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Identifying long-term stable refugia for relict plant species in East Asia
No full textToday East Asia harbors many "relict" plant species whose ranges were much larger during the Paleogene-Neogene and earlier. The ecological and climatic conditions suitable for these relict species have not been identified. Here, we map the abundance and distribution patterns of relict species, showing high abundance in the humid subtropical/warm-temperate forest regions. We further use Ecological Niche Modeling to show that these patterns align with maps of climate refugia, and we predict species' chances of persistence given the future climatic changes expected for East Asia. By 2070, potentially suitable areas with high richness of relict species will decrease, although the areas as a whole will probably expand. We identify areas in southwestern China and northern Vietnam as long-term climatically stable refugia likely to preserve ancient lineages, highlighting areas that could be prioritized for conservation of such species
Daytime driving decreases amphibian roadkill
No full textRoadkill has gradually become a common factor that has contributed to the decline of amphibians, and traffic volume is an important parameter that can be used to determine the impacts of roads. However, few researchers have studied the effects of either daily or nightly traffic volume on amphibian roadkill in China. Hence, as an essential step for implementing mitigation measures, we conducted 77 road surveys along 10 km of road in the Wanglang National Nature Reserve (NNR) to determine the temporal and spatial distribution patterns of amphibian road mortality. In total, 298 dead individuals (Bufo andrewsi and Rana chensinensis) were observed on the road from April to October in 2017 and during June and August in 2015 and 2016. B. andrewsi had the highest number of records (85.2%) and was more vulnerable to road mortality than R. chensinensis. Amphibian fatalities mainly occurred during the breeding season in April, but there was an additional concentration of B. andrewsi roadkill in June and July. There was a significantly positive correlation between amphibian road mortality and mean night-time traffic volume. Roadkill hotspots were non-randomly distributed throughout the study area and were mainly concentrated in the road sections near the breeding pools. Therefore, to effectively mitigate the effects of road mortality in the Wanglang NNR, measures should be implemented both during hot moments and at hotspots. First, based on roadkill hot moments, during the breeding season (in April) and in June and July, the Wanglang NNR should establish temporary traffic restraints at night. Second, based on roadkill hotspots, culverts should be established in areas near breeding pools adjacent to roads, and barrier walls should be installed to guide amphibians into the culverts
Nine new species of Hymenasplenium (Aspleniaceae) from Asia
No full textNine new species of Hymenasplenium (Aspleniaceae) from Asia are here described based on both morphology and our recent molecular phylogenetics of the genus. Of the nine new species, H. chingii, H. denticulatum, H. sinense, H. speluncicola, and H. wangpeishanii are from southern China, whereas H. distans, H. ngheanense, H. phamhoanghoi, and H. quangnamense are from Vietnam. These new species are morphologically similar to but distinguishable from those of the H. unilaterale s. l. group (H. apogamum, H. hondoense, and H. murakami-hatanakae). All except one new species were included in a recent phylogenetic analysis and were well supported as distinct lineages based on molecular data. All new species are illustrated and the information on their distributions, habitats, and major distinguishing characters is provided
Asplenium cyrtosorum (Aspleniaceae), a new fern from Yunnan, China
No full textA new species, Asplenium cyrtosorum, is described and illustrated from Pu'er, southwestern Yunnan, China It was observed to grow in humid and shady conditions in the tropical seasonal rainforest. The new species differs from the morphologically most similar species A. trapezoideum by its shape of rhizome, length of rhizome scales, structure of laminae, pinna pairs and rachis structure
H2O2-Responsive Nanoparticle Based on the Supramolecular Self-Assemble of Cyclodextrin
No full textDesigning stimuli responsive, controllable and biocompatible multifunctional nanoparticles is an important progress in the current quest for drug delivery systems. Herein, we devoted to developing a beta-cyclodextrin (beta-CD) based drug delivery nanoparticles (NPs) that release Bovine serum albumin ( BSA) via glucose-responsive gate. The design involves synthesis of sodium alginate with beta-CD modified ( Alg-beta-CD) and methoxypolyethylene glycol (mPEG-Fc) containing ferrocene (Fc) uncharged end-capping. When alpha-cyclodextrin (alpha-CD) was added with these two segments, the stable non-covalent supramolecular structure of Alg-beta-CD/mPEG-Fc/alpha-CD can be selfassembled into NPs in aqueous solution. BSA loaded Alg-beta-CD/mPEG-Fc/alpha-CD also has been prepared. Interestingly, these supramolecular Alg-beta-CD/mPEG-Fc/alpha-CD/BSA NPs showed uniform sphere structure and constant BSA loading content. Also, this new kind of NPs can disassemble in the present of hydrogen peroxide (H2O2). Since glucose oxidase ( GOD) can oxidize glucose and produce H2O2, so this kind of polymeric NPs can also have glucose responsive behavior in the GOD containing environment. Developed functional Alg-beta-CD/mPEG-Fc/alpha-CD might be a promising drug delivery strategy for diabetes or immunotherapy with more efficiency
Using sulfinamides as high oxidation state sulfur reagent for preparation of sulfenamides
No full textTraditional preparation of sulfenamides require the use of low oxidation state of sulfur reagent such as RSCI, (RS)(2) or RSH, which are toxic, odorous and difficult to deal with due to the harsh reaction conditions. Here high oxidation state of sulfur reagent aliphatic sulfinamide, were used for preparation of sulfenamide in one step efficiently. Different aromatic amines with all sorts of functional groups, especially amino groups and hydroxyl groups, were transformed to the corresponding sulfenamides in moderate yields, which was difficult to obtain with previous methods. (C) 2018 Elsevier Ltd. All rights reserved
ROS-Mediated 15-Hydroxyprostaglandin Dehydrogenase Degradation via Cysteine Oxidation Promotes NAD(+)-Mediated Epithelial-Mesenchymal Transition
No full textNicotinamide adenine dinucleotide (NAD) levels decrease with aging as a result of aging-associated CD38 upregulation. Here, we established a cell model with decreased cellular NAD levels by overexpressing CD38 or treating cells with FK866, an inhibitor of nicotinamide phosphoribosyltransferase. We revealed that decreased NAD triggered reactive oxygen species (ROS)-mediated degradation of 15-hydroxyprostaglandin dehydrogenase (15-PGDH), which drove cells to undergo epithelial-mesenchymal transition (EMT). Moreover, we showed that oxidation of the Cys44 residue to sulfonic acid in 15-PGDH led to its degradation via non-canonical ubiquitination-proteasome and autophagy pathways. Mutation of Cys44 to alanine abolished ROS-induced 15-PGDH degradation. We demonstrated that 15-PGDH silencing promoted EMT, whereas supplementation with NAD precursors increased NAD and 15-PGDH stability, and reversed the EMT process. Taken together, these results suggest that declining NAD levels contribute to age-dependent increases in cancer incidence, and repletion of NAD precursors is beneficial for increasing 15-PGDH expression
A Genome-Wide Association Study of Wheat Spike Related Traits in China
No full textRapid detection of allelic variation and identification of advantage haplotypes responsible for spike related traits play a crucial role in wheat yield improvement. The released genome sequence of hexaploid wheat (Chinese Spring) provides an extraordinary opportunity for rapid detection of natural variation and promotes breeding application. Here, selection signals detection and genome-wide association study (GWAS) were conducted for spike related traits. Based on the genotyping results by 90K SNP chip, 192 common wheat samples from southwest China were analyzed. One hundred and forty-six selective windows and one hundred and eighty-four significant SNPs (51 for spike length, 28 for kernels per spike, 39 for spikelet number, 30 for thousand kernel weight, and 36 for spike number per plant) were detected. Furthermore, tightly linkage and environmental stability window clusters and SNP clusters were also obtained. As a result, four SNP clusters associated with spike length were detected on chromosome 2A, 2B, 2D, and 6A. Two SNP clusters correlated to kernels per spike were detected on 2A and 2B. One pleiotropy SNP cluster correlated to spikelet number and kernels per spike was detected on 7B. According to the genome sequence, these SNP clusters and their overlapped/flanking QTLs which have been reported previously were integrated to a physical map. The candidate genes responsible for spike length, kernels per spike and spikelet number were predicted. Based on the genotypes of cultivars in south China, two advantage haplotypes associated with spike length and one advantage haplotype associated with kernels per spike/spikelet number were detected which have not been effectively transited into cultivars. According to these haplotypes, KASP markers were developed and diagnosed across landraces and cultivars which were selected from south and north China. Consequently, KASP assay, consistent with the GWAS results, provides reliable haplotypes for MAS in wheat yield improvement
Resurrection of the genus Leptomantis, with Description of a New genus to the family Rhacophoridae (Amphibia: Anura)
Full text linkGenus Rhacophorus Kuhl and Van Hasselt, 1 822 is one of the most diverse genera of the family Rhacophoridae, and its taxonomy of genus Rhacophorus faces major challenges because of rapidly described new species and complex interspecies relations. In this study, we investigate the generic taxonomy within the genus Rhacophorus based on 1 972 bp of mitochondrial genes (12S rRNA, tRNA-val and 16S rRNA), containing 102 sequences from 58 species. The results reveal three well-supported and highly diverged matrilines that correspond with morphological characteristics and geographic distribution. Accordingly, we consider these three lineages as distinct genera: Rhacophorus sensu stricto, resurrected genus Leptomantis Peters, 1867, and the genus Zhangixalus gen. nov