Université de Fribourg

Genomic evidence for adaptive inversion clines in Drosophila melanogaster

Kapun, Martin ; Fabian, Daniel K. ; Goudet, Jérôme ; Flatt, Thomas

In: Molecular Biology and Evolution, 2016, vol. 33, no. 5, p. 1317–1336

Clines in chromosomal inversion polymorphisms—presumably driven by climatic gradients—are common but there is surprisingly little evidence for selection acting on them. Here we address this long-standing issue in Drosophila melanogaster by using diagnostic single nucleotide polymorphism (SNP) markers to estimate inversion frequencies from 28 whole-genome Pool-seq samples collected from 10...

Université de Fribourg

Drosophila germ-line modulation of insulin signaling and lifespan

Flatt, Thomas ; Min, Kyung-Jin ; D'Alterio, Cecilia ; Villa-Cuesta, Eugenia ; Cumbers, John ; Lehmann, Ruth ; Jones, D. Leanne ; Tatar, Marc

In: Proceedings of the National Academy of Sciences of the United States of America, 2008, vol. 105, no. 17, p. 6368–6373

Ablation of germ-line precursor cells in Caenorhabditis elegans extends lifespan by activating DAF-16, a forkhead transcription factor (FOXO) repressed by insulin/insulin-like growth factor (IGF) signaling (IIS). Signals from the gonad might thus regulate whole-organism aging by modulating IIS. To date, the details of this systemic regulation of aging by the reproductive system are not...

Université de Fribourg

Genomics of clinal variation in Drosophila: disentangling the interactions of selection and demography

Flatt, Thomas

In: Molecular Ecology, 2016, vol. 25, no. 5, p. 1023–1026

Clines in phenotypes and genotype frequencies across environmental gradients are commonly taken as evidence for spatially varying selection. Classical examples include the latitudinal clines in various species of Drosophila, which often occur in parallel fashion on multiple continents. Today, genomewide analysis of such clinal systems provides a fantastic opportunity for unravelling the...

Université de Fribourg

Endocrine uncoupling of the trade-off between reproduction and somatic maintenance in eusocial insects

Rodrigues, Marisa A. ; Flatt, Thomas

In: Current Opinion in Insect Science, 2016, vol. 16, p. 1–8

In most animals reproduction trades off with somatic maintenance and survival. Physiologically this trade-off is mediated by hormones with opposite effects on reproduction and maintenance. In many insects, this regulation is achieved by an endocrine network that integrates insulin-like/IGF-1 signaling (IIS), juvenile hormone (JH), and the yolk precursor vitellogenin (Vg) (or, more generally,...

Université de Fribourg

Spatially varying selection shapes life history clines among populations of Drosophila melanogaster from sub-Saharan Africa

Fabian, D. K. ; Lack, J. B. ; Mathur, V. ; Schlötterer, C. ; Schmidt, P. S. ; Pool, J. E. ; Flatt, Thomas

In: Journal of Evolutionary Biology, 2015, vol. 28, no. 4, p. 826–840

Clines in life history traits, presumably driven by spatially varying selection, are widespread. Major latitudinal clines have been observed, for example, in Drosophila melanogaster, an ancestrally tropical insect from Africa that has colonized temperate habitats on multiple continents. Yet, how geographic factors other than latitude, such as altitude or longitude, affect life history in this...

Université de Fribourg

Still Pondering an Age-Old Question

Flatt, Thomas ; Promislow, Daniel E. L.

In: Science, 2007, vol. 318, p. 1255-1256

A theory of trade-offs to explain why we age has spurred 50 years of interdisciplinary research in evolution and molecular genetics.

Université de Fribourg

Paying the costs of reproduction

Flatt, Thomas

In: eLife, 2015, vol. 4, p. e09556

When a female fly mates it produces a hormone that increases the size of its midgut and enhances fat metabolism in order to provide the energy needed for reproduction.

Université de Fribourg

Counting calories in Drosophila diet restriction

Min, Kyung-Jin ; Flatt, Thomas ; Kulaots, Indrek ; Tatar, Marc

In: Experimental Gerontology, 2006, vol. 42, no. 3, p. 247-251

The extension of life span by diet restriction in Drosophila has been argued to occur without limiting calories. Here we directly measure the calories assimilated by flies when maintained on full- and restricted-diets. We find that caloric intake is reduced on all diets that extend life span. Flies on low-yeast diet are long-lived and consume about half the calories of flies on high-yeast diets,...

Université de Fribourg

Similarities and differences in altitudinal versus latitudinal variation for morphological traits in Drosophila melanogaster

Klepsatel, Peter ; Gáliková, Martina ; Huber, Christian D. ; Flatt, Thomas

In: Evolution, 2014, vol. 68, no. 5, p. 1385–1398

Understanding how natural environments shape phenotypic variation is a major aim in evolutionary biology. Here, we have examined clinal, likely genetically based variation in morphology among 19 populations of the fruit fly (Drosophila melanogaster) from Africa and Europe, spanning a range from sea level to 3000 m altitude and including locations approximating the southern and northern range...

Université de Fribourg

Inference of chromosomal inversion dynamics from Pool-Seq data in natural and laboratory populations of Drosophila melanogaster

Kapun, Martin ; van Schalkwyk, Hester ; McAllister, Bryant ; Flatt, Thomas ; Schlötterer, Christian

In: Molecular Ecology, 2014, vol. 23, no. 7, p. 1813–1827

Sequencing of pools of individuals (Pool‐Seq) represents a reliable and cost‐effective approach for estimating genome‐wide SNP and transposable element insertion frequencies. However, Pool‐Seq does not provide direct information on haplotypes so that, for example, obtaining inversion frequencies has not been possible until now. Here, we have developed a new set of diagnostic marker...