Objective:To investigate the effect of a water-soluble nacre extract derived from Pinctada fucata on skeletal muscle aging.Methods:Naturally aged C57BL/6J mice received nacre extract mixed in chow for 12 weeks.Forelim...Objective:To investigate the effect of a water-soluble nacre extract derived from Pinctada fucata on skeletal muscle aging.Methods:Naturally aged C57BL/6J mice received nacre extract mixed in chow for 12 weeks.Forelimb grip strength,hanging performance,and locomotor activity were assessed.Skeletal muscle remodeling and signaling were evaluated by histology and immunostaining for fibrosis,contractile-marker features,senescence-and DNA damage-associated markers,inflammatory signaling,and mitochondrial proteins.Oxidative status was assessed by determining antioxidant capacity,lipid peroxidation,and oxidative DNA damage.Transcriptomic profiling was also performed,and selected targets were validated by quantitative RT-PCR and immunostaining.In addition,differentiated C2C12 myotubes were exposed to doxorubicin and treated with nacre extract;senescence-associated β-galactosidase,DNA damage signaling,and cell viability were measured.Results:Nacre extract increased forelimb grip strength and showed a positive trend in hanging performance without altering spontaneous locomotion.It also reduced collagen deposition,preserved contractile-marker immunoreactivity,attenuated senescence-and inflammation-associated signals,and increased mitochondrial protein immunoreactivity.Oxidative DNA damage was notably reduced by nacre extract.Transcriptomics indicated modulation of stress/redox programs and increased neurotrophic tyrosine kinase receptor type 2 expression,which were supported by tissue-level validation.In C2C12 myotubes,nacre extract suppressed doxorubicin-induced senescence-associated phenotypes without loss of cell viability.Conclusions:Water-soluble nacre extract mitigates skeletal muscle aging through coordinated modulation of oxidative stress,inflammation,mitochondrial features,and cellular senescence.展开更多
Microplastics(MPs),particularly polyvinyl chloride microplastics(PVC MPs)have become a notable environmental pollutant that affect various marine organisms such as Pinctada fucata martensii.As filter feeders,these biv...Microplastics(MPs),particularly polyvinyl chloride microplastics(PVC MPs)have become a notable environmental pollutant that affect various marine organisms such as Pinctada fucata martensii.As filter feeders,these bivalves consume significant volumes of water containing MPs,leading to contact with and ingestion of MPs.Moreover,given the ecological and economic importance of P.f.martensii in artificial pearl production,investigating the effects of PVC MPs exposure is crucial.This study aimed to investigate the effects of PVC MPs exposure on nucleus retention,pearl formation,oxidative stress by examining superoxide dismutase(SOD)activity,catalase(CAT)activity,lipid peroxidation(LPO),and total antioxidant capacity(TAOC)of P.f.martensii,while also exploring transcriptomic changes at different concentrations and exposure time points,including a recovery period.The pearl oysters were exposed to PVC MPs at concentrations of 1-,2.5-,and 5-mg PVC MPs/L for 10 d followed by 6 d of recovery.After 1-,4-,10-d of exposure,and additional 6 d of recovery,samples were taken and analyzed.Findings revealed that only prolonged exposure(10 d)to PVC MPs affected SOD activity,while CAT activity,LPO,and TAOC remained unaffected throughout the experiment.Notably,SOD activity was restored during the 6-d recovery phase.Transcriptome analysis highlighted significant gene alterations linked to various pathways,affecting cellular processes,environmental information processing,genetic information processing,metabolism,and organismal systems,with an increase in pathway-related genes during recovery,implying a potential role of PVC MPs as gene inhibitors.This study provided insights into the effects of PVC MPs on P.f.martensii,shedding light on pearl retention,oxidative systems,and molecular pathways influenced by PVC MPs.Additionally,it contributed novel information on potential MPs exposure biomarkers,particularly relevant to marine organisms like P.f.martensii.展开更多
The silver-lipped pearl oyster(Pinctada maxima)is the largest and most commercially valuable pearl-producing oyster,renowned for its ability to generate large,lustrous pearls.This species is a sequential hermaphrodite...The silver-lipped pearl oyster(Pinctada maxima)is the largest and most commercially valuable pearl-producing oyster,renowned for its ability to generate large,lustrous pearls.This species is a sequential hermaphrodite,with pearl production displaying notable sexual dimorphism.Consequently,understanding the molecular mechanisms governing sex determination and differentiation is crucial for advancing breeding strategies in the pearl oyster industry.To elucidate these mechanisms,this study conducted integrative transcriptomic analyses of P.maxima gonadal tissues using isoform sequencing(Isoseq)and RNA sequencing(RNA-seq).Comparative analysis of ovarian and testicular tissues identified 2768 differentially expressed genes(DEGs).Gene coexpression network analysis delineated four key modules,including three sex-specific modules and one shared module.Key genes implicated in sex determination and maintenance were identified,including FOXL2,NANOS1,andβ-catenin,important for ovarian maintenance,and DMRT,SOX30,FEM1,and FOXJ1,crucial for testicular maintenance.These genes,widely studied in other taxa,were confirmed as hub genes in the sex-related modules of P.maxima.Interestingly,genes within the shared module were significantly enriched in the spliceosome pathway.Alternative splicing analysis highlighted its extensive role in gonadal tissues,with more pronounced activity observed in the testis compared to the ovary.Nearly half(47.83%,375)of the identified genes undergoing differential alternative splicing(DASGs)also exhibited differential transcript usage(DTUGs),while only 17%of DTUGs overlapped with DEGs.Genes associated with sex differentiation,such as DMRT,β-catenin,and U2AF2,displayed sex-specific and/or sex-biased isoforms.These findings offer novel insights into the molecular basis of sex differentiation in P.maxima,which could inform the development of targeted breeding strategies aimed at sex control,thereby enhancing pearl quality and yield in aquaculture.This study offers a robust molecular foundation for advancing breeding programs and optimizing production in the pearl oyster industry.展开更多
In May of 2007,the second generation selected （SS） and control （SC） groups of pearl oyster Pinctada martensii were established by selecting 10% breeders with the largest and mean shell length,respectively,from the...In May of 2007,the second generation selected （SS） and control （SC） groups of pearl oyster Pinctada martensii were established by selecting 10% breeders with the largest and mean shell length,respectively,from the first generation selected group.Growth performance of the SS and SC groups were compared on the basis of measurement data at Days 8,18,60,95,195 and 365.On Day 365,100 individuals （60.0–75.0 mm at shell length） were sampled from each group and then subjected to the experiment where physiological parameters such as filtrate rate,oxygen consumption and ammonia excretion were measured at 15,20,25 and 30°C.The results show that the SS group had significantly larger mean shell length and shell height than the SC group at Days 8,18,60,95,195 and 365 （P 0.05）.The genetic gains at different ages varied from 6.0% to 17.0% for shell length and 5.7% to 14.6% for shell height,respectively.At 15,20,25 and 30 ° C,the SS groups had significantly larger filtrate rate than the SC group （P 0.05）.At 15 and 25 °C,the differences in oxygen consumption rate between the SS and SC groups were not significant （P 0.05）.At 20 and 30 °C,however,the oxygen consumption rate of the SS group was significantly larger than the SC group （P 0.05）.At 15,20,25 and 30 °C,there were no significant differences in ammonia excretion rate between the SS and SC groups （P 0.05）.The present results indicate that there existed considerable genetic variability in the base population and a further selection could be likely fruitful.Mass selection for faster growth might produce animals that had higher intake of metabolizable energy by virtue of faster filtrating behavior.展开更多
The mechanisms of sex determination and sex differentiation in the pearl oyster P inctada fucata are currently poorly understood. We therefore investigated the roles of orthologs of the D mrt gene family, key players ...The mechanisms of sex determination and sex differentiation in the pearl oyster P inctada fucata are currently poorly understood. We therefore investigated the roles of orthologs of the D mrt gene family, key players in male gonad differentiation in mammals, in P. fucata sex diff erentiation and sexual development. Pf-Dmrt4 exhibits features typical of the D mrt family, and displays significant homologies to the DMRT4 cluster. Pf-Dmrt4 mRNA expression in the gonads during a gametogenic cycle, measured by quantitative polymerase chain reaction, was maximal in mature individuals. P f-Dmrt4 expression, demonstrated by in situ hybridization, was localized in the spermatozoa, spermatids, oocytes and vitellogenic oocytes. Knockdown of Pf-Dmrt4 with double-stranded RNA resulted in decreased mRNA expression levels. And Pf-Dmrt4-dsRNA-injected groups showed spawning-stage male gonads, with ruptured follicles and released spermatozoa. Our results enhance the understanding of sex determination and differentiation in P. fucata and suggest that Pf-Dmrt4 could be involved in male gonadal development, and maintenance of male gonadal function.展开更多
The present study investigated the removal of inorganic arsenic from Pinctada martensii enzymatic hydrolysate through unmodified resin （D296） and Zr（IV）-loaded chelating resin （Zr-D401）. By loading Zr to macropo...The present study investigated the removal of inorganic arsenic from Pinctada martensii enzymatic hydrolysate through unmodified resin （D296） and Zr（IV）-loaded chelating resin （Zr-D401）. By loading Zr to macroporous chelating resin D401, the as exchange adsorption active sites are generated. This transforms D401 from a material that does not have the arsenic adsorption capacity into a material that has excellent arsenic exchange adsorption capacity. The static adsorption experiments were conducted to investigate the optimal removal condition for D296 and Zr-D401. The experimental results show that： the optimum condition for D296 is that T= 25℃, pH= 5, resin additive amount= 1 g （50 mL）-1, and contact time = 10 h, the corresponding arsenic removal rate being 65.7%, and protein loss being 2.33%; the optimum condition for Zr-D401 is that T=25 ℃, pH = 8, resin additive amount= 1 g （50 mL）-1, and contact time=10 h, the corresponding arsenic removal rate being 70.3%, and protein loss being 4.65%. These results show that both of the two resins are effective in arsenic removal for preserving useful substance. Our research provides scientific evidence and advances in the processing technology for heavy metal removal in shellfish.展开更多
The death which occurred in juvenile population was a severe problem in the course ofPinctada maxima artificial culture. With the methods of field investigation, histological study and statistic analyses, the epidemio...The death which occurred in juvenile population was a severe problem in the course ofPinctada maxima artificial culture. With the methods of field investigation, histological study and statistic analyses, the epidemiological study was carried out on the disease and death in juvenile populations of Pinctada maxima in the Xinying Pearl Oyster Mariculture Farm of Lingao County (for the A, B and C batches of cultured juveniles hanged in the sea) and the Xincun Pearl Oyster Mariculture Farm of Lingshui County (for the D batch of cultured juvenile hanged in the pond), Hainan Province from November 1993 to April 1995.The results show that the deaths which occurred in juvenile populations of Pinctada maxima presented an outbreak pattern. The peak of mortality rates, in general, occurred in 4-to 6-month old pearl oyster juveniles, and the mortality rates gradully declined with the extention of pearl oyster age after cul-turing 8 months. The correlation between the mortality rates of juvenile populations and mean body lengths of juvenile populations show that the mortality rate become higher under 4 cm of mean body lengths of juvenile population and become obvious declined over 5 cm of mean body lengths. The peak of mortality rate occurred in 1-3 cm of mean body lengths. The results of histological observation showed that rickettsia-like organism inclusions were common, histological widespread infective agent among every batches (A, B, C and D) of cultured juvenile populations. The mean severity indices (SI) of rickettsia-like organism (RLO) infection were positively correlated with mortality rates of juvenile populations. After or within every peaks of RLO infection were all accompanied with the peaks of mortality rates of host populations and the mortality rates declined with decreased RLO infection. So the evidences of histological observation and epidemiology in this study indicated that rickettsia-like organism (RLO) may be as an important pathogenic organism of disease and death of cultured Pinctada maxima. In addition, a few ciliates were discovered only in part of batch A of cultured juvenile population. The mortality rates in juvenile populations were not correlated with the weekly mean temperature and salinity of sea water.展开更多
文摘Objective:To investigate the effect of a water-soluble nacre extract derived from Pinctada fucata on skeletal muscle aging.Methods:Naturally aged C57BL/6J mice received nacre extract mixed in chow for 12 weeks.Forelimb grip strength,hanging performance,and locomotor activity were assessed.Skeletal muscle remodeling and signaling were evaluated by histology and immunostaining for fibrosis,contractile-marker features,senescence-and DNA damage-associated markers,inflammatory signaling,and mitochondrial proteins.Oxidative status was assessed by determining antioxidant capacity,lipid peroxidation,and oxidative DNA damage.Transcriptomic profiling was also performed,and selected targets were validated by quantitative RT-PCR and immunostaining.In addition,differentiated C2C12 myotubes were exposed to doxorubicin and treated with nacre extract;senescence-associated β-galactosidase,DNA damage signaling,and cell viability were measured.Results:Nacre extract increased forelimb grip strength and showed a positive trend in hanging performance without altering spontaneous locomotion.It also reduced collagen deposition,preserved contractile-marker immunoreactivity,attenuated senescence-and inflammation-associated signals,and increased mitochondrial protein immunoreactivity.Oxidative DNA damage was notably reduced by nacre extract.Transcriptomics indicated modulation of stress/redox programs and increased neurotrophic tyrosine kinase receptor type 2 expression,which were supported by tissue-level validation.In C2C12 myotubes,nacre extract suppressed doxorubicin-induced senescence-associated phenotypes without loss of cell viability.Conclusions:Water-soluble nacre extract mitigates skeletal muscle aging through coordinated modulation of oxidative stress,inflammation,mitochondrial features,and cellular senescence.
基金Supported by the Science and Technology Program of Guangdong Province(No.2022A1515010030)the National Natural Science Foundation of China(No.32102817)+3 种基金the Department of Education of Guangdong Province(Nos.2020ZDZX1045,2021KCXTD026)the earmarked fund for CARS-49,Students Innovation and Entrepreneurship Training Program(No.CXXL2022015)the Technology Program of Guangdong Zhanjiang(No.2022A01010)the Hengli Biosciences Excellence Project of Guangdong Ocean University(No.B23335-4)。
文摘Microplastics(MPs),particularly polyvinyl chloride microplastics(PVC MPs)have become a notable environmental pollutant that affect various marine organisms such as Pinctada fucata martensii.As filter feeders,these bivalves consume significant volumes of water containing MPs,leading to contact with and ingestion of MPs.Moreover,given the ecological and economic importance of P.f.martensii in artificial pearl production,investigating the effects of PVC MPs exposure is crucial.This study aimed to investigate the effects of PVC MPs exposure on nucleus retention,pearl formation,oxidative stress by examining superoxide dismutase(SOD)activity,catalase(CAT)activity,lipid peroxidation(LPO),and total antioxidant capacity(TAOC)of P.f.martensii,while also exploring transcriptomic changes at different concentrations and exposure time points,including a recovery period.The pearl oysters were exposed to PVC MPs at concentrations of 1-,2.5-,and 5-mg PVC MPs/L for 10 d followed by 6 d of recovery.After 1-,4-,10-d of exposure,and additional 6 d of recovery,samples were taken and analyzed.Findings revealed that only prolonged exposure(10 d)to PVC MPs affected SOD activity,while CAT activity,LPO,and TAOC remained unaffected throughout the experiment.Notably,SOD activity was restored during the 6-d recovery phase.Transcriptome analysis highlighted significant gene alterations linked to various pathways,affecting cellular processes,environmental information processing,genetic information processing,metabolism,and organismal systems,with an increase in pathway-related genes during recovery,implying a potential role of PVC MPs as gene inhibitors.This study provided insights into the effects of PVC MPs on P.f.martensii,shedding light on pearl retention,oxidative systems,and molecular pathways influenced by PVC MPs.Additionally,it contributed novel information on potential MPs exposure biomarkers,particularly relevant to marine organisms like P.f.martensii.
基金supported by the Hainan Province Science and Technology Talent Innovation Project(KJRC2023A02)Project of Sanya Yazhouwan Science and Technology City Management Foundation(SKJC-KJ-2019KY01)Sanya Science and Technology Special Fund(2022KJCX91)。
文摘The silver-lipped pearl oyster(Pinctada maxima)is the largest and most commercially valuable pearl-producing oyster,renowned for its ability to generate large,lustrous pearls.This species is a sequential hermaphrodite,with pearl production displaying notable sexual dimorphism.Consequently,understanding the molecular mechanisms governing sex determination and differentiation is crucial for advancing breeding strategies in the pearl oyster industry.To elucidate these mechanisms,this study conducted integrative transcriptomic analyses of P.maxima gonadal tissues using isoform sequencing(Isoseq)and RNA sequencing(RNA-seq).Comparative analysis of ovarian and testicular tissues identified 2768 differentially expressed genes(DEGs).Gene coexpression network analysis delineated four key modules,including three sex-specific modules and one shared module.Key genes implicated in sex determination and maintenance were identified,including FOXL2,NANOS1,andβ-catenin,important for ovarian maintenance,and DMRT,SOX30,FEM1,and FOXJ1,crucial for testicular maintenance.These genes,widely studied in other taxa,were confirmed as hub genes in the sex-related modules of P.maxima.Interestingly,genes within the shared module were significantly enriched in the spliceosome pathway.Alternative splicing analysis highlighted its extensive role in gonadal tissues,with more pronounced activity observed in the testis compared to the ovary.Nearly half(47.83%,375)of the identified genes undergoing differential alternative splicing(DASGs)also exhibited differential transcript usage(DTUGs),while only 17%of DTUGs overlapped with DEGs.Genes associated with sex differentiation,such as DMRT,β-catenin,and U2AF2,displayed sex-specific and/or sex-biased isoforms.These findings offer novel insights into the molecular basis of sex differentiation in P.maxima,which could inform the development of targeted breeding strategies aimed at sex control,thereby enhancing pearl quality and yield in aquaculture.This study offers a robust molecular foundation for advancing breeding programs and optimizing production in the pearl oyster industry.
基金The National Key Technology R&D Program in the 11th Five Year Plan of China under contract No. 2007BAD29B01-2National Department Public Benefit Research Foundation under contract No. nyhyzx 07-048Guangdong Marine and Fishery Bureau under contract Nos A200708C01, A200908A02 and A200908A05
文摘In May of 2007,the second generation selected （SS） and control （SC） groups of pearl oyster Pinctada martensii were established by selecting 10% breeders with the largest and mean shell length,respectively,from the first generation selected group.Growth performance of the SS and SC groups were compared on the basis of measurement data at Days 8,18,60,95,195 and 365.On Day 365,100 individuals （60.0–75.0 mm at shell length） were sampled from each group and then subjected to the experiment where physiological parameters such as filtrate rate,oxygen consumption and ammonia excretion were measured at 15,20,25 and 30°C.The results show that the SS group had significantly larger mean shell length and shell height than the SC group at Days 8,18,60,95,195 and 365 （P 0.05）.The genetic gains at different ages varied from 6.0% to 17.0% for shell length and 5.7% to 14.6% for shell height,respectively.At 15,20,25 and 30 ° C,the SS groups had significantly larger filtrate rate than the SC group （P 0.05）.At 15 and 25 °C,the differences in oxygen consumption rate between the SS and SC groups were not significant （P 0.05）.At 20 and 30 °C,however,the oxygen consumption rate of the SS group was significantly larger than the SC group （P 0.05）.At 15,20,25 and 30 °C,there were no significant differences in ammonia excretion rate between the SS and SC groups （P 0.05）.The present results indicate that there existed considerable genetic variability in the base population and a further selection could be likely fruitful.Mass selection for faster growth might produce animals that had higher intake of metabolizable energy by virtue of faster filtrating behavior.
基金Supported by the Earmarked Fund for Modern Agro-industry Technology Research System(No.CARS-49)the Marine Fishery Science and Technology Development Project of Guangdong Province,China(Nos.Z2014012,Z2015014)the Science and Technology Planning Project of Guangdong Province,China(No.2014B030301064)
文摘The mechanisms of sex determination and sex differentiation in the pearl oyster P inctada fucata are currently poorly understood. We therefore investigated the roles of orthologs of the D mrt gene family, key players in male gonad differentiation in mammals, in P. fucata sex diff erentiation and sexual development. Pf-Dmrt4 exhibits features typical of the D mrt family, and displays significant homologies to the DMRT4 cluster. Pf-Dmrt4 mRNA expression in the gonads during a gametogenic cycle, measured by quantitative polymerase chain reaction, was maximal in mature individuals. P f-Dmrt4 expression, demonstrated by in situ hybridization, was localized in the spermatozoa, spermatids, oocytes and vitellogenic oocytes. Knockdown of Pf-Dmrt4 with double-stranded RNA resulted in decreased mRNA expression levels. And Pf-Dmrt4-dsRNA-injected groups showed spawning-stage male gonads, with ruptured follicles and released spermatozoa. Our results enhance the understanding of sex determination and differentiation in P. fucata and suggest that Pf-Dmrt4 could be involved in male gonadal development, and maintenance of male gonadal function.
基金supported by National Key Technologies R&D Program of China(2008 BAD94B08)
文摘The present study investigated the removal of inorganic arsenic from Pinctada martensii enzymatic hydrolysate through unmodified resin （D296） and Zr（IV）-loaded chelating resin （Zr-D401）. By loading Zr to macroporous chelating resin D401, the as exchange adsorption active sites are generated. This transforms D401 from a material that does not have the arsenic adsorption capacity into a material that has excellent arsenic exchange adsorption capacity. The static adsorption experiments were conducted to investigate the optimal removal condition for D296 and Zr-D401. The experimental results show that： the optimum condition for D296 is that T= 25℃, pH= 5, resin additive amount= 1 g （50 mL）-1, and contact time = 10 h, the corresponding arsenic removal rate being 65.7%, and protein loss being 2.33%; the optimum condition for Zr-D401 is that T=25 ℃, pH = 8, resin additive amount= 1 g （50 mL）-1, and contact time=10 h, the corresponding arsenic removal rate being 70.3%, and protein loss being 4.65%. These results show that both of the two resins are effective in arsenic removal for preserving useful substance. Our research provides scientific evidence and advances in the processing technology for heavy metal removal in shellfish.
基金Major State Basic Research Development Program of China under contract No. G1999012001Key Science Foundation of the Chinese Academy of Sciences contract KS85-121.
文摘The death which occurred in juvenile population was a severe problem in the course ofPinctada maxima artificial culture. With the methods of field investigation, histological study and statistic analyses, the epidemiological study was carried out on the disease and death in juvenile populations of Pinctada maxima in the Xinying Pearl Oyster Mariculture Farm of Lingao County (for the A, B and C batches of cultured juveniles hanged in the sea) and the Xincun Pearl Oyster Mariculture Farm of Lingshui County (for the D batch of cultured juvenile hanged in the pond), Hainan Province from November 1993 to April 1995.The results show that the deaths which occurred in juvenile populations of Pinctada maxima presented an outbreak pattern. The peak of mortality rates, in general, occurred in 4-to 6-month old pearl oyster juveniles, and the mortality rates gradully declined with the extention of pearl oyster age after cul-turing 8 months. The correlation between the mortality rates of juvenile populations and mean body lengths of juvenile populations show that the mortality rate become higher under 4 cm of mean body lengths of juvenile population and become obvious declined over 5 cm of mean body lengths. The peak of mortality rate occurred in 1-3 cm of mean body lengths. The results of histological observation showed that rickettsia-like organism inclusions were common, histological widespread infective agent among every batches (A, B, C and D) of cultured juvenile populations. The mean severity indices (SI) of rickettsia-like organism (RLO) infection were positively correlated with mortality rates of juvenile populations. After or within every peaks of RLO infection were all accompanied with the peaks of mortality rates of host populations and the mortality rates declined with decreased RLO infection. So the evidences of histological observation and epidemiology in this study indicated that rickettsia-like organism (RLO) may be as an important pathogenic organism of disease and death of cultured Pinctada maxima. In addition, a few ciliates were discovered only in part of batch A of cultured juvenile population. The mortality rates in juvenile populations were not correlated with the weekly mean temperature and salinity of sea water.
