Environmental fluctuations are a pervasive natural phenomenon that typically favor diverse maternal investment strategies.Organisms across various evolutionary lineages have acquired the ability to enter the dormancy ...Environmental fluctuations are a pervasive natural phenomenon that typically favor diverse maternal investment strategies.Organisms across various evolutionary lineages have acquired the ability to enter the dormancy state to tolerate conditions that are unsuitable for normal life activities.In cyclical parthenogenesis,sexual reproduction is generally linked with dormancy,thereby enhancing the long-term fitness of populations through positive feedback mechanisms.This study evaluates the impact of environmental variability on offspring population dynamics through sexual reproduction in the rotifer Brachionus calyciflorus.We found that mictic females(sexual females)exposed to low-predictability environments produced resting eggs with a sporadic hatching pattern,reduced hatching rate,and smaller sizes of resting egg,embryo,and stem females,while increasing variations in fertilization among individuals to maximize population fitness.Variations in population growth could be manifested in enhanced reproductive capacity 2–3 d post-hatching,along with differences in fecundity among individuals.This suggests that dormant eggs from unstable environments may prioritize offspring survival and adjust to increased fertilization among individuals.This adaptive strategy enables rotifer populations to rapidly adjust to environmental changes,thus avoiding extinction and thriving in diverse habitats.Our systematic study enhances the understanding of how environmental stability affects long-term population fitness in cyclical parthenogens.展开更多
Nanoplastics(less than 1µm in size,NPs)have emerged as a significant pollutant in aquatic environment,posing considerable threats to freshwater biota.However,the mechanisms through which NPs modulate the predatio...Nanoplastics(less than 1µm in size,NPs)have emerged as a significant pollutant in aquatic environment,posing considerable threats to freshwater biota.However,the mechanisms through which NPs modulate the predation responses of these organisms remain poorly elucidated.We investigated the impacts of polystyrene NPs,characterized by a representative particle size(diameter:50 nm;concentration:0–8μg/L),on the anti-predation defense mechanisms of mature rotifer Brachionus calyciflorus against predator of rotifer Asplanchna brightwellii,utilizing transcriptomics to unravel the underlying molecular pathways.Results reveal that the posterolateral spine length and type of B.calyciflorus serve as robust indicators of defensive morphology,even in the presence of NPs exposure.Specifically,increasing concentrations of NPs and predator cues suppressed the defensive responses,which was associated with morphological transformations.This suppression was associated with the down-regulation of the HIF-1αsignaling pathway,implicating potentially its role in modulating fight-or-flight responses.Furthermore,we identified functional crosstalk among multiple signaling pathways,including HIF-1α,PI3K-Akt,FoxO,and mTOR,in B.calyciflorus,which may underpin the organism's responses to polystyrene NP exposure.These findings contribute to the advancement of predictive models to assess the ecological risks posed by polystyrene NPs contamination in aquatic ecosystems.展开更多
Haemaphysalis longicornis ticks,commonly found in East Asia,can transmit various pathogenic viruses,includingthe severe fever with thrombocytopenia syndrome virus(SFTSV)that has caused febrile diseases among humansin ...Haemaphysalis longicornis ticks,commonly found in East Asia,can transmit various pathogenic viruses,includingthe severe fever with thrombocytopenia syndrome virus(SFTSV)that has caused febrile diseases among humansin Hubei Province.However,understanding of the viromes of H.longicornis was limited,and the prevalence ofviruses among H.longicornis ticks in Hubei was not well clarified.This study investigates the viromes of bothengorged(fed)and free(unfed)H.longicornis ticks across three mountainous regions in Hubei Province from 2019to 2020.RNA-sequencing analysis identified viral sequences that were related to 39 reference viruses belonging tounclassified viruses and seven RNA viral families,namely Chuviridae,Nairoviridae,Orthomyxoviridae,Parvoviridae,Phenuiviridae,Rhabdoviridae,and Totiviridae.Viral abundance and diversity in these ticks were analysed,andphylogenetic characteristics of the Henan tick virus(HNTV),Dabieshan tick virus(DBSTV),Okutama tick virus(OKTV),and Jingmen tick virus(JMTV)were elucidated based on their full genomic sequences.Prevalenceanalysis demonstrated that DBSTV was the most common virus found in individual H.longicornis ticks(12.59%),followed by HNTV(0.35%),whereas JMTV and OKTV were not detected.These results improve our understanding of H.longicornis tick viromes in central China and highlight the role of tick feeding status and geographyin shaping the viral community.The findings of new viral strains and their potential impact on public health raisethe need to strengthen surveillance efforts for comprehensively assessing their spillover potentials.展开更多
基金Supported by the National Natural Science Foundation of China(No.32071528)。
文摘Environmental fluctuations are a pervasive natural phenomenon that typically favor diverse maternal investment strategies.Organisms across various evolutionary lineages have acquired the ability to enter the dormancy state to tolerate conditions that are unsuitable for normal life activities.In cyclical parthenogenesis,sexual reproduction is generally linked with dormancy,thereby enhancing the long-term fitness of populations through positive feedback mechanisms.This study evaluates the impact of environmental variability on offspring population dynamics through sexual reproduction in the rotifer Brachionus calyciflorus.We found that mictic females(sexual females)exposed to low-predictability environments produced resting eggs with a sporadic hatching pattern,reduced hatching rate,and smaller sizes of resting egg,embryo,and stem females,while increasing variations in fertilization among individuals to maximize population fitness.Variations in population growth could be manifested in enhanced reproductive capacity 2–3 d post-hatching,along with differences in fecundity among individuals.This suggests that dormant eggs from unstable environments may prioritize offspring survival and adjust to increased fertilization among individuals.This adaptive strategy enables rotifer populations to rapidly adjust to environmental changes,thus avoiding extinction and thriving in diverse habitats.Our systematic study enhances the understanding of how environmental stability affects long-term population fitness in cyclical parthenogens.
基金Supported by the earmarked fund for China Agriculture Research System(No.CARS-50)the Doctors Research Funding of Henan Normal University(No.20230246)。
文摘Nanoplastics(less than 1µm in size,NPs)have emerged as a significant pollutant in aquatic environment,posing considerable threats to freshwater biota.However,the mechanisms through which NPs modulate the predation responses of these organisms remain poorly elucidated.We investigated the impacts of polystyrene NPs,characterized by a representative particle size(diameter:50 nm;concentration:0–8μg/L),on the anti-predation defense mechanisms of mature rotifer Brachionus calyciflorus against predator of rotifer Asplanchna brightwellii,utilizing transcriptomics to unravel the underlying molecular pathways.Results reveal that the posterolateral spine length and type of B.calyciflorus serve as robust indicators of defensive morphology,even in the presence of NPs exposure.Specifically,increasing concentrations of NPs and predator cues suppressed the defensive responses,which was associated with morphological transformations.This suppression was associated with the down-regulation of the HIF-1αsignaling pathway,implicating potentially its role in modulating fight-or-flight responses.Furthermore,we identified functional crosstalk among multiple signaling pathways,including HIF-1α,PI3K-Akt,FoxO,and mTOR,in B.calyciflorus,which may underpin the organism's responses to polystyrene NP exposure.These findings contribute to the advancement of predictive models to assess the ecological risks posed by polystyrene NPs contamination in aquatic ecosystems.
基金supported by the National Natural Science Foundation of China(grant number:U21A20180)the National Key R&D Program of China(2021YFC2300900,2022YFC2305100)+2 种基金the Key Deployment Projects of the Chinese Academy of Sciences(KJZD-SW-L11)the Youth Project of the Wuhan Institute of Virology,Chinese Academy of Sciences(2023QNTJ-03)the National Basic Science Data Sharing Service Platform(NBSDC-DB-13).
文摘Haemaphysalis longicornis ticks,commonly found in East Asia,can transmit various pathogenic viruses,includingthe severe fever with thrombocytopenia syndrome virus(SFTSV)that has caused febrile diseases among humansin Hubei Province.However,understanding of the viromes of H.longicornis was limited,and the prevalence ofviruses among H.longicornis ticks in Hubei was not well clarified.This study investigates the viromes of bothengorged(fed)and free(unfed)H.longicornis ticks across three mountainous regions in Hubei Province from 2019to 2020.RNA-sequencing analysis identified viral sequences that were related to 39 reference viruses belonging tounclassified viruses and seven RNA viral families,namely Chuviridae,Nairoviridae,Orthomyxoviridae,Parvoviridae,Phenuiviridae,Rhabdoviridae,and Totiviridae.Viral abundance and diversity in these ticks were analysed,andphylogenetic characteristics of the Henan tick virus(HNTV),Dabieshan tick virus(DBSTV),Okutama tick virus(OKTV),and Jingmen tick virus(JMTV)were elucidated based on their full genomic sequences.Prevalenceanalysis demonstrated that DBSTV was the most common virus found in individual H.longicornis ticks(12.59%),followed by HNTV(0.35%),whereas JMTV and OKTV were not detected.These results improve our understanding of H.longicornis tick viromes in central China and highlight the role of tick feeding status and geographyin shaping the viral community.The findings of new viral strains and their potential impact on public health raisethe need to strengthen surveillance efforts for comprehensively assessing their spillover potentials.
