Life implies change. And this holds true for genes as well. Organisms require a flexible genome in order to adapt to changes in the local environment.
Christian Schlötterer and his team from the Institute for Population Genetics at the University of Veterinary Medicine, Vienna study the genomes of entire populations. The scientists want to know why individuals differ from each other and how these differences are encoded in the DNA.
Christian Schlötterer and his colleagues are searching for variation in the genomes of fruitflies.
Photo: Michael Bernkopf / Vetmeduni Vienna
In two review papers published in the journals Nature Reviews Genetics and Heredity, they discuss why DNA sequencing of entire groups can be an efficient and cost-effective way to answer these questions.
DNA analysis has become increasingly efficient and cost-effective since the human genome was first fully sequenced in the year 2001. Sequencing a complete genome, however, still costs around US$1,000. Sequencing the genetic code of hundreds of individuals would therefore be very expensive and time-consuming. In particular for non-human studies, researchers very quickly hit the limit of financial feasibility.
Sequencing groups instead of individuals
The solution to this problem is pool sequencing (Pool-Seq). Schlötterer and his team sequence entire groups of fruit flies (Drosophila melanogaster) at once instead of carrying out many individual sequencing reactions. While the resulting genetic information cannot be attributed to a single individual, the complete data set still provides important genetic information about the entire population.
In the two publications, Schlötterer and colleagues discuss the breadth of questions that can be addressed by Pool-Seq.
Searching for the building blocks of evolution
In order to understand how organisms react to changes in the local environment, the genomes of entire populations can be analysed using Pool-Seq, before and after changed conditions. To do so, the researchers use the method of evolve and resequence (E&R). Schlötterer received an ERC Advanced Grant for this approach in 2012. E&R is a method in which the DNA of a group of individuals is sequenced. After exposing the descendents of this group for several generations to a certain stress, such as high temperature, extreme cold or UV radiation, and the evolved group is then sequenced again. A comparison of the two data sets uncovers genes that have changed in response to the selective stress. The approach makes it possible, for example, to filter out the genes that are involved in a darker pigmentation in response to UV radiation.
“Using this principle, we can perform evolution experiments at high speed. We are using this method to address a broad range of questions, ranging from the identification of genes which influence aging, or genes protecting against diseases and finally to understand the genetic changes which reduce the impact of climate change,” Schlötterer explains.
Uncovering the genetics of aging and disease resistance
The evolve-and-resequence approach also makes it also possible to filter out the genes that regulate aging. This process involves selecting flies from a population, repeatedly over generations, that reach an especially old age. Several generations later, the researchers then compare the genomes of the “Methuselah” flies with those from normally aging flies in order to extract the genes that are involved in the aging process. This method also works to locate genes that provide resistance against certain diseases.
Bioinformatician and co-author, Robert Kofler, explains: “We are dealing with genetic change processes and are searching for variations in the genomes. The variations can help us to understand how evolution works.”
Population geneticists trained in Vienna
Schlötterer heads the “Vienna Graduate School of Population Genetics” hosted by the University of Veterinary Medicine, Vienna. The doctoral program fills the gap between theoretical and experimental population genetics. 22 PhD students are currently conducting research in Vienna in the field of theoretical and experimental population genetics, bioinformatics, and statistics. http://www.popgen-vienna.at
The article „Sequencing pools of individuals – mining genome-wide polymorphism data without big funding” by Christian Schlötterer, Taymond Tobler, Robert Kofler and Viola Nolte was published in the journal Nature Reviews Genetics. DOI:10.1038/nrg3803
The article “Combining experimental evolution with next-generation sequencing: a powerful tool to study adaptation from standing genetic variation” by Christian Schlötterer, Robert Kofler, E. Versace, Raymond Tobler and S. U. Franssen was published in the journal Heredity. DOI:HDY.2014.86
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 1 25077-4300
Science Communication / Public Relations
University of Veterinary Medicine Vienna (Vetmeduni Vienna)
T +43 1 25077-1153
Dr. Susanna Kautschitsch | idw - Informationsdienst Wissenschaft
Link Discovered between Immune System, Brain Structure and Memory
26.04.2017 | Universität Basel
Researchers develop eco-friendly, 4-in-1 catalyst
25.04.2017 | Brown University
More and more automobile companies are focusing on body parts made of carbon fiber reinforced plastics (CFRP). However, manufacturing and repair costs must be further reduced in order to make CFRP more economical in use. Together with the Volkswagen AG and five other partners in the project HolQueSt 3D, the Laser Zentrum Hannover e.V. (LZH) has developed laser processes for the automatic trimming, drilling and repair of three-dimensional components.
Automated manufacturing processes are the basis for ultimately establishing the series production of CFRP components. In the project HolQueSt 3D, the LZH has...
Reflecting the structure of composites found in nature and the ancient world, researchers at the University of Illinois at Urbana-Champaign have synthesized thin carbon nanotube (CNT) textiles that exhibit both high electrical conductivity and a level of toughness that is about fifty times higher than copper films, currently used in electronics.
"The structural robustness of thin metal films has significant importance for the reliable operation of smart skin and flexible electronics including...
The nearby, giant radio galaxy M87 hosts a supermassive black hole (BH) and is well-known for its bright jet dominating the spectrum over ten orders of magnitude in frequency. Due to its proximity, jet prominence, and the large black hole mass, M87 is the best laboratory for investigating the formation, acceleration, and collimation of relativistic jets. A research team led by Silke Britzen from the Max Planck Institute for Radio Astronomy in Bonn, Germany, has found strong indication for turbulent processes connecting the accretion disk and the jet of that galaxy providing insights into the longstanding problem of the origin of astrophysical jets.
Supermassive black holes form some of the most enigmatic phenomena in astrophysics. Their enormous energy output is supposed to be generated by the...
The probability to find a certain number of photons inside a laser pulse usually corresponds to a classical distribution of independent events, the so-called...
Microprocessors based on atomically thin materials hold the promise of the evolution of traditional processors as well as new applications in the field of flexible electronics. Now, a TU Wien research team led by Thomas Müller has made a breakthrough in this field as part of an ongoing research project.
Two-dimensional materials, or 2D materials for short, are extremely versatile, although – or often more precisely because – they are made up of just one or a...
20.04.2017 | Event News
18.04.2017 | Event News
03.04.2017 | Event News
26.04.2017 | Life Sciences
26.04.2017 | Physics and Astronomy
26.04.2017 | Earth Sciences