ORCID Profile
0000-0001-8350-1203
Current Organisations
Los Alamos National Lab
,
Oak Ridge National Lab
,
Uppsala University
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Publisher: Public Library of Science (PLoS)
Date: 02-2011
Publisher: Wiley
Date: 18-03-2010
DOI: 10.1111/J.1558-5646.2010.00991.X
Abstract: Phenotypic plasticity is an important mechanism via which populations can respond to changing environmental conditions, but we know very little about how natural populations vary with respect to plasticity. Here we use random-regression animal models to understand the multivariate phenotypic and genetic patterns of plasticity variation in two key life-history traits, laying date and clutch size, using data from long-term studies of great tits in The Netherlands (Hoge Veluwe [HV]) and UK (Wytham Woods [WW]). We show that, while population-level responses of laying date and clutch size to temperature were similar in the two populations, between-in idual variation in plasticity differed markedly. Both populations showed significant variation in phenotypic plasticity (IxE) for laying date, but IxE was significantly higher in HV than in WW. There were no significant genotype-by-environment interactions (GxE) for laying date, yet differences in GxE were marginally nonsignificant between HV and WW. For clutch size, we only found significant IxE and GxE in WW but no significant difference between populations. From a multivariate perspective, plasticity in laying date was not correlated with plasticity in clutch size in either population. Our results suggest that generalizations about the form and cause of any response to changing environmental conditions across populations may be difficult.
Publisher: Springer Science and Business Media LLC
Date: 24-10-2019
DOI: 10.1038/S41598-019-51605-Y
Abstract: Hille’s (1971) seminal study of organic cation selectivity of eukaryotic voltage-gated sodium channels showed a sharp size cut-off for ion permeation, such that no ion possessing a methyl group was permeant. Using the prokaryotic channel, NaChBac, we found some similarity and two peculiar differences in the selectivity profiles for small polyatomic cations. First, we identified a erse group of minimally permeant cations for wildtype NaChBac, ranging in sizes from ammonium to guanidinium and tetramethylammonium and second, for both ammonium and hydrazinium, the charge-conserving selectivity filter mutation (E191D) yielded substantial increases in relative permeability (P X /P Na ). The relative permeabilities varied inversely with relative K d calculated from 1D Potential of Mean Force profiles (PMFs) for the single cations traversing the channel. Several of the cations bound more strongly than Na + , and hence appear to act as blockers, as well as charge carriers. Consistent with experimental observations, the E191D mutation had little impact on Na + binding to the selectivity filter, but disrupted the binding of ammonium and hydrazinium, consequently facilitating ion permeation across the NaChBac-like filter. We concluded that for prokaryotic sodium channels, a fine balance among filter size, binding affinity, occupancy, and flexibility seems to contribute to observed functional differences.
Publisher: MDPI AG
Date: 16-03-2015
Publisher: Springer Science and Business Media LLC
Date: 09-12-2019
DOI: 10.1038/S41598-019-55306-4
Abstract: An amendment to this paper has been published and can be accessed via a link at the top of the paper.
Publisher: The Royal Society
Date: 25-02-2009
Abstract: For multiple-brooded species, the number of reproductive events per year is a major determinant of an in idual's fitness. Where multiple brooding is facultative, its occurrence is likely to change with environmental conditions, and, as a consequence, the current rates of environmental change could have substantial impacts on breeding patterns. Here we examine temporal population-level trends in the proportion of female great tits ( Parus major ) producing two clutches per year (‘double brooding’) in four long-term study populations in The Netherlands, and show that the proportion of females that double brood has declined in all populations, with the strongest decline taking place in the last 30 years of the study. For one of the populations, for which we have data on caterpillar abundance, we show that the probability that a female produces a second clutch was related to the timing of her first clutch relative to the peak in caterpillar abundance, and that the probability of double brooding declined over the study period. We further show that the number of recruits from the second clutch decreased significantly over the period 1973–2004 in all populations. Our results indicate that adjustment to changing climatic conditions may involve shifts in life-history traits other than simply the timing of breeding.
Location: United Kingdom of Great Britain and Northern Ireland
No related grants have been discovered for Van Ngo.