Higher temperature variability in deforested mountain regions impacts the competitive advantage of nocturnal species.

Deforestation is a major contributor to biodiversity loss, yet the impact of forest loss on daily microclimate variability and its implications for species with different daily activity patterns remain poorly understood. Using a recently developed microclimate model, we investigated the effects of deforestation on the daily temperature range (DTR) in low-elevation tropical regions and high-elevation temperate regions. Our results show that deforestation substantially increases DTR in these areas, suggesting a potential impact on species interactions. To test this hypothesis, we studied the competitive interactions between nocturnal burying beetles and all-day-active blowfly maggots in forested and deforested habitats in Taiwan. We show that deforestation leads to increased DTR at higher elevations, which enhances the competitiveness of blowfly maggots during the day and leads to a higher failure rate of carcass burial by the beetles at night. Thus, deforestation-induced temperature variability not only modulates exploitative competition between species with different daily activity patterns, but also likely exacerbates the negative impacts of climate change on nocturnal organisms. In order to limit potential adverse effects on species interactions and their ecological functions, our study highlights the need to protect forests, especially in areas where deforestation can greatly alter temperature variability.

Glutamine synthetase licenses APC/C-mediated mitotic progression to drive cell growth.

Tumors can reprogram the functions of metabolic enzymes to fuel malignant growth; however, beyond their conventional functions, key metabolic enzymes have not been found to directly govern cell mitosis. Here, we report that glutamine synthetase (GS) promotes cell proliferation by licensing mitotic progression independently of its metabolic function. GS depletion, but not impairment of its enzymatic activity, results in mitotic arrest and multinucleation across multiple lung and liver cancer cell lines, patient-derived organoids and xenografted tumors. Mechanistically, GS directly interacts with the nuclear pore protein NUP88 to prevent its binding to CDC20. Such interaction licenses activation of the CDC20-mediated anaphase-promoting complex or cyclosome to ensure proper metaphase-to-anaphase transition. In addition, GS is overexpressed in human non-small cell lung cancer and its depletion reduces tumor growth in mice and increases the efficacy of microtubule-targeted chemotherapy. Our findings highlight a moonlighting function of GS in governing mitosis and illustrate how an essential metabolic enzyme promotes cell proliferation and tumor development, beyond its main metabolic function.

Author Correction: Locally-adapted reproductive photoperiodism determines population vulnerability to climate change in burying beetles.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

Locally-adapted reproductive photoperiodism determines population vulnerability to climate change in burying beetles.

Understanding how phenotypic traits vary among populations inhabiting different environments is critical for predicting a species' vulnerability to climate change. Yet, little is known about the key functional traits that determine the distribution of populations and the main mechanisms-phenotypic plasticity vs. local adaptation-underlying intraspecific functional trait variation. Using the Asian burying beetle Nicrophorus nepalensis, we demonstrate that mountain ranges differing in elevation and latitude offer unique thermal environments in which two functional traits-thermal tolerance and reproductive photoperiodism-interact to shape breeding phenology. We show that populations on different mountain ranges maintain similar thermal tolerances, but differ in reproductive photoperiodism. Through common garden and reciprocal transplant experiments, we confirm that reproductive photoperiodism is locally adapted and not phenotypically plastic. Accordingly, year-round breeding populations on mountains of intermediate elevation are likely to be most susceptible to future warming because maladaptation occurs when beetles try to breed at warmer temperatures.

In vitro modulation of mercury-induced rat liver mitochondria dysfunction.

Mercury (Hg) is a toxic environmental pollutant that exerts its cytotoxic effects as cations by targeting mitochondria. In our work, we determined different mitochondrial toxicity factors using specific substrates and inhibitors following the addition of Hg2+ to the mitochondria isolated from Wistar rat liver in vitro. We found that Hg2+ induced marked changes in the mitochondrial ultrastructure accompanied by mitochondrial swelling, mitochondrial membrane potential collapse, mitochondrial membrane fluidity increase and Cytochrome c release. Additionally, the effects of Hg2+ on heat production of mitochondria were investigated using microcalorimetry; simultaneously, the effects on mitochondrial respiration were determined by Clark oxygen-electric methods. Microcalorimetry could provide detailed kinetic and thermodynamic information which demonstrated that Hg2+ had some biotoxicity effect on mitochondria. The inhibition of energy metabolic activities suggested that high concentrations of Hg2+ could induce mitochondrial ATP depletion under MPT and mitochondrial respiration inhibition. These results help us learn more about the toxicity of Hg2+ at the subcellular level.

Asymmetric synthesis of heteroaryl atropisomers via a gold-catalyzed cycloisomerization-amination cascade reaction.

The chiral gold(i) complex enables enantioselective cycloisomerization-amination of 2-(alkynyl)phenyl boronic acids and diazenes in high yields. A wide scope of substrates bearing various functional groups was tolerated to generate structurally different hydrazide derivatives as a new type of atropisomer.