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Université de Fribourg

Neuronal inputs and outputs of aging and longevity

Alcedo, Joy ; Flatt, Thomas ; Pasyukova, Elena G.

In: Frontiers in Genetics, 2013, vol. 4, p. -

An animal’s survival strongly depends on its ability to maintain homeostasis in response to the changing quality of its external and internal environment. This is achieved through intracellular and intercellular communication within and among different tissues. One of the organ systems that plays a major role in this communication and the maintenance of homeostasis is the nervous system....

Université de Fribourg

Winter weather affects asp viper Vipera aspis population dynamics through susceptible juveniles

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

In: Oikos, 2005, vol. 110 (1), p. 55

Detailed studies on mammals and birds have shown that the effects of climate variation on population dynamics often depend on population composition, because weather affects different subsets of a population differently. It is presently unknown whether this is also true for ectothermic animals such as reptiles. Here we show such an interaction between weather and demography for an ectothermic...

Université de Fribourg

Aminergic signaling controls ovarian dormancy in drosophila

Andreatta, Gabriele ; Kyriacou, Charalambos P. ; Flatt, Thomas ; Costa, Rodolfo

In: Scientific Reports, 2018, vol. 8, no. 1, p. 2030

In response to adverse environmental conditions many organisms from nematodes to mammals deploy a dormancy strategy, causing states of developmental or reproductive arrest that enhance somatic maintenance and survival ability at the expense of growth or reproduction. Dormancy regulation has been studied in C. elegans and in several insects, but how neurosensory mechanisms act to relay ...

Université de Fribourg

dSir2 and Dmp53 interact to mediate aspects of CR‐dependent life span extension in D. melanogaster

Bauer, Johannes H. ; Morris, Siti Nur Sarah ; Chang, Chenguyi ; Flatt, Thomas ; Wood, Jason G. ; Helfand, Stephen L.

In: Aging, 2009, vol. 1, no. 1, p. 38-48

Calorie Restriction (CR) is a well established method of extending life span in a variety of organisms. In the fruit fly D. melanogaster, CR is mediated at least in part by activation of dSir2. In mammalian systems, one of the critical targets of Sir2 is the tumor suppressor p53. This deacetylation of p53 by Sir2 leads to inhibition of p53's transcriptional activity. We have recently shown that...

Université de Fribourg

What is metamorphosis?

Bishop, C. D. ; Erezyilmaz, D. F. rsity ; Flatt, Thomas ; Georgiou, C. D. ; Hadfield, M. G. ; Heyland, A. ; Hodin, J. ; Jacobs, M. W. ; Malakova, S. A. ; Pires, A. ; Reitzel, A. M. ; Santagata, S. ; Tanaka, K. ; Youson, J. H.

In: Integrative and Comparative Biology, 2006, vol. 46, no. 6, p. 655–661

Metamorphosis (Gr. meta- “change” + morphe “form”) as a biological process is generally attributed to a subset of animals: most famously insects and amphibians, but some fish and many marine invertebrates as well. We held a symposium at the 2006 Society for Integrative and Comparative Biology (SICB) annual meeting in Orlando, FL (USA) to discuss metamorphosis in a comparative context....

Université de Fribourg

Aging and Its Demographic Measurement

Bronikowski, Anne M. ; Flatt, Thomas

In: Nature Education Knowledge, 2010, vol. 1, no. 12, p. 1-6

This case study highlights the general issues raised earlier. First, that maximum lifespan is not an easily obtainable metric. Specifically, it is unambiguous in the sense that once the last animal dies, it is most definitely dead. But to estimate the variance in maximum lifespan, many replicate populations would need to be followed for each treatment group (with each replicate providing a single...

Université de Fribourg

The diversity of population responses to environmental change

Colchero, Fernando ; Jones, Owen R. ; Conde, Dalia A. ; Hodgson, David ; Zajitschek, Felix ; Schmidt, Benedikt R. ; Malo, Aurelio F. ; Alberts, Susan C. ; Becker, Peter H. ; Bouwhuis, Sandra ; Bronikowski, Anne M. ; Vleeschouwer, Kristel M. ; Delahay, Richard J. ; Dummermuth, Stefan ; Fernández‐Duque, Eduardo ; Frisenvænge, John ; Hesselsøe, Martin ; Larson, Sam ; Lemaître, Jean‐François ; McDonald, Jennifer ; Miller, David A.W. ; O'Donnell, Colin ; Packer, Craig ; Raboy, Becky E. ; Reading, Chris J. ; Wapstra, Erik ; Weimerskirch, Henri ; While, Geoffrey M. ; Baudisch, Annette ; Flatt, Thomas ; Coulson, Tim ; Gaillard, Jean‐Michel

In: Ecology Letters, 2019, p. -

The current extinction and climate change crises pressure us to predict population dynamics with ever‐greater accuracy. Although predictions rest on the well‐advanced theory of age‐structured populations, two key issues remain poorly explored. Specifically, how the age‐dependency in demographic rates and the year‐to‐year interactions between survival and fecundity affect...

Université de Fribourg

Hormonal modulation of larval begging and growth in the burying beetle Nicrophorus vespilloides

Crook, Tara C. ; Flatt, Thomas ; Smiseth, Per T.

In: Animal behaviour, 2008, vol. 75, no. 1, p. 71-77

Recent studies on birds show that two steroid hormones, testosterone and corticosterone, stimulate nestling begging and growth. Here, we seek to investigate whether juvenile hormone, a major regulatory insect hormone, has similar effects on larval begging and growth in insects. To this end, we experimentally elevated larval juvenile hormone levels by topical application of methoprene, a potent...

Université de Fribourg

An inversion supergene in Drosophila underpins latitudinal clines in survival traits

Durmaz, Esra ; Benson, Clare ; Kapun, Martin ; Schmidt, Paul ; Flatt, Thomas

In: Journal of Evolutionary Biology, 2018, vol. 31, no. 9, p. 1354–1364

Chromosomal inversions often contribute to local adaptation across latitudinal clines, but the underlying selective mechanisms remain poorly understood. We and others have previously shown that a clinal inversion polymorphism in Drosophila melanogaster, In(3R)Payne, underpins body size clines along the North American and Australian east coasts. Here, we ask whether this polymorphism also...