Identifying Mozambique's most critical areas for plant conservation: An evaluation of protected areas and Important Plant Areas

Successful protected area networks must represent biodiversity across taxonomic groups. However, too often plant species are overlooked in conservation planning, and the resulting protected areas may, as a result, fail to encompass the most important sites for plant diversity. The Mozambique Tropical Important Plant Areas project sought to promote the conservation of Mozambique's flora through the identification of Important Plant Areas (IPAs). Here, we use the Weighted Endemism including Global Endangerment (WEGE) index to identify the richest areas for rare and endemic plants in Mozambique and subsequently evaluate how well represented these hotspots are within the current protected area and IPA networks. We also examine the congruence between IPA and protected areas to identify opportunities for strengthening the conservation of plants in Mozambique. We found that high WEGE scores, representing areas rich in endemic/near-endemic and threatened species, predict the presence of IPAs in Mozambique, but do not predict the presence of protected areas. We also find that there is limited overlap between IPAs and protected areas in Mozambique. We demonstrate how IPAs could be an important tool for ensuring priority sites for plant diversity are included within protected area network expansions, particularly following the adoption of the “30 by 30” target agreed within the post-2020 Convention on Biological Diversity framework, with great potential for this method to be replicated elsewhere in the global tropics.     

Construction and characterization of a YAC library with a lowfrequency of chimeric clones from flow-sorted human chromosome 9

Human chromosome 9 DNA, flow-sorted from somaticcell hybrid PK-87-9, has been used to construct two complete digest YAC libraries. The combined representation of chromosome 9 in these libraries, estimated by hybridization of chromosome 9-specific sequences to YAC colony grids, is 95%. The frequency of chimeric clones, analyzed by fluorescence in situ hybridization of chromosome 9 YACs to human metaphase chromosomes, was estimated to be 4%. These libraries provide a resource for physical mapping and for moving from genetic markers to disease loci on chromosome 9.     

Diversity and evolution of leaflet anatomical characters in the Pterocarpus clade (Fabaceae: Papilionoideae)

Journal of Plant Research - The Pterocarpus clade includes 23 genera previously attributed to different Fabaceae tribes. The recent rearrangements of many genera in the clade do not recognize...     

Human pluripotent stem cell-derived extracellular vesicles: From now to the future

Extracellular vesicles (EVs) are nanometric particles that enclose cell-derived bioactive molecules in a lipid bilayer and serve as intercellular communication tools. Accordingly, in various biological contexts, EVs are reported to engage in immune modulation, senescence, and cell proliferation and differentiation. Therefore, EVs could be key elements for potential off-the-shelf cell-free therapy. Little has been studied regarding EVs derived from human pluripotent stem cells (hPSC-EVs), even though hPSCs offer good opportunities for induction of tissue regeneration and unlimited proliferative ability. In this review article, we provide an overview of studies using hPSC-EVs, focusing on identifying the conditions in which the cells are cultivated for the isolation of EVs, how they are characterized, and applications already demonstrated. The topics reported in this article highlight the incipient status of the studies in the field and the significance of hPSC-EVs’ prospective applications as PSC-derived cell-free therapy products.     

Bioguided Fractionation and Isolation of an Antiplasmodial Saponin from the Roots of Nauclea xanthoxylon (A.Chev.) Aubrév. (Rubiaceae)

The root extract of Nauclea xanthoxylon (A.Chev.) Aubrév. displayed significant 50 % inhibition concentration (IC₅₀s) of 0.57 and 1.26 μg/mL against chloroquine resistant and sensitive Plasmodium falciparum (Pf) Dd2 and 3D7 strains, respectively. Bio-guided fractionation led to an ethyl acetate fraction with IC₅₀s of 2.68 and 1.85 μg/mL and subsequently, to the new quinovic acid saponin named xanthoxyloside ( 1 ) with IC₅₀s of 0.33 and 1.30 μM, respectively against the tested strains. Further compounds obtained from ethyl acetate and hexane fractions were the known clethric acid ( 2 ), ursolic acid ( 3 ), quafrinoic acid ( 4 ), quinovic acid ( 5 ), quinovic acid 3-O-β-D-fucopyranoside ( 6 ), oleanolic acid ( 7 ), oleanolic acid 3-acetate ( 8 ), friedelin ( 9 ), β-sitosterol ( 10a ), stigmasterol ( 10b ) and stigmasterol 3-O-β-D-glucopyranoside ( 11 ). Their structures were characterised with the aid of comprehensive spectroscopic methods (1 and 2D NMR, Mass). Bio-assays were performed using nucleic acid gel stain (SYBR green I)-based fluorescence assay with chloroquine as reference. Extracts and compounds exhibited good selectivity indices (SIs) of >10. Significant antiplasmodial activities measured for the crude extract, the ethyl acetate fraction and xanthoxyloside ( 1 ) from that fraction can justify the use of the root of N. xanthoxylon in ethnomedicine to treat malaria.     

Flow cytometric detection of mitotic cells using the bromodeoxyuridine/DNA technique in combination with 90 degrees and forward scatter measurements

Mitotic cells could be well discriminated from the cells in the G1-, S- and G2-phases of the cell cycle using pulse labeling of S-phase cells with bromodeoxy-uridine (BrdUrd) and staining of the cells for incorporated BrdUrd and total DNA content. Unlabeled G2- and M-phase cells could be measured as two separate peaks according to propidium iodide fluorescence. M-phase cells showed lower propidium iodide fluorescence emission compared to G2-phase cells. The fluorescence difference of M- and G2-phase cells was caused by the different thermal denaturation of their DNA. Best separation of M- and G2-phase cells was obtained after 30-50 min heat treatment at 95 degrees C. Mitotic index could be measured if no unlabeled S-phase cells were present in the cell culture. With additional measurements of 90 degree scatter and/or forward scatter signals, mitotic cells could be clearly discriminated from both unlabeled G2- and S-phase cells. The correct discrimination (about 99%) of mitotic cells from interphase cells was verified by visual analysis of the nuclear morphology after selective sorting. Unlabeled and labeled mitotic cells could be observed as pulse-labeled cells progressed through the cell cycle. We conclude that this modified BrdUrd/DNA technique using prolonged thermal denaturation and the simultaneous measurement of scatter signals may offer additional information especially in the presence of BrdUrd-unlabeled S-phase cells.     

Landscape-scale patterns of biological invasions in shoreline plant communities

Little is known about the patterns and dynamics of exotic species invasions at landscape to regional spatial scales. We quantified the presence (identity, abundance, and richness) and characteristics of native and exotic species in estuarine strandline plant communities at 24 sites in Narragansett Bay, Rhode Island, USA. Our results do not support several fundamental predictions of invasion biology. Established exotics (79 of 147 recorded plant species) were nearly indistinguishable from the native plant species (i.e. in terms of growth form, taxonomic grouping, and patterns of spatial distribution and abundance) and essentially represent a random sub-set of the current regional species pool. The cover and richness of exotic species varied substantially among quadrats and sites but were not strongly related to any site-level physical characteristics thought to affect invasibility (i.e. the physical disturbance regime, legal status, neighboring habitat type, and substrate characteristics). Native and exotic cover or richness were not negatively related within most sites. Across sites, native and exotic richness were positively correlated and exotic cover was unrelated to native richness. The colonization and spread of exotics does not appear to have been substantially reduced at sites with high native diversity. Furthermore, despite the fact that the Rhode Island strandline system is one of the most highly-invaded natural plant communities described to date, exotic species, both individually and as a group, currently appear to pose little threat to native plant diversity. Our findings are concordant with most recent, large-scale investigations that do not support the theoretical foundation of invasion biology and generally contradict small-scale experimental work.     

Quantitative histochemical assay for superoxide dismutase in rat brain.

Superoxide anions are highly reactive radicals overproduced in many pathological situations such as inflammation and ischemia. One of the major factors in the protection from superoxide anions is the enzyme superoxide dismutase (SOD), which catalyzes the dismutation of superoxide to hydrogen peroxide. This study presents a quantitative histochemical method to estimate SOD activity in rat brain tissue sections. This method is based on the cerium capture method and 3,3'-diaminobenzidine amplification of transition cerium compounds. Substrate for SOD was provided by reduction of oxygen during the autoxidation of riboflavin in the presence of UV light. This histochemical method reveals the overall activity of the three different forms of SOD described in mammalian tissues: cytosolic copper-zinc SOD, mitochondrial manganese SOD, and the high molecular weight extracellular SOD. Eventually, this method can be used to quantify SOD activity in tissue sections by image analysis.