The impact of global climate change on genetic diversity within populations and species

Genetic diversity provides the basic substrate for evolution, yet few studies assess the impacts of global climate change (GCC) on intraspecific genetic variation. In this review, we highlight the importance of incorporating neutral and non‐neutral genetic diversity when assessing the impacts of GCC, for example, in studies that aim to predict the future distribution and fate of a species or ecological community. Specifically, we address the following questions: Why study the effects of GCC on intraspecific genetic diversity? How does GCC affect genetic diversity? How is the effect of GCC on genetic diversity currently studied? Where is potential for future research? For each of these questions, we provide a general background and highlight case studies across the animal, plant and microbial kingdoms. We further discuss how cryptic diversity can affect GCC assessments, how genetic diversity can be integrated into studies that aim to predict species' responses on GCC and how conservation efforts related to GCC can incorporate and profit from inclusion of genetic diversity assessments. We argue that studying the fate of intraspecifc genetic diversity is an indispensable and logical venture if we are to fully understand the consequences of GCC on biodiversity on all levels.     

Effect of choice of baseline correction interval on localization of electrical heart activity]

The electric heart activity can be localised from body surface mapping data with computer algorithms. At higher heart rates the T and P waves merge. Thus, the offset can not be subtracted in the TP segment. We investigated 28 healthy volunteers with signal averaged 31-lead magnetocardiography. The offset of the baseline was determined in the TP-segment and in the PR-segment, respectively. The electrical heart activity was localised in the initial 30 ms of the QRS complex (Q), at the QRS maximum (R), and at the T wave maximum (T). The volume currents were considered by using a boundary element model with the compartments lungs and torso. The 3D positions of the dipoles, the dipole orientations, and the dipole strengths were calculated using the data preprocessed with two different offset correction intervals. The offsets of the TP and PR segments significantly differed one from another. The average deviations of the dipole localisation were within a few centimetres (Q: 20 +/- 31 mm, R: 6 +/- 13 mm, T: 14 +/- 30 mm). However, in a small number of subjects (Q: n = 5, R: n = 2, T: n = 5) we observed a deviation of more than 30 mm. These deviations were not linearly correlated to the differences in the baseline offsets. High resolution recordings continuously detect heart activity in the PR segment. The correction of the baseline in the PR segment instead of the TP segment may introduce artefacts in the source localisation and therefore should be avoided.     

Invasion of Eragrostis albensis in Central Europe: distribution patterns,taxonomy and phylogenetic insight into the Eragrostis pilosa complex

The Eragrostis pilosa complex (Poaceae) comprises five widely distributed and regionally invasive species—E. albensis, E. amurensis, E. imberbis, E. multicaulis, and E. pilosa, distinguished by tiny and variable morphological characters and with so far unknown phylogenetic relationships. Recently, some doubts have been raised about the status of an invasive glandular morphotype occurring in Central Europe assigned either to E. amurensis or to E. albensis. Here, we addressed this issue by analysing morphology, internal transcribed spacers of nuclear ribosomal DNA, and five inter-simple sequence repeat markers. The genetic evidence supported closer relationship of this glandular morphotype to eglandular E. albensis, widely established in Central Europe, than to glandular E. amurensis described from Asia. We propose to adopt a new taxonomic treatment that E. albensis includes both eglandular and glandular individuals, and to classify the glandular ones as E. albensis var. scholziana M. Nobis & A. Wróbel var. nova. Currently this new taxon is known from a dozen of localities in Central Europe and is invasive in the lower section of the Oder River valley, whereas Eragrostis albensis var. albensis has already spread widely across Europe in riparian phytocenoses and anthropogenic habitats. Since probably the first registered records in 1940s, it has been observed in European part of Russia, Belarus, Ukraine, Poland, Slovakia, Czech Republic, Germany, Austria, the Netherlands, and its further invasion is likely to proceed. We provided distribution maps concerning spread dynamics of E. albensis in Europe from 1947 to 2020. In total, the species has been observed on over 1300 localities so far, most of which were found after 2000.

     

Vegetation of rock crevices of the montane and colline zones in the Pamir-Alai and Tian Shan Mts in Tajikistan (Middle Asia)

The paper presents the results of phytosociological research conducted on the vegetation of rock habitats in the montane and colline zones of the Pamir-Alai Mountains (Tajikistan). During field surveys done in 2010–2013, 122 phytosociological relevés were sampled. Plant species were recorded according to the Braun-Blanquet cover-abundance scale. The vegetation studies were carried out generally in the western Pamir-Alai and south-western Tian Shan Mts, especially in the Zeravshan, Hissar, Hazratishoh, Darvaz, Rushan, Turkestan, Kuramin and Vanch ranges. A synopsis of the rock communities of the montane and colline zones in Tajikistan is proposed. The collected material presents most of the variability among the plant communities of rock crevices and fissures on calcareous as well as acidic substrates in the montane and colline zones in Tajikistan. As a result of field research and numerical analyses, eight associations have been distinguished: Scutellarietum hissaricae, Scutellarietumschugnanicae, Scutellarietum zaprjagaevii, Scutellarietum baldshuanicae, Tylospermetumlignosae, Dionysietum involucratae A. Nowak, M. Nobis, S. Nowak & A. Nobis, 2014, Nanorrhinetum ramosissimi, Campanuletum albertii and the community of Scutellaria adenostegia within new alliance – Caricion koshevnikovii. The main factors determining the species composition of classified associations seem to be the geography of the distribution range, elevation above sea level, rock type and exposition.     

Transgenic pigs designed to express human α-galactosidase to avoid humoral xenograft rejection

The use of animals as a source of organs and tissues for xenotransplantation can overcome the growing shortage of human organ donors. However, the presence of xenoreactive antibodies in humans directed against swine Gal antigen present on the surface of xenograft donor cells leads to the complement activation and immediate xenograft rejection as a consequence of hyperacute reaction. To prevent hyperacute rejection, it is possible to change the swine genome by a human gene modifying the set of donor’s cell surface proteins. The gene construct pGal-GFPBsd containing the human gene encoding α-galactosidase enzyme under the promoter of EF-1α elongation factor ensuring systemic expression was introduced by microinjection into a male pronucleus of the fertilised porcine oocyte. As a result, the founder male pig was obtained with the transgene mapping to chromosome 11p12. The polymerase chain reaction (PCR) analysis revealed and the Southern analysis confirmed transgene integration estimating the approximate number of transgene copies as 16. Flow cytometry analysis revealed a reduction in the level of epitope Gal on the cell surface of cells isolated from F0 and F1 transgenic animals. The complement-mediated cytotoxicity assay showed increased viability of the transgenic cells in comparison with the wild-type, which confirmed the protective influence of α-galactosidase expression.     

No cumulative effect of 10 years of elevated [CO2] on perennial plant biomass components in the Mojave Desert

Elevated atmospheric CO₂ concentrations ([CO₂]) generally increase primary production of terrestrial ecosystems. Production responses to elevated [CO₂] may be particularly large in deserts, but information on their long‐term response is unknown. We evaluated the cumulative effects of elevated [CO₂] on primary production at the Nevada Desert FACE (free‐air carbon dioxide enrichment) Facility. Aboveground and belowground perennial plant biomass was harvested in an intact Mojave Desert ecosystem at the end of a 10‐year elevated [CO₂] experiment. We measured community standing biomass, biomass allocation, canopy cover, leaf area index (LAI), carbon and nitrogen content, and isotopic composition of plant tissues for five to eight dominant species. We provide the first long‐term results of elevated [CO₂] on biomass components of a desert ecosystem and offer information on understudied Mojave Desert species. In contrast to initial expectations, 10 years of elevated [CO₂] had no significant effect on standing biomass, biomass allocation, canopy cover, and C : N ratios of above‐ and belowground components. However, elevated [CO₂] increased short‐term responses, including leaf water‐use efficiency (WUE) as measured by carbon isotope discrimination and increased plot‐level LAI. Standing biomass, biomass allocation, canopy cover, and C : N ratios of above‐ and belowground pools significantly differed among dominant species, but responses to elevated [CO₂] did not vary among species, photosynthetic pathway (C₃ vs. C₄), or growth form (drought‐deciduous shrub vs. evergreen shrub vs. grass). Thus, even though previous and current results occasionally show increased leaf‐level photosynthetic rates, WUE, LAI, and plant growth under elevated [CO₂] during the 10‐year experiment, most responses were in wet years and did not lead to sustained increases in community biomass. We presume that the lack of sustained biomass responses to elevated [CO₂] is explained by inter‐annual differences in water availability. Therefore, the high frequency of low precipitation years may constrain cumulative biomass responses to elevated [CO₂] in desert environments.     

Molecular basis of lateral force spectroscopy nano-diagnostics: computational unbinding of autism related chemokine MCP-1 from IgG antibody

Monocyte-chemoattractant protein-1 (MCP-1), also known as CCL2, is a potent chemoattractant of T cells and monocytes, involved in inflammatory and angio-proliferative brain and retinal diseases. Higher expression of MCP-1 is observed in metastatic tumors. Unusual levels of MCP-1 in the brain may be correlated with autism. Immunochemistry where atomic force microscope (AFM) tips functionalized with appropriate antibodies against MCP-1 are used could in principle support medical diagnostics. Useful signals from single molecule experiments may be generated if interaction forces are large enough. The chemokine-antibody unbinding force depends on a relative motion of the interacting fragments of the complex. In this paper the stability of the medically important MCP-1- immunoglobulin G antibody Fab fragment complex has been studied using steered molecular dynamics (SMD) computer simulations with the aim to model possible arrangements of nano-diagnostics experiments. Using SMD we confirm that molecular recognition in MCP1-IgG is based mainly on six pairs of residues: Glu39A - Arg98H, Lys56A - Asp52H, Asp65A - Arg32L, Asp68A - Arg32L, Thr32A - Glu55L, Gln61A - Tyr33H. The minimum external force required for mechanical dissociation of the complex depends on a direction of the force. The pulling of the MCP-1 antigen in the directions parallel to the antigen-antibody contact plane requires forces about 20 %–40 % lower than in the perpendicular one. Fortunately, these values are large enough that the fast lateral force spectroscopy may be used for effective nano-diagnostics purposes. We show that molecular modeling is a useful tool in planning AFM force spectroscopy experiments.