Affiner les résultats

Collection spécifique

Langue

Université de Fribourg

Mark-recapture Estimates of Survival in Populations of the Asp Viper, Vipera aspis aspis

Flatt, Thomas ; Dummermuth, Stefan ; Anholt, Bradley R.

In: Journal of Herpetology, 1997, vol. 31, no. 4, p. 558-564

We estimated th eannual survivorship of two populations of the asp viper, Vipera aspis aspis, by recapturing known dult individuals in the field over six and nine years respectively. The snakes at the two study sites in th eJura mountains of northwestern Switzerland were active between mid-March and mid-October. Vispera a. aspis is easily captured by hand, has individually recognizable marks and...

Université de Fribourg

Reproduction, fat metabolism, and life span: what is the connection?

Hansen, Malene ; Flatt, Thomas ; Aguilaniu, Hugo

In: Cell Metabolism, 2013, vol. 17, no. 1, p. 10–19

Reduced reproduction is associated with increased fat storage and prolonged life span in multiple organisms, but the underlying regulatory mechanisms remain poorly understood. Recent studies in several species provide evidence that reproduction, fat metabolism, and longevity are directly coupled. For instance, germline removal in the nematode Caenorhabditis elegans promotes longevity in part...

Université de Fribourg

Life-history evolution and the polyphenic regulation of somatic maintenance and survival

Flatt, Thomas ; Amdam, Gro V. ; Kirkwood, Thomas B. L. ; Omholt, Stig W.

In: The Quarterly Review of Biology, 2013, vol. 88, no. 3, p. 185–218

Here we discuss life-history evolution from the perspective of adaptive phenotypic plasticity, with a focus on polyphenisms for somatic maintenance and survival. Polyphenisms are adaptive discrete alternative phenotypes that develop in response to changes in the environment. We suggest that dauer larval diapause and its associated adult phenotypes in the nematode (Caenorhabditis elegans),...

Université de Fribourg

Ecdysone triggered PGRP‐LC expression controls Drosophila innate immunity

Rus, Florentina ; Flatt, Thomas ; Tong, Mei ; Aggarwal, Kamna ; Okuda, Kendi ; Kleino, Anni ; Yates, Elisabeth ; Tatar, Marc ; Silverman, Neal

In: The EMBO Journal, 2013, vol. 32, no. 11, p. 1626–1638

Throughout the animal kingdom, steroid hormones have been implicated in the defense against microbial infection, but how these systemic signals control immunity is unclear. Here, we show that the steroid hormone ecdysone controls the expression of the pattern recognition receptor PGRP‐LC in Drosophila, thereby tightly regulating innate immune recognition and defense against bacterial...

Université de Fribourg

A Bit of Sex Stabilizes Host+Parasite Dynamics

Flatt, Thomas ; Maire, Nicolas ; Doebeli, Michael

In: Journal of Theoretical Biology, 2001, vol. 212, no. 3, p. 345-354

To date, only a few studies have focused on the effects of sex on population dynamics. Previous models have typically found that sexual reproduction dampens population fluctuations. Although asexual and sexual reproduction are just the two endpoints along a continuum of varying rates of sex, previous work has ignored the effects of intermediate degrees of sex on population dynamics. Here we study...

Université de Fribourg

Genome-wide patterns of latitudinal differentiation among populations of Drosophila melanogaster from North America

Fabian, Daniel K. ; Kapun, Martin ; Nolte, Viola ; Kofler, Robert ; Schmidt, Paul S. ; Schlötterer, Christian ; Flatt, Thomas

In: Molecular Ecology, 2012, vol. 21, no. 19, p. 4748–4769

Understanding the genetic underpinnings of adaptive change is a fundamental but largely unresolved problem in evolutionary biology. Drosophila melanogaster, an ancestrally tropical insect that has spread to temperate regions and become cosmopolitan, offers a powerful opportunity for identifying the molecular polymorphisms underlying clinal adaptation. Here, we use genome‐wide next‐...

Université de Fribourg

Adaptation of Drosophila to a novel laboratory environment reveals temporally heterogeneous trajectories of selected alleles

Orozco‐Terwengel, Pablo ; Kapun, Martin ; Nolte, Viola ; Kofler, Robert ; Flatt, Thomas ; Schlötterer, Christian

In: Molecular Ecology, 2012, vol. 21, no. 20, p. 4931–4941

The genomic basis of adaptation to novel environments is a fundamental problem in evolutionary biology that has gained additional importance in the light of the recent global change discussion. Here, we combined laboratory natural selection (experimental evolution) in Drosophila melanogaster with genome‐wide next generation sequencing of DNA pools (Pool‐Seq) to identify alleles that are...

Université de Fribourg

Increased temperature disrupts the biodiversity–ecosystem functioning relationship

Parain, Elodie C. ; Rohr, Rudolf P. ; Gray, Sarah M. ; Bersier, Louis-Félix

In: The American Naturalist, 2018, vol. 193, no. 2, p. 227–239

Gaining knowledge of how ecosystems provide essential services to humans is of primary importance, especially with the current threat of climate change. Yet little is known about how increased temperature will impact the biodiversity–ecosystem functioning (BEF) relationship. We tackled this subject theoretically and experimentally. We developed a BEF theory based on mechanistic population ...

Université de Fribourg

A dedicated target capture approach reveals variable genetic markers across micro- and macro-evolutionary time scales in palms

de La Harpe, Marylaure ; Hess, Jaqueline ; Loiseau, Oriane ; Salamin, Nicolas ; Lexer, Christian ; Paris, Margot

In: Molecular Ecology Resources, 2019, p. -

Understanding the genetics of biological diversification across micro‐ and macro‐ evolutionary time scales is a vibrant field of research for molecular ecologists as rapid advances in sequencing technologies promise to overcome former limitations. In palms, an emblematic, economically and ecologically important plant family with high diversity in the tropics, studies of diversification at...