Biology subjects

Stark, G.

Publications and source records attributed to Stark, G..

5 recordsLinked to original sources

bioRxiv2026

The Hidden Costs of Climate Change Tracking: Climate Velocity, Movement Energetics, and Connectivity in European Protected Areas

Rapid climate change is reducing the capacity of protected areas (PAs) to conserve biodiversity, but exposure metrics alone do not show whether species can reach areas where suitable climates persist. We developed a climate-informed connectivity framework integrating climate velocity, PA climatic residence time, PA size, and functional connectivity based on energetics-informed resistance surfaces from species distribution models. Using high-resolution climate projections and omnidirectional connectivity modelling across Europe, we show that climate-tracking opportunities are more limited and spatially uneven than structural connectivity alone suggests. Small, climate-exposed PAs are especially vulnerable because they provide little internal climatic buffering and are often embedded in landscapes with low movement feasibility, whereas larger and more climatically stable PAs are more often situated in landscapes that can support redistribution. These findings provide a spatially explicit basis for restoration and conservation planning to maintain the functionality of PA networks under future climate change. TeaserMany European protected areas are too isolated, climate-exposed, and energy-constrained to support climate-tracking connectivity.

ecology↗

bioRxiv2025

Dissociating the Effects of Light at Night from Circadian Misalignment in a Neurodevelopmental Disorder Mouse Model Using Ultradian Light-Dark Cycles.

Individuals with neurodevelopmental disorders (NDDs) often experience sleep disturbances and are frequently exposed to light during nighttime hours. Our previous studies using the Cntnap2 knockout (KO) mouse model of NDDs demonstrated that nighttime light exposure increases behaviors such as excessive grooming, reduces social interactions, and disrupts daily locomotor rhythms. To further evaluate the effects of nighttime light exposure, we exposed wild-type (WT) and Cntnap2 KO mice to an ultradian lighting cycle (T7), which alternates 3.5 hours of light and 3.5 hours of darkness. Circadian rhythms in activity, corticosterone levels, and clock gene expression are maintained under T7 lighting despite the presence of light during the usual night phase, whilst animals display increased depressive-like behaviors and reduce performance on the novel object recognition test. Based on these observations, we hypothesized that T7 lighting would mimic the impact of nighttime light exposure seen in standard light-dark cycles with dim light at night (DLaN). However, in this study, adult WT and Cntnap2 KO mice held under the T7 cycle did not show the increased grooming behavior or reduced social interaction observed in Cntnap2 KO mice exposed to DLaN. Regarding locomotor activity rhythms, the T7 cycle lengthened the circadian period and weakened the rhythm amplitude but did not abolish rhythmicity in either genotype. Finally, opposite to DLaN, neither the T7 cycle nor constant darkness (DD) elicited an increase in cFos expression in the basolateral amygdala in WT and KO mice. These results demonstrate that the adverse behavioral and neurobiological effects of nighttime light exposure in a model of a neurodevelopmental disorder depend on circadian disruption rather than light exposure alone, highlighting the importance of circadian stability as a protective factor in NDDS.

neuroscience↗

bioRxiv2025

TOWARDS CLIMATE-SMART REWILDING: AN INTEGRATED FRAMEWORK FOR BIODIVERSITY, CLIMATE CHANGE, AND SOCIETY

The UN Decade on Ecosystem Restoration and the Kunming-Montreal Global Biodiversity Framework aim to restore 30% of degraded ecosystems. Both the IPCC and IPBES highlight the crucial role of ecosystem restoration in addressing the interconnected crises of climate change and biodiversity loss. One key restoration strategy is rewilding, which enhances ecosystem complexity with minimal human intervention. While traditional rewilding strategies often focus on benefits for biodiversity, we propose a climate-smart rewilding framework as a new approach designed to deliver climate benefits alongside biodiversity restoration. This framework seeks to integrate biodiversity, climate change adaptation and mitigation, as well as socio-economic benefits and trade-offs. We illustrate how this framework can be utilized to identify areas across Europe where rewilding could increase carbon sequestration, enhance species abilities to adapt to the velocity of climate change, and maximize wildlife-watching benefits while minimizing the costs associated with livestock-wildlife conflict. Finally, we acknowledge some limitations of climate-smart rewilding, but we argue that its adaptability and low cost render it a promising solution to the challenges facing Europe and beyond.

ecology↗

bioRxiv2023

Sex Differences in Sleep Phenotypes in the BACHD Mouse Model of Huntington's Disease

Sleep and circadian rhythm disturbances are common features of Huntingtons disease (HD). HD is an autosomal dominant neurodegenerative disorder that affects men and women in equal numbers, but some epidemiological studies as well as preclinical work indicate there may be sex differences in disease progression. Since sex differences in HD could provide important insights to understand cellular and molecular mechanism(s), we used the bacterial artificial chromosome transgenic mouse model of HD (BACHD) to examine whether sex differences in sleep/wake cycles are detectable in an animal model of the disease. Electroencephalography/electromyography (EEG/EMG) was used to measure sleep/wake states and polysomnographic patterns in young adult (12 week-old) male and female wild-type and BACHD mice. Our findings show that male, but not female, BACHD mice exhibited increased variation in phases of the rhythms as compared to age and sex matched wild-types. For both Rapid-eye movement (REM) and Non-rapid eye movement (NREM) sleep, genotypic and sex differences were detected. In particular, the BACHD males spent less time in NREM and exhibited a more fragmented sleep than the other groups. Both male and female BACHD mice exhibited significant changes in delta but not in gamma power compared to wild-type mice. Finally, in response to a 6-hrs sleep deprivation, both genotypes and sexes displayed predicted homeostatic responses to sleep loss. These findings suggest that females are relatively protected early in disease progression in this HD model. Significance StatementSleep and circadian rhythm disturbances are common features of Huntingtons disease (HD). Using an animal model of HD and EEG measures of sleep, we found that the males were more vulnerable to sleep/wake architecture alterations and sleep fragmentation. Homeostatic recovery from sleep loss did not appear to be altered at this stage of the disease. These findings raise the possibility that sex-specific factors play a role in the HD symptom progression and that hormone-based treatments may have therapeutic utility.

neuroscience↗

bioRxiv2021

Fast and efficient CRISPR-mediated genome editing in Aureobasidium pullulans using Cas9 ribonucleoproteins

Aureobasidium pullulans is a ubiquitous, polyextremotolerant, "yeast-like" ascomycete used for the industrial production of pullulan and other products and as biocontrol agent in the agriculture. Its application potential and its wide-spread occurrence make A. pullulans an interesting study object. The availability of a fast and efficient genome editing method is an obvious advantage for future basic and applied research on A. pullulans. In this study, we describe the development of a CRISPR/Cas9-based genome editing method using ribonucleoproteins (RNPs). We demonstrate that this method can be used for single and multiplex genome editing using only RNPs by targeting ura3 (encoding for orotidine-5'-phosphate decarboxylase), praics (encoding for phosphoribosyl aminoimidazole-succinocarboxamide synthase) and asl (encoding for arginine succinate lyase). We demonstrate the applicability of Trichoderma reesei pyr4 and Aspergillus fumigatus pyrG to complement the ura3 deficiency. Further, we show that the usage of RNPs can boost the homologous recombination rate up to nearly 100%, even when using only 20bp long homologous flanks. Therefore, the repair cassettes can be constructed by a single PCR, abolishing the need for laborious and time-consuming cloning. The here presented method allows fast and efficient genome editing for gene deletions, modifications, and insertions in A. pullulans.

bioengineering↗