In recent years,there has been considerable exploration into methods aimed at enhancing the regenerative capacity of transplanted and/or tissue-resident cells.Biomaterials,in particular,have garnered significant inter...In recent years,there has been considerable exploration into methods aimed at enhancing the regenerative capacity of transplanted and/or tissue-resident cells.Biomaterials,in particular,have garnered significant interest for their potential to serve as natural scaffolds for cells.In this editorial,we provide commentary on the study by Wang et al,in a recently published issue of World J Stem Cells,which investigates the use of a decellularized xenogeneic extracellular matrix(ECM)derived from antler stem cells for repairing osteochondral defects in rat knee joints.Our focus lies specifically on the crucial role of biological scaffolds as a strategy for augmenting stem cell potential and regenerative capabilities,thanks to the establishment of a favorable microenvironment(niche).Stem cell differen-tiation heavily depends on exposure to intrinsic properties of the ECM,including its chemical and protein composition,as well as the mechanical forces it can generate.Collectively,these physicochemical cues contribute to a bio-instructive signaling environment that offers tissue-specific guidance for achieving effective repair and regeneration.The interest in mechanobiology,often conceptualized as a form of“structural memory”,is steadily gaining more validation and momen-tum,especially in light of findings such as these.展开更多
To investigate the dominant species and interspecific association in the phytoplankton community of the Feiyun River basin in Zhejiang Province,East China,the main stream and the Shanxi Zhaoshandu Reservoir in the dow...To investigate the dominant species and interspecific association in the phytoplankton community of the Feiyun River basin in Zhejiang Province,East China,the main stream and the Shanxi Zhaoshandu Reservoir in the downstream were chosen as the study area,for which 22 sampling sites were designated.Sampling was conducted in September 2021,January,May,and July 2022.Phytoplankton species were identified from both quantitative samples and in-vivo observations.Phytoplankton was quantified by direct counting.Results show that there were 98 species belonging to 6 phyla and 78 genera.In addition,to clarify the niches of the dominant phytoplankton species and their interspecific association,the dominance index was calculated,and a comprehensive analysis was conducted including niche width,niche overlap value,ecological response rate,overall association,chi-square test,and the stability.The phytoplankton community exhibited characteristics of a Cyanobacteria-Chlorophyta-Diatom type community,showing higher diversity in spring and lower diversity in summer.Among 11 dominants phytoplankton species from 3 phyla,both frequency and dominance degree varied seasonally,of which Microcystis sp.was the dominant species in Spring,Autumn,and Winter.The niche widths of the dominant species ranged from 0.234 to 0.933,and were categorized into three groups.The niche overlap values of the 11 dominant species ranged from 0.359 to 0.959,exhibiting significant seasonal differences-highest in winter followed by autumn,spring,and summer in turn.The overall correlation among dominant species in all four seasons revealed a non-significant negative association,resulting in an unstable community structure.A significant portion(84.2%)of species pairs displayed positive associations,suggesting a successional pattern where Diatoms dominated while other dominant species shared resources and space.Despite this pattern,stability measurements indicated that the dominant species community remained unstable.Therefore,careful monitoring is recommended for potential water environment issues arising from abnormal proliferation of dominant species in the watershed during winter.This research built a theoretical foundation with a data support to the early warning of eutrophication and provided a reference for water resources management in similar watersheds along the eastern coast of China.展开更多
Post-disaster recovery and reconstruction provide an effective way to reduce the disaster vulnerability of, and promote leapfrog development in, an affected area. To date, studies that have used administrative boundar...Post-disaster recovery and reconstruction provide an effective way to reduce the disaster vulnerability of, and promote leapfrog development in, an affected area. To date, studies that have used administrative boundaries to investigate the reconstruction of settlement space have not been able to clearly define the real boundaries of land use changes or quantify the degree of response to the ‘Build-Back-Better’ initiative, and have lacked any consideration of the fourth reconstruction stage–development period(10 years). This study constructed a mountain settlement niche and analyzed the characteristics, spatial reconstruction, and drivers of rural settlements during 2009–2019 in the upper reaches of the Minjiang River, southwest China. The results showed the following:(1) Natural factors were the basis for the formation and development of mountain settlement niches. The scale of the settlement niche and its land use structure depended on the physical geography features and the ethnic farming and grazing traditions. The settlement niche provided a realistic boundary for the spatial reconstruction.(2) The layout of residential land around cropland was the common feature of the mountain settlement niche. Of all the land use types, the roads and rural residential lands showed the most change over the 10 years;13,860 residential patches increased in size and 4,742 patches were abandoned.(3) The area of orchards, planted to reconstruct the economy in the mountains, increased by nearly 2.5 times.(4) Collapses, landslides, and debris flow disasters and the ecological red line influenced the spatial reconstruction. While the main focus of post-disaster recovery is spatial reconstruction, initiatives should include economic and spiritual recovery, and should also achieve sustainable development of the region.展开更多
Liver transplantation(LT)is the standard therapy for individuals afflicted with end-stage liver disease.Despite notable advancements in LT technology,the incidence of early allograft dysfunction(EAD)remains a critical...Liver transplantation(LT)is the standard therapy for individuals afflicted with end-stage liver disease.Despite notable advancements in LT technology,the incidence of early allograft dysfunction(EAD)remains a critical concern,exacerbating the current organ shortage and detrimentally affecting the prognosis of recipients.Unfortunately,the perplexing hepatic heterogeneity has impeded characterization of the cellular traits and molecular events that contribute to EAD.Herein,we constructed a pioneering single-cell transcriptomic landscape of human transplanted livers derived from non-EAD and EAD patients,with 12 liver samples collected from 7 donors during the cold perfusion and portal reperfusion stages.Comparison of the 75231 cells of non-EAD and EAD patients revealed an EAD-associated immune niche comprising mucosal-associated invariant T cells,granzyme B^(+)(GZMB^(+))granzyme K^(+)(GZMK^(+))natural killer cells,and S100 calcium binding protein A12^(+)(S100A12^(+))neutrophils.Moreover,we verified this immune niche and its association with EAD occurrence in two independent cohorts.Our findings elucidate the cellular characteristics of transplanted livers and the EAD-associated pathogenic immune niche at the single-cell level,thus,offering valuable insights into EAD onset.展开更多
Meroplankton play a crucial role in both benthic and pelagic ecosystems.Existing quantitative research on estimating the quantities of meroplankton groups is both underrepresented and inaccurate.To investigate and eva...Meroplankton play a crucial role in both benthic and pelagic ecosystems.Existing quantitative research on estimating the quantities of meroplankton groups is both underrepresented and inaccurate.To investigate and evaluate the influence of varying mesh sizes(505 and 160μm)on the sampling efficiency of meroplankton,we conducted an examination using two commonly used plankton nets during the spring season in the Southern Yellow Sea(SYS).Our study revealed a total of 12 meroplankton groups,with 9 groups identified in the 505-μm mesh nets and 11 groups in the 160-μm mesh nets.The results demonstrated the superior collection efficiency of the 160-μm net compared to the 505-μm net across the majority of meroplankton groups.Furthermore,we focused on exploring the abundance,distribution patterns,and realized niches of meroplankton collected by the two mesh size nets,and observed that the distribution of meroplankton closely resembled the distribution of possible benthic adults in the SYS.Correlation analysis of the six dominant groups collected in the 160-μm mesh nets revealed that seawater temperature and salinity emerged as the key environmental factors driving variations in meroplankton abundance within the SYS.This study also found that a smaller mesh size net does not necessarily capture meroplankton more comprehensively.A comprehensive understanding of the ecological characteristics of meroplankton requires the combination of two types of nets for research.Our research significantly advances our understanding of the quantification,abundance,and distribution of meroplankton,serving as a valuable contribution to the broader landscape of detailed quantitative meroplankton studies.展开更多
It is still a huge challenge for traditional Pareto-dominatedmany-objective optimization algorithms to solve manyobjective optimization problems because these algorithms hardly maintain the balance between convergence...It is still a huge challenge for traditional Pareto-dominatedmany-objective optimization algorithms to solve manyobjective optimization problems because these algorithms hardly maintain the balance between convergence and diversity and can only find a group of solutions focused on a small area on the Pareto front,resulting in poor performance of those algorithms.For this reason,we propose a reference vector-assisted algorithmwith an adaptive niche dominance relation,for short MaOEA-AR.The new dominance relation forms a niche based on the angle between candidate solutions.By comparing these solutions,the solutionwith the best convergence is found to be the non-dominated solution to improve the selection pressure.In reproduction,a mutation strategy of k-bit crossover and hybrid mutation is used to generate high-quality offspring.On 23 test problems with up to 15-objective,we compared the proposed algorithm with five state-of-the-art algorithms.The experimental results verified that the proposed algorithm is competitive.展开更多
The corneal epithelium is composed of stratified squamous epithelial cells on the outer surface of the eye,which acts as a protective barrier and is critical for clear and stable vision.Its continuous renewal or wound...The corneal epithelium is composed of stratified squamous epithelial cells on the outer surface of the eye,which acts as a protective barrier and is critical for clear and stable vision.Its continuous renewal or wound healing depends on the proliferation and differentiation of limbal stem cells(LSCs),a cell population that resides at the limbus in a highly regulated niche.Dysfunction of LSCs or their niche can cause limbal stem cell deficiency,a disease that is manifested by failed epithelial wound healing or even blindness.Nevertheless,compared to stem cells in other tissues,little is known about the LSCs and their niche.With the advent of single-cell RNA sequencing,our understanding of LSC characteristics and their microenvironment has grown considerably.In this review,we summarized the current findings from single-cell studies in the field of cornea research and focused on important advancements driven by this technology,including the heterogeneity of the LSC population,novel LSC markers and regulation of the LSC niche,which will provide a reference for clinical issues such as corneal epithelial wound healing,ocular surface reconstruction and interventions for related diseases.展开更多
BACKGROUND Scar formation and loss of cutaneous appendages are the greatest challenges in cutaneous wound healing.Previous studies have indicated that antler reserve mesenchyme(RM)cells and their conditioned medium im...BACKGROUND Scar formation and loss of cutaneous appendages are the greatest challenges in cutaneous wound healing.Previous studies have indicated that antler reserve mesenchyme(RM)cells and their conditioned medium improved regenerative wound healing with partial recovery of cutaneous appendages.AIM To develop hydrogels from the antler RM matrix(HARM)and evaluate the effect on wound healing.METHODS We prepared the hydrogels from the HARM via enzymatic solubilization with pepsin.Then we investigated the therapeutic effects of HARM on a full-thickness cutaneous wound healing rat model using both local injections surrounding the wound and topical wound application.RESULTS The results showed that HARM accelerated wound healing rate and reduced scar formation.Also,HARM stimulated the regeneration of cutaneous appendages and blood vessels,and reduced collagen fiber aggregation.Further study showed that these functions might be achieved via creating a fetal-like niche at the wound site.The levels of fetal wound healing-related genes,including Collagen III and TGFβ3 treated with HARM were all increased,while the expression levels of Collagen I,TGFβ1,and Engrailed 1 were decreased in the healing.Moreover,the number of stem cells was increased in the fetal-like niche created by HARM,which may contribute to the regeneration of cutaneous appendages.CONCLUSION Overall,we successfully developed an injectable hydrogel made from antler RM matrix for the regenerative repair of full-thickness cutaneous wounds.We uncovered the molecular mechanism of the hydrogels in promoting regenerative wound healing,and thus pave the way for HARM to be developed for the clinic use.展开更多
The premetastatic niches(PMN)formed by primary tumor-derived molecules regulate distant organs and tissues to further favor tumor colonization.Targeted PMN therapy may prevent tumor metastasis in the early stages,whic...The premetastatic niches(PMN)formed by primary tumor-derived molecules regulate distant organs and tissues to further favor tumor colonization.Targeted PMN therapy may prevent tumor metastasis in the early stages,which is becoming increasingly important.At present,there is a lack of in-depth understanding of the cellular and molecular characteristics of the PMN.Here,we summarize current research advances on the cellular and molecular characteristics of the PMN.We emphasize that PMN intervention is a potential therapeutic strategy for early prevention of tumor metastasis,which provides a promising basis for future research and clinical application.展开更多
Plant-associated microbes represent a key determinant of plant fitness through acquiring nutrients,promoting growth,and resisting to abiotic and biotic stresses.However,an extensive characterization of the bacterial a...Plant-associated microbes represent a key determinant of plant fitness through acquiring nutrients,promoting growth,and resisting to abiotic and biotic stresses.However,an extensive characterization of the bacterial and fungal microbiomes present in different plant compartments of soybean in field conditions has remained elusive.In this study,we investigated the effects of four niches(roots,stems,leaves,and pods),four genotypes(Andou 203,Hedou 12,Sanning 16,and Zhonghuang 13),and three field locations(Jining,Suzhou,and Xuzhou)on the diversity and composition of bacterial and fungal communities in soybean using 16S and internal transcribed spacer rRNA amplicon sequencing,respectively.The soybean microbiome significantly differed across organs.Host genotypes explained more variation in stem bacterial community composition and leaf fungal community composition.Field location significantly affected the composition of bacterial communities in all compartments and the effects were stronger in the root and stem than in the leaf and pod,whereas field location explained more variation in stem and leaf fungal community composition than in the root and pod.The relative abundances of potential soybean fungal pathogens also differed among host organs and genotypes,reflecting the niches of these microbes in the host and probably their compatibility to the host genotypes.Systematic profiling of the microbiome composition and diversity will aid the development of plant protection technologies to benefit soybean health.展开更多
Polyploidy after hybridization between species can lead to immediate post-zygotic isolation,causing saltatory origin of new species.Although the incidence of polyploidization in plants is high,it is thought that a new...Polyploidy after hybridization between species can lead to immediate post-zygotic isolation,causing saltatory origin of new species.Although the incidence of polyploidization in plants is high,it is thought that a new polyploid lineage can succeed only if it establishes a new ecological niche divergent from its progenitor lineages.We tested the hypothesis that Rhodiola integrifolia from North America is an allopolyploid produced by R. rhodantha and R.rosea and determined whether its survival can be explained by the niche divergence hypothesis.To this end,we sequenced two low-copy nuclear genes(ncpGS and rpb2) in a phylogenetic analysis of 42 Rhodiola species and tested for niche equivalency and similarity using Schoener’s D as the index of niche overlap.Our phylogeny-based approach showed that R integrifolia possesses alleles from both R. rhodantha and rosea Dating analysis showed that the hybridization event that led to R.integrifolia occurred ca.1.67 Mya and niche modeling analysis showed that at this time,both R.rosea and R.rhodantha may have been present in Beringia,providing the opportunity for the hybridization event.We also found that the niche of R.integrifolia differs from that of its progenitors in both niche breadth and optimum.Taken together,these results confirm the hybrid origin of R.integrifolia and support the niche divergence hypothesis for this tetraploid species.Our results underscore the fact that lineages with no current overlapping distribution could produce hybrid descendants in the past,when climate oscillations made their distributions overlap.展开更多
Drivers of bird niche separation in temperate primeval forests have not yet been determined,due to the low number of intact forest sites.Here,we analyzed the general patterns of niche usage on trees by birds’assembla...Drivers of bird niche separation in temperate primeval forests have not yet been determined,due to the low number of intact forest sites.Here,we analyzed the general patterns of niche usage on trees by birds’assemblages.We tested how tree species affect the sharing of space in an assemblage of birds and their level of specialization.We conducted our study in the Białowieża primeval forest(NE Poland).During two breeding seasons,we observed bird positions on trees,divided into three vertical and six horizontal zones in 768 observation points.Based on the interaction networks framework we calculated the Kullback-Leibler distance d′as a metric of species specialization and the resource range RR index,which estimates the species’specificity based on the fraction of space utilized with a non-zero performance.The d′index was the highest in the lower understory for all parts of the tree on the basis of the position from the trunk.The RR index was the highest in the lower understory for all parts based on the position from the trunk.Regarding the tree species,the lowest d′index was observed in all tree species together,and hornbeam,whereas the highest in oak.At the tree species level,the RR index was the lowest for hornbeam.We show tree species importance in forest space sharing in the case of bird assemblages.Hornbeam,alder,and spruce are universal species that were used by birds almost entirely.In contrast,oak,lime,and maple were only partially used.Tree species with less complex structures could shape bird assemblages,as they could offer birds much fewer niches to realize.Therefore,we showed that high specialization and niche separation are drivers of high bird diversity.Consequently maintaining a diverse stand structure is crucial for biodiversity conservation.展开更多
The ecological-niche models for two sympatric species,Eremias lineolata(Nikolsky,1897)and Eremias scripta(Strauch,1867),reveal evidence of spatial and temporal disjunction in the actual niches of both species.Eremias ...The ecological-niche models for two sympatric species,Eremias lineolata(Nikolsky,1897)and Eremias scripta(Strauch,1867),reveal evidence of spatial and temporal disjunction in the actual niches of both species.Eremias lineolata demonstrates a wide range of adaptations and,at the same time,has a greater need for winter precipitation and minimal temperature than E.scripta.Possible explanations for the thermal diversity of both species are provided.Thermal variables(monthly temperatures,monthly solar radiation,etc.)are traditionally important for ectotherm animals.Interestingly,as many as half of the key variables in both species are related to different aspects of environmental water balance(precipitation,air humidity,vapor pressure).There are several ways in which moisture may impact the lizard’s life cycle.Soil humidity is related to soil temperature and may be important during winter hibernation.In summer,soil humidity may support successful embryogenesis.Precipitation during the warm months is a key factor in maintaining the moisture content of the soil.In winter,snow cover provides a better thermal balance of the soil’s top layers where winter shelters are housed.Ecological niche modeling(ENM)is an interdisciplinary approach combining the geographical,climatic,ecological,and biological aspects of the wellbeing of species.This interdisciplinary approach lifts biological studies onto a new,integrative level,providing a comprehensive view on species biology and answering the questions that might not be answered if the traditional methods for studying animals were used alone.展开更多
Microorganisms play an important role in plant growth,health and ecological function.It is necessary to explore the microbial community because of the significant ecological and economic value of apples(Malus x domest...Microorganisms play an important role in plant growth,health and ecological function.It is necessary to explore the microbial community because of the significant ecological and economic value of apples(Malus x domestica).However,the related bacterial communities in different ecological habitats are not clear in the unique scion/rootstock combinations of apples.In this study,the Illumina Miseq platform was used to analyze the bacterial communities in different niches(bulk soil,rhizosphere soil and roots)of two scion/rootstock combinations[Fuji/Malus xiaojinensis Cheng et Jiang(Mx)and Fuji/Malus baccata(L.)Borkh.(Mb)].The relationship between the microbial community,soil properties,and plant characters was explored.The results showed that the diversity of the bacterial community decreased from bulk soil to rhizosphere soil and then to roots.In addition,at the phylum level,Proteobacteria,Actinobacteria and Acitinobacteria were dominant and had notable divergence in different ecological niches.Distinct niches had remarkable effects on the diversity and composition of the bacterial community according to PCoA.The rootstock genotype had an effect on the bacterial composition but no effect on the diversity.pH,soil organic matter(SOM),alkaline hydrolyzable nitrogen(AN)were the main factor affecting the structure of bacterial community in rhizosphere soil,as shown by Pearson analysis.Bacteria taxa in the roots were affected by starch,fructose,sucrose and sorbitol.This study showed the microbial community structure in different ecological niches of different scion/rootstock combinations and provided some evidence for understanding the microbial-plant interaction of apple rootstocks.展开更多
Several crucial stromal cell populations regulate hematopoiesis and malignant diseases in bone marrow niches.Precise regulation of these cell types can remodel niches and develop new therapeutics.Multiple nanocarriers...Several crucial stromal cell populations regulate hematopoiesis and malignant diseases in bone marrow niches.Precise regulation of these cell types can remodel niches and develop new therapeutics.Multiple nanocarriers have been developed to transport drugs into the bone marrow selectively.However,the delivery efficiency of these nanotherapeutics into crucial niche cells is still unknown,and there is no method available for predicting delivery efficiency in these cell types.Here,we constructed a three-dimensional bone marrow niche composed of three crucial cell populations:endothelial cells(ECs),mesenchymal stromal cells(MSCs),and osteoblasts(OBs).Mimetic niches were used to detect the cellular uptake of three typical drug nanocarriers into ECs/MSCs/OBs in vitro.Less than 5%of nanocarriers were taken up by three stromal cell types,and most of themwere located in the extracellular matrix.Delivery efficiency in sinusoidal ECs,arteriole ECs,MSCs,and OBs in vivo was analyzed.The correlation analysis showed that the cellular uptake of three nanocarriers in crucial cell types in vitro is positively linear correlated with its delivery efficiency in vivo.The delivery efficiency into MSCs was remarkably higher than that into ECs and OBs,no matterwhat kind of nanocarrier.The overall efficiency into sinusoidal ECswas greatly lower than that into arteriole ECs.All nanocarriers were hard to be delivered into OBs(<1%).Our findings revealed that cell tropisms of nanocarriers with different compositions and ligand attachments in vivo could be predicted via detecting their cellular uptake in bone marrow niches in vitro.This study provided the methodology for niche-directed nanotherapeutics development.展开更多
This study aims to verify the concept of niches at multiple spatial scales in plant communities.To this end,we analyzed the niche characteristic of Rhododendron dauricum plant communities in Northeast China at three s...This study aims to verify the concept of niches at multiple spatial scales in plant communities.To this end,we analyzed the niche characteristic of Rhododendron dauricum plant communities in Northeast China at three spatial scales.At the local scale,we calculated the Importance Value(IV)of species in five communities in the north of the Da Hinggan Mountains.At the intermediate scale,we examined five communities in their entirety,calculated the niche breadth of the species,and integrated niche overlap and interspecific association to analyze interspecific relationships.Further,the generalized additive model(GAM)was used to analyze the impact of topography and soil factors on niche characteristics.At the regional scale,we analyzed the geographical distribution of dominant species of R.dauricum plant communities in Northeast China and used principal component analysis(PCA)to analyze the impact of geographical and climate factors on species distribution.The results show that at the local scale,the IV of the species in each community varies widely.At the intermediate scale,species with a wide niche breadth tend to have a high value for IV.Larix gmelinii,Betula platyphylla,R.dauricum,Ledum palustre,and Vaccinium vitis-idaea had a relatively wide niche breadth and a high niche overlap,and the interspecific associations were almost all positive.Elevation and soil nutrients were the most dominant environmental factors.At the regional scale,species with a wide niche breadth tend to have a wide range of distribution,and temperature and precipitation were the most dominant environmental factors.This study suggests that the niche characteristics at three scales are both related and different.Niche characteristics at the local scale were various and labile,and niche characteristics at the intermediate and regional scales were relatively regular.These results show some degree of consistency with previous studies from an evolutionary perspective.The action mechanisms of these communities are related to differences in the dominant environmental factors.In addition,the integration of niche overlap and interspecific association determine interspecific relationships more accurately.展开更多
An index of relative importance(IRI) was employed to screen for dominant fish in the waters surrounding the Taishan Islands, China, using data from four seasonal trawl surveys undertaken between 2012 and 2013. Niche b...An index of relative importance(IRI) was employed to screen for dominant fish in the waters surrounding the Taishan Islands, China, using data from four seasonal trawl surveys undertaken between 2012 and 2013. Niche breadth and niche overlap were measured using the Feinsinger and Morisita-Horn indices, respectively, and the characteristics and seasonal variations in the niches of dominant fish were assessed via non-metric multidimensional scaling(NMDS) and cluster analysis. A total of 80 fish species, including 16 dominant species, were recorded. Only A mblychaeturichthys hexanema was dominant in all seasons. According to niche breadth values and NMDS, the 16 dominant species were grouped into the following three types:(1) wide niche breadth species, including Cynoglossus macrolepidotus, A. hexanema, and Trypauchen vagina, among others;(2) medium niche breadth species, including Setipinna taty and Johnius belangerii; and(3) narrow niche breadth species, including A trobucca nibe and Coilia mystus. Most species with a wider niche breadth were demersal fish with a lower swimming capability and even distribution. The niche breadth of migrating fish was narrower than that of settled fish. At a given spatial scale, fish with stronger swimming capabilities had a narrower niche breadth. Niche overlap, which is associated with niche specialization, ranged from 0.000 to 0.886 and had an annual mean value of 0.314. In summer and autumn, niche overlap was relatively high within species of the Sciaenidae family and within species of the Gobiidae in autumn. Dif ferences in thermophily, feeding habits, food organism abundance/distribution and predator-prey relationships af fected the niche overlap of fish in this area. Cluster analysis revealed that species with the narrowest niche breadth and lowest niche overlap values usually displayed lower aggregation and greater distribution dif ferences compared with other species.展开更多
文摘In recent years,there has been considerable exploration into methods aimed at enhancing the regenerative capacity of transplanted and/or tissue-resident cells.Biomaterials,in particular,have garnered significant interest for their potential to serve as natural scaffolds for cells.In this editorial,we provide commentary on the study by Wang et al,in a recently published issue of World J Stem Cells,which investigates the use of a decellularized xenogeneic extracellular matrix(ECM)derived from antler stem cells for repairing osteochondral defects in rat knee joints.Our focus lies specifically on the crucial role of biological scaffolds as a strategy for augmenting stem cell potential and regenerative capabilities,thanks to the establishment of a favorable microenvironment(niche).Stem cell differen-tiation heavily depends on exposure to intrinsic properties of the ECM,including its chemical and protein composition,as well as the mechanical forces it can generate.Collectively,these physicochemical cues contribute to a bio-instructive signaling environment that offers tissue-specific guidance for achieving effective repair and regeneration.The interest in mechanobiology,often conceptualized as a form of“structural memory”,is steadily gaining more validation and momen-tum,especially in light of findings such as these.
基金Supported by the National Key Scientific Research Project(No.2018YFC1508200)the Postgraduate Research&Practice Innovation Program of Jiangsu Province(No.KYCX 23_0714)+1 种基金the China Scholarship Council(No.202206710066)the Construction Project of Wenzhou Hydrology High quality Development Pilot Zone(No.WZSW-GZLFZXXQ-202105)。
文摘To investigate the dominant species and interspecific association in the phytoplankton community of the Feiyun River basin in Zhejiang Province,East China,the main stream and the Shanxi Zhaoshandu Reservoir in the downstream were chosen as the study area,for which 22 sampling sites were designated.Sampling was conducted in September 2021,January,May,and July 2022.Phytoplankton species were identified from both quantitative samples and in-vivo observations.Phytoplankton was quantified by direct counting.Results show that there were 98 species belonging to 6 phyla and 78 genera.In addition,to clarify the niches of the dominant phytoplankton species and their interspecific association,the dominance index was calculated,and a comprehensive analysis was conducted including niche width,niche overlap value,ecological response rate,overall association,chi-square test,and the stability.The phytoplankton community exhibited characteristics of a Cyanobacteria-Chlorophyta-Diatom type community,showing higher diversity in spring and lower diversity in summer.Among 11 dominants phytoplankton species from 3 phyla,both frequency and dominance degree varied seasonally,of which Microcystis sp.was the dominant species in Spring,Autumn,and Winter.The niche widths of the dominant species ranged from 0.234 to 0.933,and were categorized into three groups.The niche overlap values of the 11 dominant species ranged from 0.359 to 0.959,exhibiting significant seasonal differences-highest in winter followed by autumn,spring,and summer in turn.The overall correlation among dominant species in all four seasons revealed a non-significant negative association,resulting in an unstable community structure.A significant portion(84.2%)of species pairs displayed positive associations,suggesting a successional pattern where Diatoms dominated while other dominant species shared resources and space.Despite this pattern,stability measurements indicated that the dominant species community remained unstable.Therefore,careful monitoring is recommended for potential water environment issues arising from abnormal proliferation of dominant species in the watershed during winter.This research built a theoretical foundation with a data support to the early warning of eutrophication and provided a reference for water resources management in similar watersheds along the eastern coast of China.
基金financially supported by the National Natural Science Foundation of China (Grant No. 42171085)The Second Tibetan Plateau Scientific Expedition and Research Program (STEP) (Grant No.2019QZKK0307)。
文摘Post-disaster recovery and reconstruction provide an effective way to reduce the disaster vulnerability of, and promote leapfrog development in, an affected area. To date, studies that have used administrative boundaries to investigate the reconstruction of settlement space have not been able to clearly define the real boundaries of land use changes or quantify the degree of response to the ‘Build-Back-Better’ initiative, and have lacked any consideration of the fourth reconstruction stage–development period(10 years). This study constructed a mountain settlement niche and analyzed the characteristics, spatial reconstruction, and drivers of rural settlements during 2009–2019 in the upper reaches of the Minjiang River, southwest China. The results showed the following:(1) Natural factors were the basis for the formation and development of mountain settlement niches. The scale of the settlement niche and its land use structure depended on the physical geography features and the ethnic farming and grazing traditions. The settlement niche provided a realistic boundary for the spatial reconstruction.(2) The layout of residential land around cropland was the common feature of the mountain settlement niche. Of all the land use types, the roads and rural residential lands showed the most change over the 10 years;13,860 residential patches increased in size and 4,742 patches were abandoned.(3) The area of orchards, planted to reconstruct the economy in the mountains, increased by nearly 2.5 times.(4) Collapses, landslides, and debris flow disasters and the ecological red line influenced the spatial reconstruction. While the main focus of post-disaster recovery is spatial reconstruction, initiatives should include economic and spiritual recovery, and should also achieve sustainable development of the region.
基金supported by the National Natural Science Foundation of China(82200725)the Innovation Team and Talents Cultivation Program of National Administration of Traditional Chinese Medicine(ZYYCXTD-D-202002)+4 种基金the Fundamental Research Funds for the Central Universities(226-2023-00114,226-2022-00226,and 226-2023-00059)the Key Program of National Natural Science Foundation of China(81930016)the Key Research and Development Program of China(2021YFA1100500)the Major Research Plan of the National Natural Science Foundation of China(92159202)the Ningbo Top Medical and Health Research Program(2022030309).
文摘Liver transplantation(LT)is the standard therapy for individuals afflicted with end-stage liver disease.Despite notable advancements in LT technology,the incidence of early allograft dysfunction(EAD)remains a critical concern,exacerbating the current organ shortage and detrimentally affecting the prognosis of recipients.Unfortunately,the perplexing hepatic heterogeneity has impeded characterization of the cellular traits and molecular events that contribute to EAD.Herein,we constructed a pioneering single-cell transcriptomic landscape of human transplanted livers derived from non-EAD and EAD patients,with 12 liver samples collected from 7 donors during the cold perfusion and portal reperfusion stages.Comparison of the 75231 cells of non-EAD and EAD patients revealed an EAD-associated immune niche comprising mucosal-associated invariant T cells,granzyme B^(+)(GZMB^(+))granzyme K^(+)(GZMK^(+))natural killer cells,and S100 calcium binding protein A12^(+)(S100A12^(+))neutrophils.Moreover,we verified this immune niche and its association with EAD occurrence in two independent cohorts.Our findings elucidate the cellular characteristics of transplanted livers and the EAD-associated pathogenic immune niche at the single-cell level,thus,offering valuable insights into EAD onset.
基金Supported by the Laoshan Laboratory(Nos.LSKJ 202203700,LSKJ 202203704,LSKJ 202204005)the National Natural Science Foundation of China(NSFC)(Nos.42076166,42130411)the NSFC Ship Time Sharing Project(No.42149901)。
文摘Meroplankton play a crucial role in both benthic and pelagic ecosystems.Existing quantitative research on estimating the quantities of meroplankton groups is both underrepresented and inaccurate.To investigate and evaluate the influence of varying mesh sizes(505 and 160μm)on the sampling efficiency of meroplankton,we conducted an examination using two commonly used plankton nets during the spring season in the Southern Yellow Sea(SYS).Our study revealed a total of 12 meroplankton groups,with 9 groups identified in the 505-μm mesh nets and 11 groups in the 160-μm mesh nets.The results demonstrated the superior collection efficiency of the 160-μm net compared to the 505-μm net across the majority of meroplankton groups.Furthermore,we focused on exploring the abundance,distribution patterns,and realized niches of meroplankton collected by the two mesh size nets,and observed that the distribution of meroplankton closely resembled the distribution of possible benthic adults in the SYS.Correlation analysis of the six dominant groups collected in the 160-μm mesh nets revealed that seawater temperature and salinity emerged as the key environmental factors driving variations in meroplankton abundance within the SYS.This study also found that a smaller mesh size net does not necessarily capture meroplankton more comprehensively.A comprehensive understanding of the ecological characteristics of meroplankton requires the combination of two types of nets for research.Our research significantly advances our understanding of the quantification,abundance,and distribution of meroplankton,serving as a valuable contribution to the broader landscape of detailed quantitative meroplankton studies.
基金supported by the National Natural Science Foundation of China(Grant No.61976101)the University Natural Science Research Project of Anhui Province(Grant No.2023AH040056)+4 种基金the Natural Science Research Project of Anhui Province(Graduate Research Project,Grant No.YJS20210463)the Funding Plan for Scientic Research Activities of Academic and Technical Leaders and Reserve Candidates in Anhui Province(Grant No.2021H264)the Top Talent Project of Disciplines(Majors)in Colleges and Universities in Anhui Province(Grant No.gxbjZD2022021)the University Synergy Innovation Program of Anhui Province,China(GXXT-2022-033)supported by the Innovation Fund for Postgraduates of Huaibei Normal University(Grant Nos.cx2022041,yx2021023,CX2023043).
文摘It is still a huge challenge for traditional Pareto-dominatedmany-objective optimization algorithms to solve manyobjective optimization problems because these algorithms hardly maintain the balance between convergence and diversity and can only find a group of solutions focused on a small area on the Pareto front,resulting in poor performance of those algorithms.For this reason,we propose a reference vector-assisted algorithmwith an adaptive niche dominance relation,for short MaOEA-AR.The new dominance relation forms a niche based on the angle between candidate solutions.By comparing these solutions,the solutionwith the best convergence is found to be the non-dominated solution to improve the selection pressure.In reproduction,a mutation strategy of k-bit crossover and hybrid mutation is used to generate high-quality offspring.On 23 test problems with up to 15-objective,we compared the proposed algorithm with five state-of-the-art algorithms.The experimental results verified that the proposed algorithm is competitive.
文摘The corneal epithelium is composed of stratified squamous epithelial cells on the outer surface of the eye,which acts as a protective barrier and is critical for clear and stable vision.Its continuous renewal or wound healing depends on the proliferation and differentiation of limbal stem cells(LSCs),a cell population that resides at the limbus in a highly regulated niche.Dysfunction of LSCs or their niche can cause limbal stem cell deficiency,a disease that is manifested by failed epithelial wound healing or even blindness.Nevertheless,compared to stem cells in other tissues,little is known about the LSCs and their niche.With the advent of single-cell RNA sequencing,our understanding of LSC characteristics and their microenvironment has grown considerably.In this review,we summarized the current findings from single-cell studies in the field of cornea research and focused on important advancements driven by this technology,including the heterogeneity of the LSC population,novel LSC markers and regulation of the LSC niche,which will provide a reference for clinical issues such as corneal epithelial wound healing,ocular surface reconstruction and interventions for related diseases.
基金Supported by the Natural Science Foundation of Jilin Province,No.YDZJ202301ZYTS508National Natural Science Foundation of China,No.U20A20403+2 种基金Doctoral Research Start-Up Fund of Changchun Sci-Tech University,No.202303Young Scientific and Technological Talents Support Project of Jilin Province,No.QT202203Strategic Research and Consulting Project of Chinese Academy of Engineering,No.JL2022-05.
文摘BACKGROUND Scar formation and loss of cutaneous appendages are the greatest challenges in cutaneous wound healing.Previous studies have indicated that antler reserve mesenchyme(RM)cells and their conditioned medium improved regenerative wound healing with partial recovery of cutaneous appendages.AIM To develop hydrogels from the antler RM matrix(HARM)and evaluate the effect on wound healing.METHODS We prepared the hydrogels from the HARM via enzymatic solubilization with pepsin.Then we investigated the therapeutic effects of HARM on a full-thickness cutaneous wound healing rat model using both local injections surrounding the wound and topical wound application.RESULTS The results showed that HARM accelerated wound healing rate and reduced scar formation.Also,HARM stimulated the regeneration of cutaneous appendages and blood vessels,and reduced collagen fiber aggregation.Further study showed that these functions might be achieved via creating a fetal-like niche at the wound site.The levels of fetal wound healing-related genes,including Collagen III and TGFβ3 treated with HARM were all increased,while the expression levels of Collagen I,TGFβ1,and Engrailed 1 were decreased in the healing.Moreover,the number of stem cells was increased in the fetal-like niche created by HARM,which may contribute to the regeneration of cutaneous appendages.CONCLUSION Overall,we successfully developed an injectable hydrogel made from antler RM matrix for the regenerative repair of full-thickness cutaneous wounds.We uncovered the molecular mechanism of the hydrogels in promoting regenerative wound healing,and thus pave the way for HARM to be developed for the clinic use.
基金Chinese Academy of Medical Sciences Innovation Fund for Medical Sciences(2021-I2M-1-013)the National Key Research and Development Program of China(2021YFF0702801,2022YFF0710705)+1 种基金the Special Research Fund for Central Universities,Peking Union Medical College(No.3332022182)Seed Fund for Youth Talent Training Program of Beijing Tongren Hospital Affiliated to Capital Medical University(2020-YJJ-ZZL-034).
文摘The premetastatic niches(PMN)formed by primary tumor-derived molecules regulate distant organs and tissues to further favor tumor colonization.Targeted PMN therapy may prevent tumor metastasis in the early stages,which is becoming increasingly important.At present,there is a lack of in-depth understanding of the cellular and molecular characteristics of the PMN.Here,we summarize current research advances on the cellular and molecular characteristics of the PMN.We emphasize that PMN intervention is a potential therapeutic strategy for early prevention of tumor metastasis,which provides a promising basis for future research and clinical application.
基金supported by grants from the earmarked fund for China Agriculture Research System(CARS004-PS14)the National Key R&D Program of China(2018YFD0201000)the Special Fund for Agroscientific Research in the Public Interest,China(201303018)。
文摘Plant-associated microbes represent a key determinant of plant fitness through acquiring nutrients,promoting growth,and resisting to abiotic and biotic stresses.However,an extensive characterization of the bacterial and fungal microbiomes present in different plant compartments of soybean in field conditions has remained elusive.In this study,we investigated the effects of four niches(roots,stems,leaves,and pods),four genotypes(Andou 203,Hedou 12,Sanning 16,and Zhonghuang 13),and three field locations(Jining,Suzhou,and Xuzhou)on the diversity and composition of bacterial and fungal communities in soybean using 16S and internal transcribed spacer rRNA amplicon sequencing,respectively.The soybean microbiome significantly differed across organs.Host genotypes explained more variation in stem bacterial community composition and leaf fungal community composition.Field location significantly affected the composition of bacterial communities in all compartments and the effects were stronger in the root and stem than in the leaf and pod,whereas field location explained more variation in stem and leaf fungal community composition than in the root and pod.The relative abundances of potential soybean fungal pathogens also differed among host organs and genotypes,reflecting the niches of these microbes in the host and probably their compatibility to the host genotypes.Systematic profiling of the microbiome composition and diversity will aid the development of plant protection technologies to benefit soybean health.
基金supported by the Fundamental Research Funds for the Central University of Shaanxi Normal University (GK202103077 to J.Q,Zhang)the National Natural Science Foundation of China(Grant nos.31870194,32070236)。
文摘Polyploidy after hybridization between species can lead to immediate post-zygotic isolation,causing saltatory origin of new species.Although the incidence of polyploidization in plants is high,it is thought that a new polyploid lineage can succeed only if it establishes a new ecological niche divergent from its progenitor lineages.We tested the hypothesis that Rhodiola integrifolia from North America is an allopolyploid produced by R. rhodantha and R.rosea and determined whether its survival can be explained by the niche divergence hypothesis.To this end,we sequenced two low-copy nuclear genes(ncpGS and rpb2) in a phylogenetic analysis of 42 Rhodiola species and tested for niche equivalency and similarity using Schoener’s D as the index of niche overlap.Our phylogeny-based approach showed that R integrifolia possesses alleles from both R. rhodantha and rosea Dating analysis showed that the hybridization event that led to R.integrifolia occurred ca.1.67 Mya and niche modeling analysis showed that at this time,both R.rosea and R.rhodantha may have been present in Beringia,providing the opportunity for the hybridization event.We also found that the niche of R.integrifolia differs from that of its progenitors in both niche breadth and optimum.Taken together,these results confirm the hybrid origin of R.integrifolia and support the niche divergence hypothesis for this tetraploid species.Our results underscore the fact that lineages with no current overlapping distribution could produce hybrid descendants in the past,when climate oscillations made their distributions overlap.
基金supported by the University of Natural Sciences and Humanities in Siedlce and the Institute of Dendrology,Polish Academy of Sciencesupport from the Foundation for Polish Science (FNP) from the START scholarship
文摘Drivers of bird niche separation in temperate primeval forests have not yet been determined,due to the low number of intact forest sites.Here,we analyzed the general patterns of niche usage on trees by birds’assemblages.We tested how tree species affect the sharing of space in an assemblage of birds and their level of specialization.We conducted our study in the Białowieża primeval forest(NE Poland).During two breeding seasons,we observed bird positions on trees,divided into three vertical and six horizontal zones in 768 observation points.Based on the interaction networks framework we calculated the Kullback-Leibler distance d′as a metric of species specialization and the resource range RR index,which estimates the species’specificity based on the fraction of space utilized with a non-zero performance.The d′index was the highest in the lower understory for all parts of the tree on the basis of the position from the trunk.The RR index was the highest in the lower understory for all parts based on the position from the trunk.Regarding the tree species,the lowest d′index was observed in all tree species together,and hornbeam,whereas the highest in oak.At the tree species level,the RR index was the lowest for hornbeam.We show tree species importance in forest space sharing in the case of bird assemblages.Hornbeam,alder,and spruce are universal species that were used by birds almost entirely.In contrast,oak,lime,and maple were only partially used.Tree species with less complex structures could shape bird assemblages,as they could offer birds much fewer niches to realize.Therefore,we showed that high specialization and niche separation are drivers of high bird diversity.Consequently maintaining a diverse stand structure is crucial for biodiversity conservation.
基金This research has been funded by the Science Committee of the Ministry of Education and Science of the Republic of Kazakhstan(No.AP08855831).
文摘The ecological-niche models for two sympatric species,Eremias lineolata(Nikolsky,1897)and Eremias scripta(Strauch,1867),reveal evidence of spatial and temporal disjunction in the actual niches of both species.Eremias lineolata demonstrates a wide range of adaptations and,at the same time,has a greater need for winter precipitation and minimal temperature than E.scripta.Possible explanations for the thermal diversity of both species are provided.Thermal variables(monthly temperatures,monthly solar radiation,etc.)are traditionally important for ectotherm animals.Interestingly,as many as half of the key variables in both species are related to different aspects of environmental water balance(precipitation,air humidity,vapor pressure).There are several ways in which moisture may impact the lizard’s life cycle.Soil humidity is related to soil temperature and may be important during winter hibernation.In summer,soil humidity may support successful embryogenesis.Precipitation during the warm months is a key factor in maintaining the moisture content of the soil.In winter,snow cover provides a better thermal balance of the soil’s top layers where winter shelters are housed.Ecological niche modeling(ENM)is an interdisciplinary approach combining the geographical,climatic,ecological,and biological aspects of the wellbeing of species.This interdisciplinary approach lifts biological studies onto a new,integrative level,providing a comprehensive view on species biology and answering the questions that might not be answered if the traditional methods for studying animals were used alone.
基金supported by the National Key Research and Development Program of China(2016YFD0201103)the earmarked fund for China Agriculture Research System(CARS-27)+1 种基金the construction of Beijing Science and Technology Innovation and Service Capacity in Top Subjects(CEFFPXM2019_014207_000032)the Key Laboratory of Beijing Municipality of Stress Physiology and Molecular Biology for Fruit Trees。
文摘Microorganisms play an important role in plant growth,health and ecological function.It is necessary to explore the microbial community because of the significant ecological and economic value of apples(Malus x domestica).However,the related bacterial communities in different ecological habitats are not clear in the unique scion/rootstock combinations of apples.In this study,the Illumina Miseq platform was used to analyze the bacterial communities in different niches(bulk soil,rhizosphere soil and roots)of two scion/rootstock combinations[Fuji/Malus xiaojinensis Cheng et Jiang(Mx)and Fuji/Malus baccata(L.)Borkh.(Mb)].The relationship between the microbial community,soil properties,and plant characters was explored.The results showed that the diversity of the bacterial community decreased from bulk soil to rhizosphere soil and then to roots.In addition,at the phylum level,Proteobacteria,Actinobacteria and Acitinobacteria were dominant and had notable divergence in different ecological niches.Distinct niches had remarkable effects on the diversity and composition of the bacterial community according to PCoA.The rootstock genotype had an effect on the bacterial composition but no effect on the diversity.pH,soil organic matter(SOM),alkaline hydrolyzable nitrogen(AN)were the main factor affecting the structure of bacterial community in rhizosphere soil,as shown by Pearson analysis.Bacteria taxa in the roots were affected by starch,fructose,sucrose and sorbitol.This study showed the microbial community structure in different ecological niches of different scion/rootstock combinations and provided some evidence for understanding the microbial-plant interaction of apple rootstocks.
基金support from the National Natural Science Foundation of China(81703713,82174095,82274364)Natural Science Foundation of Zhejiang Province grants(LZ23H290001,LZ22H290001)internal support from Zhejiang Chinese Medical University(2022GJYY011).
文摘Several crucial stromal cell populations regulate hematopoiesis and malignant diseases in bone marrow niches.Precise regulation of these cell types can remodel niches and develop new therapeutics.Multiple nanocarriers have been developed to transport drugs into the bone marrow selectively.However,the delivery efficiency of these nanotherapeutics into crucial niche cells is still unknown,and there is no method available for predicting delivery efficiency in these cell types.Here,we constructed a three-dimensional bone marrow niche composed of three crucial cell populations:endothelial cells(ECs),mesenchymal stromal cells(MSCs),and osteoblasts(OBs).Mimetic niches were used to detect the cellular uptake of three typical drug nanocarriers into ECs/MSCs/OBs in vitro.Less than 5%of nanocarriers were taken up by three stromal cell types,and most of themwere located in the extracellular matrix.Delivery efficiency in sinusoidal ECs,arteriole ECs,MSCs,and OBs in vivo was analyzed.The correlation analysis showed that the cellular uptake of three nanocarriers in crucial cell types in vitro is positively linear correlated with its delivery efficiency in vivo.The delivery efficiency into MSCs was remarkably higher than that into ECs and OBs,no matterwhat kind of nanocarrier.The overall efficiency into sinusoidal ECswas greatly lower than that into arteriole ECs.All nanocarriers were hard to be delivered into OBs(<1%).Our findings revealed that cell tropisms of nanocarriers with different compositions and ligand attachments in vivo could be predicted via detecting their cellular uptake in bone marrow niches in vitro.This study provided the methodology for niche-directed nanotherapeutics development.
基金Under the auspices of National Key Research and Development Program of China(No.2016YFC0500306)。
文摘This study aims to verify the concept of niches at multiple spatial scales in plant communities.To this end,we analyzed the niche characteristic of Rhododendron dauricum plant communities in Northeast China at three spatial scales.At the local scale,we calculated the Importance Value(IV)of species in five communities in the north of the Da Hinggan Mountains.At the intermediate scale,we examined five communities in their entirety,calculated the niche breadth of the species,and integrated niche overlap and interspecific association to analyze interspecific relationships.Further,the generalized additive model(GAM)was used to analyze the impact of topography and soil factors on niche characteristics.At the regional scale,we analyzed the geographical distribution of dominant species of R.dauricum plant communities in Northeast China and used principal component analysis(PCA)to analyze the impact of geographical and climate factors on species distribution.The results show that at the local scale,the IV of the species in each community varies widely.At the intermediate scale,species with a wide niche breadth tend to have a high value for IV.Larix gmelinii,Betula platyphylla,R.dauricum,Ledum palustre,and Vaccinium vitis-idaea had a relatively wide niche breadth and a high niche overlap,and the interspecific associations were almost all positive.Elevation and soil nutrients were the most dominant environmental factors.At the regional scale,species with a wide niche breadth tend to have a wide range of distribution,and temperature and precipitation were the most dominant environmental factors.This study suggests that the niche characteristics at three scales are both related and different.Niche characteristics at the local scale were various and labile,and niche characteristics at the intermediate and regional scales were relatively regular.These results show some degree of consistency with previous studies from an evolutionary perspective.The action mechanisms of these communities are related to differences in the dominant environmental factors.In addition,the integration of niche overlap and interspecific association determine interspecific relationships more accurately.
基金Supported by the National Natural Science Foundation of China(No.41106073)the Technology R&D Program of Fujian Provincial Department of Ocean and Fisheries(No.2012013)
文摘An index of relative importance(IRI) was employed to screen for dominant fish in the waters surrounding the Taishan Islands, China, using data from four seasonal trawl surveys undertaken between 2012 and 2013. Niche breadth and niche overlap were measured using the Feinsinger and Morisita-Horn indices, respectively, and the characteristics and seasonal variations in the niches of dominant fish were assessed via non-metric multidimensional scaling(NMDS) and cluster analysis. A total of 80 fish species, including 16 dominant species, were recorded. Only A mblychaeturichthys hexanema was dominant in all seasons. According to niche breadth values and NMDS, the 16 dominant species were grouped into the following three types:(1) wide niche breadth species, including Cynoglossus macrolepidotus, A. hexanema, and Trypauchen vagina, among others;(2) medium niche breadth species, including Setipinna taty and Johnius belangerii; and(3) narrow niche breadth species, including A trobucca nibe and Coilia mystus. Most species with a wider niche breadth were demersal fish with a lower swimming capability and even distribution. The niche breadth of migrating fish was narrower than that of settled fish. At a given spatial scale, fish with stronger swimming capabilities had a narrower niche breadth. Niche overlap, which is associated with niche specialization, ranged from 0.000 to 0.886 and had an annual mean value of 0.314. In summer and autumn, niche overlap was relatively high within species of the Sciaenidae family and within species of the Gobiidae in autumn. Dif ferences in thermophily, feeding habits, food organism abundance/distribution and predator-prey relationships af fected the niche overlap of fish in this area. Cluster analysis revealed that species with the narrowest niche breadth and lowest niche overlap values usually displayed lower aggregation and greater distribution dif ferences compared with other species.
