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...
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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...
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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...
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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...
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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,...
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In: BioEssays, 2007, vol. 29, no. 6, p. 536-548
Among all organisms, the size of each body part or organ scales with overall body size, a phenomenon called allometry. The study of shape and form has attracted enormous interest from biologists, but the genetic, developmental and physiological mechanisms that control allometry and the proportional growth of parts have remained elusive. Recent progress in our understanding of body‐size...
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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...
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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.
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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.
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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,...
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