We report here arsenic speciation in 1643 freshwater fish samples,representing 14 common fish species from 53 waterbodies in Alberta,Canada.Arsenic species were extracted from fish muscle tissue.Arsenic species in the...We report here arsenic speciation in 1643 freshwater fish samples,representing 14 common fish species from 53 waterbodies in Alberta,Canada.Arsenic species were extracted from fish muscle tissue.Arsenic species in the extracts were separated using anion-exchange high-performance liquid chromatography(HPLC)and quantified using inductively coupled plasma mass spectrometry(ICPMS).The total arsenic concentrations in fish ranged from 2.8 to 1200μg/kg(in wet weight of sample)(mean 71±101μg/kg),which are all below the 2000μg/kg(wet weight)maximum allowable total arsenic in fish,recommended by the Ontario Ministry of the Environment.In 99.7%,or 1638 of all 1643 freshwater fish samples analyzed,arsenobetaine(AsB)was detectable,with concentrations higher than the method detection limit of 0.25μg/kg(wet weight).Dimethylarsinic acid(DMA)was detectable(concentration>0.25μg/kg)in 92.1%,or 1514 of the 1643 freshwater fish samples.Inorganic arsenate(iAs^(Ⅴ))was detectable(>0.25μg/kg)in 1119 fish(i.e.,68.1% of 1643 samples).Monomethylarsonic acid(MMA)was detectable(>0.25μg/kg)in 418 fish(25.4%of 1643 samples).The concentrations of arsenic species in the 1643 fish samples varied by as much as three orders of magnitude,ranging from below the method detection limit of 0.25μg/kg to the maximum concentrations of 380μg/kg for AsB,150μg/kg for DMA,70μg/kg for iAs^(Ⅴ),and 51μg/kg for MMA.AsB made up 46.1%±26.2% of total arsenic species.Arsenic speciation patterns varied between lake whitefish,northern pike,and walleye,the three most common types of fish analyzed.The relative proportion of DMA in northern pike was larger than in lake whitefish and walleye,and conversely,the relative proportion of iAs^(Ⅴ) was lower in northern pike.Seven unknown arsenic species were detected,and their chromatographic retention time did not match with those of available arsenic standards.At least one unknown arsenic species was detected in 33.4%,or 549 of 1643 freshwater fish samples.The concentrations of unknown arsenic species were as high as 61μg/kg.Future research is necessary to identify unknown arsenic species and to determine contributing factors to the observed arsenic species patterns and concentrations.展开更多
Arsenic speciation in freshwater fish is crucial for providing meaningful consumption guidelines that allow the public to make informed decisions regarding its consumption.While marine fish have attractedmuch research...Arsenic speciation in freshwater fish is crucial for providing meaningful consumption guidelines that allow the public to make informed decisions regarding its consumption.While marine fish have attractedmuch research interest due to their higher arsenic content,research on freshwater fish is limited due to the challenges in quantifying and identifying arsenic species present at trace levels.We describe here a sensitivemethod and its application to the quantification of arsenic species in freshwater fish.Arsenic species from fish tissues were extracted using a methanol/water mixture(1:1 vol.ratio)and ultrasound sonication.Anion-exchange high-performance liquid chromatography(HPLC)enabled separation of arsenobetaine(AsB),inorganic arsenite(iAs^(Ⅲ)),dimethylarsinic acid(DMA),monomethylarsonic acid(MMA),inorganic arsenate(iAs^(Ⅴ)),and three new arsenic species.Inductively coupled plasma mass spectrometry(ICPMS)provided highly sensitive and specific detection of arsenic.A limit of detection of 0.25μg/kg(wet weight fish tissue)was achieved for the five target arsenic species:AsB,iAs^(Ⅲ),DMA,MMA,and iAs^(Ⅴ).A series of experimentswere conducted to ensure the accuracy and validity of the analytical method.The method was successfully applied to the determination of arsenic species in lakewhitefish,northern pike,and walleye,with AsB,DMA,and iAs^(Ⅴ) being frequently detected.Three new arsenic species were detected,but their chromatographic retention times did not match with those of any available arsenic standards.Future research is necessary to elucidate the identity of these new arsenic species detected in freshwater fish.展开更多
pH-dependent multiple equilibria in cobalt sulfate-gluconate baths were calculated using stability constants adopted from literature.Changes of the bath speciation were then discussed in terms of spectrophotometric ex...pH-dependent multiple equilibria in cobalt sulfate-gluconate baths were calculated using stability constants adopted from literature.Changes of the bath speciation were then discussed in terms of spectrophotometric experiments and buffering properties of the solutions(pH 3-10).Cyclic voltammetry indicated changes in electrochemical behavior of cobalt species caused by different ionic compositions of the electrolytes.Tafel slopes were calculated and discussed in relation to electroreduction of cobalt species.Chronoamperometric studies showed 3D instantaneous nucleation of cobalt followed by diffusion-controlled growth,but it was disturbed at higher pH due to the release of cation from gluconate complexes as a limiting step.Diffusion coefficients of cobalt species were found.Changes in the pH were also reflected by modifications of morphology(SEM),development of preferred orientation planes(XRD,texture coefficients)and current efficiency,but not the thickness of the coatings deposited at constant potential of-1.0 V(vs Ag/AgCl).Anodic stripping analysis showed changes in anodic responses originated from the existence of preferentially oriented planes in cobalt layers.展开更多
Major geoclimatic events trigger clade divergence,shaping diversification patterns.However,the influence of historical geoclimatic events on the diversification of subsurface biota remains poorly understood.This study...Major geoclimatic events trigger clade divergence,shaping diversification patterns.However,the influence of historical geoclimatic events on the diversification of subsurface biota remains poorly understood.This study investigates the phylogeny and evolutionary history of under-recognized hypogean fishes in the Nemacheilidae family(HFN)in southwestern China,using mitogenome and nuclear gene sequencing.Our phylogeny supports the current genus-level classification but reveals conflicts between mitochondrial and nuclear gene topologies,suggesting past hybridization events.The ancestor of the HFN originated in eastern China-Korean Peninsula-Japanese Islands,north of northwest China-Mongolian Plateau,the Qinghai-Xizang(Tibetan)Plateau-Hengduan Mountains during the late Eocene(~36 million years ago[Mya])and early Miocene(~16 Mya),and dispersed twice into the karst region of southwestern China.An ancient radiation event occurred from 22.44 Mya to 12.25 Mya.In situ diversification is the major speciation event,originating around 30 Mya and increasing sharply at~11 Ma,with 3 peaks at~7 Mya,~3 Mya,and 1 Mya,and 2 valleys at~5 Mya and~2 Mya.Ancestral state reconstruction suggests at least 4 independent origins for the colorless,eye-blind,and troglobitic species morphs,as opposed to 2 events for the caudal adipose keel,and that these traits have undergone multiple reversals.These results highlight the role of geological processes and climatic events in the evolution of hypogean fishes and provide insights for conservation efforts,particularly in specialized cave habitats.展开更多
Species boundaries are dynamic and constantly challenged by gene flow.Understanding the strategies different lineages adopt to maintain ecological and genetic distinctiveness requires employing an integrative species ...Species boundaries are dynamic and constantly challenged by gene flow.Understanding the strategies different lineages adopt to maintain ecological and genetic distinctiveness requires employing an integrative species concept that incorporates data from a variety of sources.In this study,we incorporated genetic,ecological,and environmental evidence to assess the extent of speciation or evolutionary divergence within a monophyletic yet dimorphic group(i.e.,clade Leucolirion consisting of six species)within the genus Lilium.This clade consists of two lineages that exhibit unexpectedly distinct perianth appearances:whitish trumpet(funnel form,encompassing four species)and orange recurved(reflex form,including two species),respectively,which are separated by completely different pollination syndromes.Transcriptome-based nuclear and plastome datasets indicate that these two lineages are isolated,with only weak ancient gene flow between them.Within each lineage,several taxa with incomplete isolation have diverged,as indicated by weak genetic structure,strong gene flow,and conflicts between nuclear and chloroplast phylogenies,especially in the trumpet lineage.Although these taxa are not entirely independent,our evidence indicates that they are diverging,with recent gene flow disappearing and multiple isolation strategies emerging,such as differences in flowering time and niche specialization.Taken together,our findings suggest that species divergence and maintenance in Lilium are driven by a combination of adaptive and non-adaptive processes,highlighting the complex interplay of historical climate changes,ecological adaptation,and gene flow in shaping biodiversity within this genus.展开更多
The occurrence of geogenic arsenic(As)in groundwater is a global public health concern.However,there remain large gaps in groundwater As data,making it difficult to identify non-compliant domestic wells,partly due to ...The occurrence of geogenic arsenic(As)in groundwater is a global public health concern.However,there remain large gaps in groundwater As data,making it difficult to identify non-compliant domestic wells,partly due to lack of low-cost methods capable of rapid As analysis.Therefore,the development of high through-put and reliable on-site determination methods for inorganic As is essential.Herein,a portable automated analyzer was developed for the determination of arsenite(As(Ⅲ)),arsenate(As(Ⅴ))and phosphate in As contaminated groundwater based on a previously adapted method for molybdenum blue spectrophotometry.After the optimization of the chemical reactions and flow manifold,the system demonstrated a high sample through-put(4.8/h for As(Ⅲ),As(Ⅴ)and phosphate analysis),allowing this system to screen 125 samples in 24 h.Other advantages include low operational costs(0.3 CNY per sample),appropriate sensitivity for contaminated groundwater(detection limits of 4.7μg/L,8.3μg/L and 5.4μg/L for As(Ⅲ),As(Ⅴ)and phosphate,respectively),good linearity(R^(2)>0.9996 at As concentrations up to 1600μg/L)and high precision(relative standard deviations of 3.5% and 2.8% for As(Ⅲ)and As(Ⅴ),respectively).The portable system was successfully used for As speciation analysis in 5 groundwater samples collected from multi-level wells at Yinchuan Plain,northwestern China,with total As concentrations ranging from 75.7 to 295.0μg/L,independently assessing As speciation,providing a promising novel method for the rapid on-site screening of As in tens of millions of domestic wells worldwide.展开更多
Algal copper uptake(i.e.,Cu bioavailability)in the euphotic zone plays a vital role in algal photosynthesis and respiration,affecting the primary productivity and the source and sink of atmospheric carbon.Algal Cu upt...Algal copper uptake(i.e.,Cu bioavailability)in the euphotic zone plays a vital role in algal photosynthesis and respiration,affecting the primary productivity and the source and sink of atmospheric carbon.Algal Cu uptake is controlled by natural dissolved organic Cu(DOCu)speciation(i.e.,complexed with the dissolved organic matter)that conventionally could be tested by model prediction or molecular-level characterizations in the lab,while DOCu uptake are hardly directly assessed.Thus,the new chemistrybiology insight into the mechanisms of the Cu uptake process in algae is urgent.The DOCu speciation transformation(organic DOCu to free Cu(II)ions),enzymatic reduction-induced valence change(reduction of free Cu(II)to Cu(I)ions),and algal Cu uptake at the algae-water interface are imitated.Herein,an intelligent system with DOCu colorimetric sensor is developed for real-time monitoring of newly generated Cu(I)ions.Deep learning with whole sample image-based characterization and powerful feature extraction capabilities facilitates colorimetric measurement.In this context,the Cu bioavailability with 7 kinds of organic ligands(e.g.,amino acids,organic acids,carbohydrates)can be predicted by the mimetic intelligent biosensor within 15.0min,i.e.,the DOCu uptake and speciation is successfully predicted and streamlined by the biomimetic approach.展开更多
Cadmium(Cd)and arsenic(As)co-contamination has threatened rice production and food safety.It is challenging to mitigate Cd and As contamination in rice simultaneously due to their opposite geochemical behaviors.Mg-loa...Cadmium(Cd)and arsenic(As)co-contamination has threatened rice production and food safety.It is challenging to mitigate Cd and As contamination in rice simultaneously due to their opposite geochemical behaviors.Mg-loaded biochar with outstanding adsorption capacity for As and Cd was used for the first time to remediate Cd/As contaminated paddy soils.In addition,the effect of zero-valent iron(ZVI)on grain As speciation accumulation in alkaline paddy soils was first investigated.The effect of rice straw biochar(SC),magnesiumloaded rice straw biochar(Mg/SC),and ZVI on concentrations of Cd and As speciation in soil porewater and their accumulation in rice tissueswas investigated in a pot experiment.Addition of SC,Mg/SC and ZVI to soil reduced Cd concentrations in rice grain by 46.1%,90.3%and 100%,and inorganic As(iAs)by 35.4%,33.1%and 29.1%,respectively,and reduced Cd concentrations in porewater by 74.3%,96.5%and 96.2%,respectively.Reductions of 51.6%and 87.7%in porewater iAs concentrationswere observed with Mg/SC and ZVI amendments,but notwith SC.Dimethylarsinic acid(DMA)concentrations in porewater and grain increased by a factor of 4.9 and 3.3,respectively,with ZVI amendment.The three amendments affected grain concentrations of iAs,DMA and Cd mainly by modulating their translocation within plant and the levels of As(Ⅲ),silicon,dissolved organic carbon,iron or Cd in porewater.All three amendments(SC,Mg/SC and ZVI)have the potential to simultaneously mitigate Cd and iAs accumulation in rice grain,although the pathways are different.展开更多
The utilization and speciation transformation of α-S8 and μ-S by the typical mesophilic acidophilic strain Acidithiobacillus ferrooxidans ATCC 23270 were investigated.A.ferrooxidans cells first acclimated to the ene...The utilization and speciation transformation of α-S8 and μ-S by the typical mesophilic acidophilic strain Acidithiobacillus ferrooxidans ATCC 23270 were investigated.A.ferrooxidans cells first acclimated to the energy source α-S8 or μ-S,respectively.The results of cell growth and sulfur oxidation behavior showed that the strain grown on α-S8 entered slowly（about 1 d later） into the exponential phase,while grew faster in the exponential phase and attained higher maximal cell density and lower p H value than that on μ-S.After bio-corrosion,both of the two sulfur samples were evidently eroded and modified by A.ferrooxidans cells.After growth of A.ferrooxidans,the surface composition of amorphous μ-S became 63.1% μ-S and 36.9% α-S8,and that of orthorhombic α-S8 became 68.3% α-S8 and 31.7% μ-S,while the surface compositions of α-S8 and μ-S in sterile experiment were not changed,indicating that these two elemental sulfur species can be interconverted by A.ferrooxidans.展开更多
[Objective]The aim was to analyze the primary speciation of 6 microelements in Glycyrrhiza uralensis Fisch. and provide theoretical basis for explaining pharmacodynamic principle of liquorice and discussing quality co...[Objective]The aim was to analyze the primary speciation of 6 microelements in Glycyrrhiza uralensis Fisch. and provide theoretical basis for explaining pharmacodynamic principle of liquorice and discussing quality control of liquorice planting. [Method]The 6 elements Cu,Zn,Ca,Fe,Mg and Mn in roots of G.uralensis were extracted based on traditional decoction method and were separated into water-soluble state and suspension state by micro porous filtering film. The elements in water-soluble state were detected by flame atomic adsorption spectrophotometry （FAAS）. [Result]The results showed that extractive rates of the elements were in the range of 1.71%-60.06%,and immerse-residue ratio in 0.018 3-1.682 0; the results also indicated that the immerse-residue ratio of Zn was biggest （1.68）,Zn played an important medical role and might be considered as the best characteristic element in G.uralensis; the recoveries of the elements were ranged from 95.72% to 103.15% and relative standard deviations （RSD） were less than 2.38%. [Conclusion]Because of its high accuracy,FAAS method is feasible for analyzing primary speciation of microelements in G.uralensis.展开更多
Selection against hybridization can cause mating traits to diverge between species in sympatry via reproductive character displacement （RCD）. Additionally, selection against interspecific fighting can cause aggressi...Selection against hybridization can cause mating traits to diverge between species in sympatry via reproductive character displacement （RCD）. Additionally, selection against interspecific fighting can cause aggressive traits to diverge between sympatric species via agonistic character displacement （ACD）. By directly affecting conspecific recognition traits, RCD and ACD between species can also incidentally cause divergence in mating and fighting traits among populations within a species [termed cascade RCD （CRCD） and cascade ACD]. Here, we demonstrate patterns consistent with male-driven RCD and ACD in 2 groups of darters （orangethroat darter clade Ceasia and rainbow darter Etheostoma caeruleum）. In both groups, males that occur in sympatry （between Ceasia and E. caeruleum） have higher levels of preference for mating and fighting with conspecifics over heterospecifics than do males from allopatry. This is consistent with RCD and ACD. We also found patterns consistent with CRCD and cascade ACD among species of Ceasia. Ceasia males that are sympatric to E. caeruleum （but allopatric to one another） also have heightened preferences for mat- ing and fighting with conspecific versus heterospecific Ceasia. In contrast, Ceasia males that are allopatric to E. caeruleum readily mate and fight with heterospecific Ceasia. We suggest that RCD and ACD between Ceasia and E. caeruleum has incidentally led to divergence in mating and fighting traits among Ceasia species. This study is unique in that male preferences evolve via both RCD （male preference for conspecific females） and ACD （male preference to fight conspecific males） which leads to subsequent divergence among allopatric lineages.展开更多
A growing number of genes responsible for reproductive incompatibilities between species （barrier loci） exhibit the signals of positive selection. However, the possibility that genes experiencing positive selection ...A growing number of genes responsible for reproductive incompatibilities between species （barrier loci） exhibit the signals of positive selection. However, the possibility that genes experiencing positive selection diverge early in speciation and commonly cause reproductive incompatibilities has not been systematically investigated on a genome-wide scale. Here, I outline a research program for studying the genetic basis of speciation in broadcast spawning marine invertebrates that uses a priori genome-wide information on a large, unbiased sample of genes tested for positive selection. A targeted sequence capture approach is proposed that scores single-nucleotide polymorphisms （SNPs） in widely separated species populations at an early stage of allopatric divergence. The targeted capture of both coding and non-coding sequences enables SNPs to be characterized at known locations across the genome and at genes with known selective or neutral histories. The neutral coding and non-coding SNPs provide robust background distributions for identifying Fsm-outliers within genes that can, in principle, identify specific mutations experiencing diversifying selection. If natural hybridization occurs between species, the neutral coding and noncoding SNPs can provide a neutral admixture model for genomic clines analyses aimed at finding genes exhibiting strong blocks to introgression. Strongylocentrotid sea urchins are used as a model system to outline the approach but it can be used for any group that has a complete reference genome available.展开更多
Groups of organisms-whether multiple species or populations of a single species-can differ in several non-exclusive ways. For example, groups may have diverged phenotypically, genetically, or in the evolutionary respo...Groups of organisms-whether multiple species or populations of a single species-can differ in several non-exclusive ways. For example, groups may have diverged phenotypically, genetically, or in the evolutionary responses available to them. We tested for the latter of these-response di- vergence-between 2 species of woodrats： Neotoma fuscipes and Neotoma macrotis. Based on random skewers analyses we found that, despite being well differentiated both phenotypically and genetically, N. fuscipes and N. macrotis appear to be diverging along a shared evolutionary trajec- tory （ro = 0.895, P= 0.114）. Because these species are currently in secondary contact, their phenotypic evolution being along a shared evolutionary axis has important implications. In particular, that their response to selection arising from interspecific interactions will be constrained along the same evolutionary trajectory may reduce the potential for reinforcing selection to maintain species boundaries.展开更多
基金supported by Alberta Health,Alberta Innovates,the Canada Research Chairs program,the Canadian Institutes of Health Research,and the Natural Sciences and Engineering Research Council of Canada.
文摘We report here arsenic speciation in 1643 freshwater fish samples,representing 14 common fish species from 53 waterbodies in Alberta,Canada.Arsenic species were extracted from fish muscle tissue.Arsenic species in the extracts were separated using anion-exchange high-performance liquid chromatography(HPLC)and quantified using inductively coupled plasma mass spectrometry(ICPMS).The total arsenic concentrations in fish ranged from 2.8 to 1200μg/kg(in wet weight of sample)(mean 71±101μg/kg),which are all below the 2000μg/kg(wet weight)maximum allowable total arsenic in fish,recommended by the Ontario Ministry of the Environment.In 99.7%,or 1638 of all 1643 freshwater fish samples analyzed,arsenobetaine(AsB)was detectable,with concentrations higher than the method detection limit of 0.25μg/kg(wet weight).Dimethylarsinic acid(DMA)was detectable(concentration>0.25μg/kg)in 92.1%,or 1514 of the 1643 freshwater fish samples.Inorganic arsenate(iAs^(Ⅴ))was detectable(>0.25μg/kg)in 1119 fish(i.e.,68.1% of 1643 samples).Monomethylarsonic acid(MMA)was detectable(>0.25μg/kg)in 418 fish(25.4%of 1643 samples).The concentrations of arsenic species in the 1643 fish samples varied by as much as three orders of magnitude,ranging from below the method detection limit of 0.25μg/kg to the maximum concentrations of 380μg/kg for AsB,150μg/kg for DMA,70μg/kg for iAs^(Ⅴ),and 51μg/kg for MMA.AsB made up 46.1%±26.2% of total arsenic species.Arsenic speciation patterns varied between lake whitefish,northern pike,and walleye,the three most common types of fish analyzed.The relative proportion of DMA in northern pike was larger than in lake whitefish and walleye,and conversely,the relative proportion of iAs^(Ⅴ) was lower in northern pike.Seven unknown arsenic species were detected,and their chromatographic retention time did not match with those of available arsenic standards.At least one unknown arsenic species was detected in 33.4%,or 549 of 1643 freshwater fish samples.The concentrations of unknown arsenic species were as high as 61μg/kg.Future research is necessary to identify unknown arsenic species and to determine contributing factors to the observed arsenic species patterns and concentrations.
基金supported by Alberta Health,Alberta Innovates,the Canada Research Chairs Program,the Canadian Institutes of Health Research,and the Natural Sciences and Engineering Research Council of Canada。
文摘Arsenic speciation in freshwater fish is crucial for providing meaningful consumption guidelines that allow the public to make informed decisions regarding its consumption.While marine fish have attractedmuch research interest due to their higher arsenic content,research on freshwater fish is limited due to the challenges in quantifying and identifying arsenic species present at trace levels.We describe here a sensitivemethod and its application to the quantification of arsenic species in freshwater fish.Arsenic species from fish tissues were extracted using a methanol/water mixture(1:1 vol.ratio)and ultrasound sonication.Anion-exchange high-performance liquid chromatography(HPLC)enabled separation of arsenobetaine(AsB),inorganic arsenite(iAs^(Ⅲ)),dimethylarsinic acid(DMA),monomethylarsonic acid(MMA),inorganic arsenate(iAs^(Ⅴ)),and three new arsenic species.Inductively coupled plasma mass spectrometry(ICPMS)provided highly sensitive and specific detection of arsenic.A limit of detection of 0.25μg/kg(wet weight fish tissue)was achieved for the five target arsenic species:AsB,iAs^(Ⅲ),DMA,MMA,and iAs^(Ⅴ).A series of experimentswere conducted to ensure the accuracy and validity of the analytical method.The method was successfully applied to the determination of arsenic species in lakewhitefish,northern pike,and walleye,with AsB,DMA,and iAs^(Ⅴ) being frequently detected.Three new arsenic species were detected,but their chromatographic retention times did not match with those of any available arsenic standards.Future research is necessary to elucidate the identity of these new arsenic species detected in freshwater fish.
文摘pH-dependent multiple equilibria in cobalt sulfate-gluconate baths were calculated using stability constants adopted from literature.Changes of the bath speciation were then discussed in terms of spectrophotometric experiments and buffering properties of the solutions(pH 3-10).Cyclic voltammetry indicated changes in electrochemical behavior of cobalt species caused by different ionic compositions of the electrolytes.Tafel slopes were calculated and discussed in relation to electroreduction of cobalt species.Chronoamperometric studies showed 3D instantaneous nucleation of cobalt followed by diffusion-controlled growth,but it was disturbed at higher pH due to the release of cation from gluconate complexes as a limiting step.Diffusion coefficients of cobalt species were found.Changes in the pH were also reflected by modifications of morphology(SEM),development of preferred orientation planes(XRD,texture coefficients)and current efficiency,but not the thickness of the coatings deposited at constant potential of-1.0 V(vs Ag/AgCl).Anodic stripping analysis showed changes in anodic responses originated from the existence of preferentially oriented planes in cobalt layers.
基金supported by the Diversity and Distribution Survey of Chiroptera species in China(2021FY100302)the Guizhou Province Top Discipline Construction Program Project(Qianjiao Keyan Fa[2019]125)the Guizhou Normal University Academic Emerging Talent Fund Project(Qianshi Xin Miao[2021]).
文摘Major geoclimatic events trigger clade divergence,shaping diversification patterns.However,the influence of historical geoclimatic events on the diversification of subsurface biota remains poorly understood.This study investigates the phylogeny and evolutionary history of under-recognized hypogean fishes in the Nemacheilidae family(HFN)in southwestern China,using mitogenome and nuclear gene sequencing.Our phylogeny supports the current genus-level classification but reveals conflicts between mitochondrial and nuclear gene topologies,suggesting past hybridization events.The ancestor of the HFN originated in eastern China-Korean Peninsula-Japanese Islands,north of northwest China-Mongolian Plateau,the Qinghai-Xizang(Tibetan)Plateau-Hengduan Mountains during the late Eocene(~36 million years ago[Mya])and early Miocene(~16 Mya),and dispersed twice into the karst region of southwestern China.An ancient radiation event occurred from 22.44 Mya to 12.25 Mya.In situ diversification is the major speciation event,originating around 30 Mya and increasing sharply at~11 Ma,with 3 peaks at~7 Mya,~3 Mya,and 1 Mya,and 2 valleys at~5 Mya and~2 Mya.Ancestral state reconstruction suggests at least 4 independent origins for the colorless,eye-blind,and troglobitic species morphs,as opposed to 2 events for the caudal adipose keel,and that these traits have undergone multiple reversals.These results highlight the role of geological processes and climatic events in the evolution of hypogean fishes and provide insights for conservation efforts,particularly in specialized cave habitats.
基金supported by the National Natural Science Foundation of China(NSFC Grant Nos.32171605,31770406)Natural Science Foundation of Sichuan Province(Grant No.2023NSFSC0141)to Y.D.Gao.
文摘Species boundaries are dynamic and constantly challenged by gene flow.Understanding the strategies different lineages adopt to maintain ecological and genetic distinctiveness requires employing an integrative species concept that incorporates data from a variety of sources.In this study,we incorporated genetic,ecological,and environmental evidence to assess the extent of speciation or evolutionary divergence within a monophyletic yet dimorphic group(i.e.,clade Leucolirion consisting of six species)within the genus Lilium.This clade consists of two lineages that exhibit unexpectedly distinct perianth appearances:whitish trumpet(funnel form,encompassing four species)and orange recurved(reflex form,including two species),respectively,which are separated by completely different pollination syndromes.Transcriptome-based nuclear and plastome datasets indicate that these two lineages are isolated,with only weak ancient gene flow between them.Within each lineage,several taxa with incomplete isolation have diverged,as indicated by weak genetic structure,strong gene flow,and conflicts between nuclear and chloroplast phylogenies,especially in the trumpet lineage.Although these taxa are not entirely independent,our evidence indicates that they are diverging,with recent gene flow disappearing and multiple isolation strategies emerging,such as differences in flowering time and niche specialization.Taken together,our findings suggest that species divergence and maintenance in Lilium are driven by a combination of adaptive and non-adaptive processes,highlighting the complex interplay of historical climate changes,ecological adaptation,and gene flow in shaping biodiversity within this genus.
基金supported by the Natural Science Foundation of Fujian Province(No.2020J06008)for Distinguished Young Scholarsthe Fujian Provincial Central Guided Local Science and Technology Development Special Project(No.2022L3078).
文摘The occurrence of geogenic arsenic(As)in groundwater is a global public health concern.However,there remain large gaps in groundwater As data,making it difficult to identify non-compliant domestic wells,partly due to lack of low-cost methods capable of rapid As analysis.Therefore,the development of high through-put and reliable on-site determination methods for inorganic As is essential.Herein,a portable automated analyzer was developed for the determination of arsenite(As(Ⅲ)),arsenate(As(Ⅴ))and phosphate in As contaminated groundwater based on a previously adapted method for molybdenum blue spectrophotometry.After the optimization of the chemical reactions and flow manifold,the system demonstrated a high sample through-put(4.8/h for As(Ⅲ),As(Ⅴ)and phosphate analysis),allowing this system to screen 125 samples in 24 h.Other advantages include low operational costs(0.3 CNY per sample),appropriate sensitivity for contaminated groundwater(detection limits of 4.7μg/L,8.3μg/L and 5.4μg/L for As(Ⅲ),As(Ⅴ)and phosphate,respectively),good linearity(R^(2)>0.9996 at As concentrations up to 1600μg/L)and high precision(relative standard deviations of 3.5% and 2.8% for As(Ⅲ)and As(Ⅴ),respectively).The portable system was successfully used for As speciation analysis in 5 groundwater samples collected from multi-level wells at Yinchuan Plain,northwestern China,with total As concentrations ranging from 75.7 to 295.0μg/L,independently assessing As speciation,providing a promising novel method for the rapid on-site screening of As in tens of millions of domestic wells worldwide.
基金supported by the National Natural Science Foundation of China(No.22074058,S.Li).
文摘Algal copper uptake(i.e.,Cu bioavailability)in the euphotic zone plays a vital role in algal photosynthesis and respiration,affecting the primary productivity and the source and sink of atmospheric carbon.Algal Cu uptake is controlled by natural dissolved organic Cu(DOCu)speciation(i.e.,complexed with the dissolved organic matter)that conventionally could be tested by model prediction or molecular-level characterizations in the lab,while DOCu uptake are hardly directly assessed.Thus,the new chemistrybiology insight into the mechanisms of the Cu uptake process in algae is urgent.The DOCu speciation transformation(organic DOCu to free Cu(II)ions),enzymatic reduction-induced valence change(reduction of free Cu(II)to Cu(I)ions),and algal Cu uptake at the algae-water interface are imitated.Herein,an intelligent system with DOCu colorimetric sensor is developed for real-time monitoring of newly generated Cu(I)ions.Deep learning with whole sample image-based characterization and powerful feature extraction capabilities facilitates colorimetric measurement.In this context,the Cu bioavailability with 7 kinds of organic ligands(e.g.,amino acids,organic acids,carbohydrates)can be predicted by the mimetic intelligent biosensor within 15.0min,i.e.,the DOCu uptake and speciation is successfully predicted and streamlined by the biomimetic approach.
基金supported by the National Key Research and Development Program of China(No.2021YFC1809205)the Beijing Natural Science Foundation(No.8232029)the National Natural Science Foundation of China(No.41501336).
文摘Cadmium(Cd)and arsenic(As)co-contamination has threatened rice production and food safety.It is challenging to mitigate Cd and As contamination in rice simultaneously due to their opposite geochemical behaviors.Mg-loaded biochar with outstanding adsorption capacity for As and Cd was used for the first time to remediate Cd/As contaminated paddy soils.In addition,the effect of zero-valent iron(ZVI)on grain As speciation accumulation in alkaline paddy soils was first investigated.The effect of rice straw biochar(SC),magnesiumloaded rice straw biochar(Mg/SC),and ZVI on concentrations of Cd and As speciation in soil porewater and their accumulation in rice tissueswas investigated in a pot experiment.Addition of SC,Mg/SC and ZVI to soil reduced Cd concentrations in rice grain by 46.1%,90.3%and 100%,and inorganic As(iAs)by 35.4%,33.1%and 29.1%,respectively,and reduced Cd concentrations in porewater by 74.3%,96.5%and 96.2%,respectively.Reductions of 51.6%and 87.7%in porewater iAs concentrationswere observed with Mg/SC and ZVI amendments,but notwith SC.Dimethylarsinic acid(DMA)concentrations in porewater and grain increased by a factor of 4.9 and 3.3,respectively,with ZVI amendment.The three amendments affected grain concentrations of iAs,DMA and Cd mainly by modulating their translocation within plant and the levels of As(Ⅲ),silicon,dissolved organic carbon,iron or Cd in porewater.All three amendments(SC,Mg/SC and ZVI)have the potential to simultaneously mitigate Cd and iAs accumulation in rice grain,although the pathways are different.
基金Project(51274257)supported by the National Natural Science Foundation of ChinaProject(U1232103)supported by the Joint Funds of National Natural Science Foundation of China and Large Scientific Facility Foundation of Chinese Academy of SciencesProject(VR-12419)supported by the Beijing Synchrotron Radiation Facility Public User Program
文摘The utilization and speciation transformation of α-S8 and μ-S by the typical mesophilic acidophilic strain Acidithiobacillus ferrooxidans ATCC 23270 were investigated.A.ferrooxidans cells first acclimated to the energy source α-S8 or μ-S,respectively.The results of cell growth and sulfur oxidation behavior showed that the strain grown on α-S8 entered slowly（about 1 d later） into the exponential phase,while grew faster in the exponential phase and attained higher maximal cell density and lower p H value than that on μ-S.After bio-corrosion,both of the two sulfur samples were evidently eroded and modified by A.ferrooxidans cells.After growth of A.ferrooxidans,the surface composition of amorphous μ-S became 63.1% μ-S and 36.9% α-S8,and that of orthorhombic α-S8 became 68.3% α-S8 and 31.7% μ-S,while the surface compositions of α-S8 and μ-S in sterile experiment were not changed,indicating that these two elemental sulfur species can be interconverted by A.ferrooxidans.
基金Supported by National Natural Science Foundation of China(30600806)Science and Technology Project of Higher Education of Ningxia Hui Autonomous Region (NJ0626)~~
文摘[Objective]The aim was to analyze the primary speciation of 6 microelements in Glycyrrhiza uralensis Fisch. and provide theoretical basis for explaining pharmacodynamic principle of liquorice and discussing quality control of liquorice planting. [Method]The 6 elements Cu,Zn,Ca,Fe,Mg and Mn in roots of G.uralensis were extracted based on traditional decoction method and were separated into water-soluble state and suspension state by micro porous filtering film. The elements in water-soluble state were detected by flame atomic adsorption spectrophotometry （FAAS）. [Result]The results showed that extractive rates of the elements were in the range of 1.71%-60.06%,and immerse-residue ratio in 0.018 3-1.682 0; the results also indicated that the immerse-residue ratio of Zn was biggest （1.68）,Zn played an important medical role and might be considered as the best characteristic element in G.uralensis; the recoveries of the elements were ranged from 95.72% to 103.15% and relative standard deviations （RSD） were less than 2.38%. [Conclusion]Because of its high accuracy,FAAS method is feasible for analyzing primary speciation of microelements in G.uralensis.
基金This work was supported by the Cooperative State Research, Education, and Extension Service, US Department of Agriculture, under project number ILLU 875-952, the National Science Foundation （DEB 0953716 and IOS 1701676）, and the University of IlLinois. The treatment of animals was approved by the Institutional Animal Care and Use Committee under protocol No. 14097.
文摘Selection against hybridization can cause mating traits to diverge between species in sympatry via reproductive character displacement （RCD）. Additionally, selection against interspecific fighting can cause aggressive traits to diverge between sympatric species via agonistic character displacement （ACD）. By directly affecting conspecific recognition traits, RCD and ACD between species can also incidentally cause divergence in mating and fighting traits among populations within a species [termed cascade RCD （CRCD） and cascade ACD]. Here, we demonstrate patterns consistent with male-driven RCD and ACD in 2 groups of darters （orangethroat darter clade Ceasia and rainbow darter Etheostoma caeruleum）. In both groups, males that occur in sympatry （between Ceasia and E. caeruleum） have higher levels of preference for mating and fighting with conspecifics over heterospecifics than do males from allopatry. This is consistent with RCD and ACD. We also found patterns consistent with CRCD and cascade ACD among species of Ceasia. Ceasia males that are sympatric to E. caeruleum （but allopatric to one another） also have heightened preferences for mat- ing and fighting with conspecific versus heterospecific Ceasia. In contrast, Ceasia males that are allopatric to E. caeruleum readily mate and fight with heterospecific Ceasia. We suggest that RCD and ACD between Ceasia and E. caeruleum has incidentally led to divergence in mating and fighting traits among Ceasia species. This study is unique in that male preferences evolve via both RCD （male preference for conspecific females） and ACD （male preference to fight conspecific males） which leads to subsequent divergence among allopatric lineages.
基金Acknowledgments I would like to thank Nicolas Bierne for the opportunity of contributing to the Special Column： Population Genomics in the Sea. Helpful comments on the manuscript were provided by Nicolas Bierne and two anonymous reviewers.Partial funding for the work described on strongylocentrotid sea urchins was provided by the Natinal Science Foundation （DEB-1011061 ）.
文摘A growing number of genes responsible for reproductive incompatibilities between species （barrier loci） exhibit the signals of positive selection. However, the possibility that genes experiencing positive selection diverge early in speciation and commonly cause reproductive incompatibilities has not been systematically investigated on a genome-wide scale. Here, I outline a research program for studying the genetic basis of speciation in broadcast spawning marine invertebrates that uses a priori genome-wide information on a large, unbiased sample of genes tested for positive selection. A targeted sequence capture approach is proposed that scores single-nucleotide polymorphisms （SNPs） in widely separated species populations at an early stage of allopatric divergence. The targeted capture of both coding and non-coding sequences enables SNPs to be characterized at known locations across the genome and at genes with known selective or neutral histories. The neutral coding and non-coding SNPs provide robust background distributions for identifying Fsm-outliers within genes that can, in principle, identify specific mutations experiencing diversifying selection. If natural hybridization occurs between species, the neutral coding and noncoding SNPs can provide a neutral admixture model for genomic clines analyses aimed at finding genes exhibiting strong blocks to introgression. Strongylocentrotid sea urchins are used as a model system to outline the approach but it can be used for any group that has a complete reference genome available.
基金Acknowledgments We thank Kevin Burls, Alan de Queiroz, Chris Feldman, Angela Hornsby, Peter Murphy, Derek Roff, and an anonymous reviewer for insightful criticisms and comments on earlier versions of this manuscript.Funding was provided in part by a National Science Foundation grant to MDM （DEB-0952946） and by an ND EPSCoR grant to NAD.
文摘Groups of organisms-whether multiple species or populations of a single species-can differ in several non-exclusive ways. For example, groups may have diverged phenotypically, genetically, or in the evolutionary responses available to them. We tested for the latter of these-response di- vergence-between 2 species of woodrats： Neotoma fuscipes and Neotoma macrotis. Based on random skewers analyses we found that, despite being well differentiated both phenotypically and genetically, N. fuscipes and N. macrotis appear to be diverging along a shared evolutionary trajec- tory （ro = 0.895, P= 0.114）. Because these species are currently in secondary contact, their phenotypic evolution being along a shared evolutionary axis has important implications. In particular, that their response to selection arising from interspecific interactions will be constrained along the same evolutionary trajectory may reduce the potential for reinforcing selection to maintain species boundaries.
