1. Editorial : acidification and hypoxia in marginal seasXianghui Guo, Nina Bednaršek, Hongjie Wang, Richard Alan Feely, Laurent Arnaud, 2022, other scientific articles Abstract: Ocean acidification and hypoxia (dissolved oxygen <2 mg L−1 or <62 μmol L−1) are universal environmental concerns that can impact ecological and biogeochemical processes, including element cycling, carbon sequestration, community shifts, contributing to biodiversity reduction, and reducing marine ecosystem services (Riebesell et al., 2000; Feely et al., 2004, 2009; Andersson et al., 2005; Doney, 2006; Cohen and Holcomb, 2009; Doney et al., 2009, 2020; Kleypas and Yates, 2009; Ekstrom et al., 2015; Gattuso et al., 2015). While the stressors are global in their occurrence, local and regional impacts might be enhanced and even more accelerated, thus requiring even greater and faster consideration (Doney et al., 2020). Keywords: coastal ecosystems, ocean acidification, zakisljevanje morja, biological impacts, hypoxia, hydrobiology Published in DiRROS: 06.08.2024; Views: 87; Downloads: 38
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2. The hypoxic peri-arteriolar glioma stem cell niche, an integrated concept of five types of niches in human glioblastomaDiana A. Aderetti, Vashendriya V. V. Hira, Remco J. Molenaar, Cornelis J. F. van Noorden, 2018, review article Abstract: Glioblastoma is the most lethal primary brain tumor and poor survival of glioblastoma patients is attributed to the presence of glioma stem cells (GSCs). These therapy-resistant, quiescent and pluripotent cells reside in GSC niches, which are specific microenvironments that protect GSCs against radiotherapy and chemotherapy. We previously showed the existence of hypoxic peri-arteriolar GSC niches in glioblastoma tumor samples. However, other studies have described peri-vascular niches, peri-hypoxic niches, peri-immune niches and extracellular matrix niches of GSCs. The aim of this review was to critically evaluate the literature on these five different types of GSC niches. In the present review, we describe that the five niche types are not distinct from one another, but should be considered to be parts of one integral GSC niche model, the hypoxic peri-arteriolar GSC niche. Moreover, hypoxic peri-arteriolar GSC niches are structural and functional look-alikes of hematopoietic stem cell (HSC) niches in the bone marrow. GSCs are maintained in peri-arteriolar niches by the same receptor-ligand interactions as HSCs in bone marrow. Our concept should be rigidly tested in the near future and applied to develop therapies to expel and keep GSCs out of their protective niches to render them more vulnerable to standard therapies. Keywords: glioblastoma, glioma stem cells, niches, blood vessels, extracellular matrix, tumor microenvironment, hypoxia, therapy resistance, vasculature Published in DiRROS: 06.08.2024; Views: 63; Downloads: 60
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4. Extreme environments simplify reassembly of communities of arbuscular mycorrhizal fungiNataša Šibanc, Dave R. Clark, Thorunn Helgason, Alex J. Dumbrell, Irena Maček, 2024, original scientific article Abstract: The ecological impacts of long-term (press) disturbance on mechanisms regulating the relative abundance (i.e., commonness or rarity) and temporal dynamics of species within a community remain largely unknown. This is particularly true for the functionally important arbuscular mycorrhizal (AM) fungi; obligate plant-root endosymbionts that colonize more than two-thirds of terrestrial plant species. Here, we use high-resolution amplicon sequencing to examine how AM fungal communities in a specific extreme ecosystem—mofettes or natural CO2 springs caused by geological CO2 exhalations—are affected by long-term stress. We found that in mofettes, specific and temporally stable communities form as a subset of the local metacommunity. These communities are less diverse and dominated by adapted, “stress tolerant” taxa. Those taxa are rare in control locations and more benign environments worldwide, but show a stable temporal pattern in the extreme sites, consistently dominating the communities in grassland mofettes. This pattern of lower diversity and high dominance of specific taxa has been confirmed as relatively stable over several sampling years and is independently observed across multiple geographic locations (mofettes in different countries). This study implies that the response of soil microbial community composition to long-term stress is relatively predictable, which can also reflect the community response to other anthropogenic stressors (e.g., heavy metal pollution or land use change). Moreover, as AM fungi are functionally differentiated, with different taxa providing different benefits to host plants, changes in community structure in response to long-term environmental change have the potential to impact terrestrial plant communities and their productivity Keywords: arbuscular mycorrhiza, elevated CO2, long-term experiments, soil biodiversity, soil hypoxia, next-generation sequencing, NGS Published in DiRROS: 28.02.2024; Views: 403; Downloads: 206
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