755 research outputs found
Nonadditive Genetic Effects in Animal Behavior
Heritabilities, commonly used to predict evolutionary potential, are notoriously low for behaviors. Apart from strong contributions of environmental variance in reducing heritabilities, the additive genetic components can be very low, especially when they are camouflaged by nonadditive genetic effects. We first report the heritabilities of courtship traits in founderâflush and control populations of the housefly (Musca domestica L.). We estimated the heritability of each male and female display through the regression of the courtships involving daughters and sons (with randomly selected mates) onto the âmidparentalâ courtship values of their parents. Overall, the average heritability was significantly higher for the parentâdaughter assays than for the parentâson assays. We attributed the low (even negative) heritabilities to genotypeâbyâenvironment interactions whereby the maleâs behavior is influenced by the âenvironmentâ of his mating partnerâs preferences for the display, generating epistasis through indirect genetic effects. Moreover, bottlenecked lines had up to 800% of the heritability of the controls, suggesting âconversionâ of additive genetic variance from nonadditive components. Second, we used lineâcross assays on separate populations that had been selected for divergence in mating behavior to identify dominance and epistasis through heterosis and outbreeding depression in courtship. Finally, our literature review confirms the prevalence of such low heritabilities (i.e., a conservative mean of 0.38) and nonadditive genetics in other behavioral repertoires (64% of the studies). We conclude that animal behavior is especially prone to the gamut of quantitative genetic complexities that can result in negative heritabilities, negative selection responses, inbreeding depression, conversion, heterosis, and outbreeding depression
NF-kB functions in synaptic signaling and behavior
Ca^(2+)-regulated gene transcription is essential to diverse physiological processes, including the adaptive plasticity associated with learning. We found that basal synaptic input activates the NF-kB transcription factor by a pathway requiring the Ca^(2+)/calmodulin-dependent kinase CaMKII and local submembranous Ca^(2+) elevation. The p65:p50 NF-kB form is selectively localized at synapses; p65-deficient mice have no detectable synaptic NF-kB. Activated NF-kB moves to the nucleus and could directly transmute synaptic signals into altered gene expression. Mice lacking p65 show a selective learning deficit in the spatial version of the radial arm maze. These observations suggest that long-term changes to adult neuronal function caused by synaptic stimulation can be regulated by NF-kB nuclear translocation and gene activation
Electronic sculpting of ligand-GPCR subtype selectivity:the case of angiotensin II
GPCR subtypes possess distinct functional
and pharmacological profiles,
and thus development of subtype-selective ligands has immense therapeutic
potential. This is especially the case for the angiotensin receptor
subtypes AT1R and AT2R, where a functional negative control has been
described and AT2R activation highlighted as an important cancer drug
target. We describe a strategy to fine-tune ligand selectivity for
the AT2R/AT1R subtypes through electronic control of ligand aromatic-prolyl
interactions. Through this strategy an AT2R high affinity (<i>K</i><sub>i</sub> = 3 nM) agonist analogue that exerted 18,000-fold
higher selectivity for AT2R versus AT1R was obtained. We show that
this compound is a negative regulator of AT1R signaling since it is
able to inhibit MCF-7 breast carcinoma cellular proliferation in the
low nanomolar range
Atmospheric stilling offsets the benefits from reduced nutrient loading in a large shallow lake
As part of a global phenomenon, a 30% decrease in average wind speed since 1996 in southern Estonia
together with more frequent easterly winds resulted in 47% decrease in bottom shear stress in the large
(270 km2), shallow (mean depth 2.8 m), and eutrophic Lake VÔrtsjÀrv. Following a peak in eutrophication pressure
in the 1970sâ80s, the concentrations of total nutrients were declining. Nonmetric Multidimensional Scaling
(NMDS) ordination of a 54-year phytoplankton community composition time-series (1964â2017) revealed
three distinct periods with breaking points coinciding with changes in wind and/or water level. Contrary to
expectations, we detected no decrease in optically active substances that could be related to wind stilling,
whereas phytoplankton biomass showed an increasing trend despite reduced nutrient levels. Here we show how
opening of the âlight niche,â caused by declining amount of suspended sediments, was capitalized and filled by
the light-limited phytoplankton community. We suggest that wind stilling is another global factor, complementary
to climate warming that counteracts eutrophication mitigation in lakes and may provide a challenge to
assessment of the lake ecological status.Main financial support for EMU: European Unionâs Horizon 2020 research and innovation programme Under the Marie SkĆodowska-Curie Action, Innovative Training Networks, European Joint Doctorates.Project name, acronym and grant number: Management of climatic extreme events in lakes and reservoirs for the protection of ecosystem services, MANTEL, grant agreement No 722518.Publication date and, if applicable, length of embargo period: Published as Early View on 07.10.2019, no embargo period.Main financial support for EMU: European Unionâs Horizon 2020 research and innovation programme Under the Marie SkĆodowska-Curie Action, Innovative Training Networks, European Joint Doctorate
The German Miracle Keeps Running: How Germany's Hidden Champions Stay Ahead in the Global Economy
Despite mediocre macro-economic performance of the German economy, German companies are successful players in global trade. This article explores the strategies of one of the pillars of this export success, the Hidden Champions, Our empirical analysis focuses on leading medium size companies identified by Hermann Simon in the early 1990s, and investigates their long-term progress over one decade. We show that these companies continue to prosper with family ownership combined with professional external management, strategies of market leadership in global niches and a persistent focus on operational effectiveness. Scholars and business leaders, in particular of companies based in other high-cost countries, therefore ought to consider German companies as source for lessons on how to succeed in the global economy
Author correction : a global database for metacommunity ecology, integrating species, traits, environment and space
Correction to: Scientific Data https://doi.org/10.1038/s41597-019-0344-7, published online 08 January 202
Author correction : a global database for metacommunity ecology, integrating species, traits, environment and space
Correction to: Scientific Data https://doi.org/10.1038/s41597-019-0344-7, published online 08 January 202
- âŠ