basel
In recent years, lasers with ultrashort pulses (USP) down to the femtosecond range have become established on an industrial scale. They could advance some applications with the much-lauded “cold ablation” – if that meant they would then achieve more throughput. A new generation of process engineering that will address this issue in particular will be discussed at the “4th UKP Workshop – Ultrafast Laser Technology” in April 2017.
Even back in the 1990s, scientists were comparing materials processing with nanosecond, picosecond and femtosesecond pulses. The result was surprising:...
Have you ever wondered how you see the world? Vision is about photons of light, which are packets of energy, interacting with the atoms or molecules in what...
A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.
Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...
In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.
“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...
The Max Planck Institute for Physics (MPP) is opening up a new research field. A workshop from November 21 - 22, 2016 will mark the start of activities for an innovative axion experiment. Axions are still only purely hypothetical particles. Their detection could solve two fundamental problems in particle physics: What dark matter consists of and why it has not yet been possible to directly observe a CP violation for the strong interaction.
The “MADMAX” project is the MPP’s commitment to axion research. Axions are so far only a theoretical prediction and are difficult to detect: on the one hand,...
16.11.2016 | Event News
01.11.2016 | Event News
14.10.2016 | Event News
06.12.2016 | Materials Sciences
06.12.2016 | Medical Engineering
06.12.2016 | Power and Electrical Engineering