13 research outputs found
TRY plant trait database â enhanced coverage and open access
Plant traitsâthe morphological, anatomical, physiological, biochemical and phenological characteristics of plantsâdetermine how plants respond to environmental factors, affect other trophic levels, and influence ecosystem properties and their benefits and detriments to people. Plant trait data thus represent the basis for a vast area of research spanning from evolutionary biology, community and functional ecology, to biodiversity conservation, ecosystem and landscape management, restoration, biogeography and earth system modelling. Since its foundation in 2007, the TRY database of plant traits has grown continuously. It now provides unprecedented data coverage under an open access data policy and is the main plant trait database used by the research community worldwide. Increasingly, the TRY database also supports new frontiers of traitâbased plant research, including the identification of data gaps and the subsequent mobilization or measurement of new data. To support this development, in this article we evaluate the extent of the trait data compiled in TRY and analyse emerging patterns of data coverage and representativeness. Best species coverage is achieved for categorical traitsâalmost complete coverage for âplant growth formâ. However, most traits relevant for ecology and vegetation modelling are characterized by continuous intraspecific variation and traitâenvironmental relationships. These traits have to be measured on individual plants in their respective environment. Despite unprecedented data coverage, we observe a humbling lack of completeness and representativeness of these continuous traits in many aspects. We, therefore, conclude that reducing data gaps and biases in the TRY database remains a key challenge and requires a coordinated approach to data mobilization and trait measurements. This can only be achieved in collaboration with other initiatives
Direct effect of p,p'- DDT on mice liver
ABSTRACT Contact with the pesticide dichlorodiphenyltrichloroethane (p,p′-DDT) can be the cause of various harmful effects in humans, wildlife, and the environment. This pesticide is known to be persistent, lipophilic, resistant to degradation, and bioaccumulive in the environment and to be slowly released into bloodstream. Growing evidence shows that exposure to DDT is linked to type 2 diabetes mellitus. Individuals exposed to elevated levels of DDT and its metabolite have an increased prevalence of diabetes and insulin resistance. To evaluate these possible relationships, experiments were performed on eight-week-old female mice, divided into three groups (n = 10 per group): Group 1 received a vehicle-control intraperitoneal (i.p.) injection of sesame oil; Groups 2 and 3 received an i.p. dose of 50 and 100 ”g/g p,p′-DDT respectively, dissolved in sesame oil. All groups were treated once daily for four days. Real-time PCR analysis of several genes was undertaken. Additionally, biochemical parameters and histopathological changes were measured. NQO1, HMOX1, NR1I3 and NR3C1 were up-regulated in DDT-exposed animals compared to the vehicle control group, while only SREBP1 was down-regulated in the 100 ”g/g group. MTTP and FABP5, not previously reported for DDT exposure, but involved in regulation of fatty acid fluxes, could also function as biomarkers cross-talking between these signaling pathways. These results suggest that beyond epidemiological data, there is increasing molecular evidence that DDT may mimic different processes involved in diabetes and insulin resistance pathways
Neural tube closure depends on expression of Grainyhead-like 3 in multiple tissues.
Failure of neural tube closure leads to neural tube defects (NTDs), common congenital abnormalities in humans. Among the genes whose loss of function causes NTDs in mice, Grainyhead-like3 (Grhl3) is essential for spinal neural tube closure, with null mutants exhibiting fully penetrant spina bifida. During spinal neurulation Grhl3 is initially expressed in the surface (non-neural) ectoderm, subsequently in the neuroepithelial component of the neural folds and at the node-streak border, and finally in the hindgut endoderm. Here, we show that endoderm-specific knockout of Grhl3 causes late-arising spinal NTDs, preceded by increased ventral curvature of the caudal region which was shown previously to suppress closure of the spinal neural folds. This finding supports the hypothesis that diminished Grhl3 expression in the hindgut is the cause of spinal NTDs in the curly tail, carrying a hypomorphic Grhl3 allele. Complete loss of Grhl3 function produces a more severe phenotype in which closure fails earlier in neurulation, before the stage of onset of expression in the hindgut of wild-type embryos. This implicates additional tissues and NTD mechanisms in Grhl3 null embryos. Conditional knockout of Grhl3 in the neural plate and node-streak border has minimal effect on closure, suggesting that abnormal function of surface ectoderm, where Grhl3 transcripts are first detected, is primarily responsible for early failure of spinal neurulation in Grhl3 null embryos
Dibenzofuran-induced mitochondrial dysfunction: Interaction with ANT carrier
Exposure to environmental pollutants such as dibenzofurans and furans is linked to the pathophysiology
of several diseases. Dibenzofuran (DBF) is listed as a pollutant of concern due to its persistence in the
environment, bioaccumulation and toxicity to humans, being associated with the development of lung
diseases and cancers, due to its extremely toxic properties such as carcinogenic and teratogenic.
Mitochondria play a key role in cellular homeostasis and keeping a proper energy supply for eukaryotic
cells is essential in the fulfillment of the tissues energy-demand. Therefore, interference with mitochondrial
function leads to cell death and organ failure. In this work, the effects of DBF on isolated rat liver
mitochondria were analyzed.
DBF exposure caused a markedly increase in the lag phase that follows depolarization induced by ADP,
indicating an effect in the phosphorylative system. This was associated with a dose-dependent decrease
in ATPase activity. Moreover, DBF also increased the threshold to the induction of the mitochondrial permeability
transition (MPT) by calcium. Pretreatment of mitochondria with DBF also increased the concentration
of carboxyatractyloside (CAT) necessary to abolish ADP phosphorylation and to induce the MPT,
suggesting that DBF may interfere with mitochondria through an effect on the adenine nucleotide translocase
(ANT). By co-immunoprecipitating ANT and Cyclophilin D (CypD) following MPT induction, we
observed that in the presence of DBF, the ratio CypD/ANT was decreased. This demonstrates that DBF
interferes with the ANT and so prevents CypD binding to the ANT, causing decreased phosphorylative
capacity and inhibiting the MPT, which is also reflected by an increase in calcium retention capacity.
Clarifying the role of pollutants in some mechanisms of toxicity, such as unbalance of bioenergetics status
and mitochondrial function, may help to explain the progressive and chronic evolution of diseases
derived from exposure to environmental pollutants.This work was supported by Fundação para a CiĂȘncia e a Tecnologia,
Portugal (grant SFRH/BD/38372/2007 to FVD, grant SFRH/BD/
44674/2008 to APG, grant SFRH/BD/38467/2007 to JST and grant
SFRH/BD/44796/2008 to ATV)
A metabolic and mitochondrial angle on aging.
The increasingly aged human population (mainly in developed countries) represents a significant scientific achievement and privilege associated with medical, social, and economic progress. However, it also poses several challenges to national health and social care systems. The uncoupling of biological evolution with the vast and fast technical progress achieved by humanity has minimized the role of natural selection and rendered aging almost an undesirable physiological event that most people desire to delay as much as possible. All this has been challenging modern gerontology to focus on potential strategies to extend the lifespan, but primarily to mitigate the negative thoughts often associated with aging and aged individuals