Intraspecific conflict induced by the innate aggressiveness is one of the main reasons for the extremely low survival rate in mud crab Scylla paramamosain aquaculture,which have impeded the sustainable culture of the ...Intraspecific conflict induced by the innate aggressiveness is one of the main reasons for the extremely low survival rate in mud crab Scylla paramamosain aquaculture,which have impeded the sustainable culture of the species.In this study,we first classified and quantified the aggressive behavior,and established a crab aggressive behavior model,laying the foundation for subsequent research on evaluating combat intensity.The contents of 5-hydroxytryptamine(5-HT),dopamine(DA),and cAMP in the hemolymph of the mud crabs before and after fighting were measured by high-performance liquid chromatography-mass spectrometry(HPLC-MS),and the mud crabs exhibited a significant increase of 5-HT(P<0.05),while the DA and cAMP decreased significantly(P<0.05).In addition,we applied EthoVision to examine the changes of the crab behavior after DA administration.After 0.5 h of injection,the movement speed,distance,duration of aggressive behavior,and intensity of aggression in the high concentration DA group were significantly higher than those in the saline injection group and the untreated control group(P<0.05).The results of real-time quantitative polymerase chain reaction(qRT PCR)analysis showed that the expression of DA 1 in the thoracic ganglia of the mud crabs was significantly down-regulated in the DA injection group,and the aggressive behavior was weakened.Conversely,DA1 expression was up-regulated when aggressive behavior was strengthened.Besides,there were significant differences in the expression levels of receptor expression genes including 5-HT1,5-HT2,and crustacean hyperglycemic hormone(CHH)in different tissues,indicating that the alteration of aggressive behavior of the mud crab after injection with different concentrations of DA could be regulated by changes in the expression levels of corresponding receptor genes.Our results contribute to a deeper analysis of the aggressive behavior mechanism of the mud crabs and provide a theoretical basis for reducing fighting-related mortalities in aquaculture.展开更多
The farming of Scylla paramamosain with specific flavors has a higher commercial value,and the flavors are related to the integrated farming environment and non-volatile flavor substances,while the survival environmen...The farming of Scylla paramamosain with specific flavors has a higher commercial value,and the flavors are related to the integrated farming environment and non-volatile flavor substances,while the survival environment is one of the important ways to source gut microorganisms in the organism.In this study,the levels of dominant taxa in the gut flora of S.paramamosain from Mong Cai,Vietnam(VN),Taishan City,Guangdong Province(TS)of China,and Ninghai County,Ningbo City(NB)Zhejiang Province of China converged with those of S.paramamosain from Sanmen County,Ningbo City(CK 1,CK 2,and CK 3)at 28 d of domestication.The top 15 genera with the highest abundance of VN,TS,and NB gut flora were the same as CK 1,CK 2,and CK 3,but with different percentages,and gradually converged to CK 1,CK 2,and CK 3,respectively,at 28 d of domestication.Correlation between intestinal flora and non-volatile flavor substances in the hepatopancreas at the percentage level of relative abundance of bacterial genera found that above 28 d of domestication,Muribaculaceae,Psychrilyobacter,Clostridia_vadinBB 60_group,Halarcobacter Carboxylicivirga,Sediminispirochaeta may be the most important genera affecting flavor amino acids of VN.Sediminispirochaeta,Carboxylicivirga,Halarcobacter,Photobacterium,ZOR 0006,Psychrilyobacter,and Pseudomonas may be the most important genera affecting flavor amino acids of NB.Sediminispirochaeta,Carboxylicivirga,Halarcobacter,Photobacterium,ZOR 0006,Vibrio,and Sphingomonas may be the most important genera affecting flavor amino acids of TS.These results show that the intestinal flora structure of crabs from different areas were domesticated in the same area for at least 28 d before they converged to that of the domesticated crab,and the most important genera affecting the flavor amino acids of TS,VN,and NB were also identified.The results of this study provide a reference and basis for the technique of directional cultivation of the flavor quality of the crab.展开更多
The identification and localization of vertebrate follicle stimulating hormone （FSH） and luteinizing hormone （LH） in crustaceans may further elucidate the regulation mechanisms in arthropod repro-duction. Using im...The identification and localization of vertebrate follicle stimulating hormone （FSH） and luteinizing hormone （LH） in crustaceans may further elucidate the regulation mechanisms in arthropod repro-duction. Using immunocytochemical staining techniques, this study has localized vertebrate FSH-like and LH-like substances in neurons in the subesophageal and thoracic ganglia from the thoracic ganglion mass （TGM） of Scylla paramamosain （Crustacea： Decapoda： Brachyura）. Enzyme-linked immunosorbent assay （ELISA） has shown that the concentrations of both FSH-and LH-like sub-stances increased markedly in the TGM during the vitellogenic stage compared with that in the previtellogenic stage. These results indicate that substances resembling the vertebrate FSH and LH are present in S. paramamosain, and they may be involved in the development of the ovary as well as in ovulation.展开更多
Innexin proteins are a class of transmembrane proteins existing in invertebrates and they have diverse biological functions. The innexin protein Sp-inx2 has been demonstrated to play roles in immune response and promo...Innexin proteins are a class of transmembrane proteins existing in invertebrates and they have diverse biological functions. The innexin protein Sp-inx2 has been demonstrated to play roles in immune response and promotion of cell apoptosis in the mud crab Scylla paramamosain . One novel innexin gene, named as Sp-inx3 was characterized from S. paramamosin in this study, with an open reading frame of 1 101 bp encoding 367 amino acid residues. Multiple sequence alignment revealed that the Sp-inx3 is highly homologous with innexin3 of Cancer boredis and Homorus americanus . Quantitative real-time PCR (qPCR) and the western blotting results revealed that Sp-inx3 gene was expressed predominantly in the eyestalk, brain, and thoracic ganglion mass in both female and male crabs. The immunohistochemistry assay (IHC) also showed the widespread and intense immunoreactivity of Sp-inx3 in the brain and thoracic ganglion mass. Sp-inx3 mRNA transcription profi les exhibited signifi cantly higher expression from the embryo1 to embryo4 period and low level of expression at the prehatching period and zoea I larva period of S . paramamosain . These results indicate that the Sp-inx3 may play an important role in the nervous system and early embryonic development of S . paramamosain.展开更多
This study investigated the effects of long-term low-salinity on the growth performance,proximate composition,amino acid and fatty acid profiles of Scylla paramamosain.The salinity of the low-salinity-culture group(LC...This study investigated the effects of long-term low-salinity on the growth performance,proximate composition,amino acid and fatty acid profiles of Scylla paramamosain.The salinity of the low-salinity-culture group(LC)and maintained-salinity-cul-ture group(MC)were set at 5 and 25 respectively.After rearing for 30 d,the survival rate(SR)of the LC group was significantly lower,whereas the average daily molting frequency(ADMF)was significantly higher than those in MC group(P<0.05).There were no significant difference for weight gain rate(WGR)and specific growth rate(SGR)between the two groups.The moisture content of the LC group was slightly higher than the MC group without significant difference.The contents of ash,crude lipid and crude pro-tein in the LC group were lower than those in the MC group,but no significant differences were found except for ash content.A total of 17 free amino acids and 23 fatty acids were identified from the muscle of S.paramamosain.The total amino acids(TAA),essen-tial amino acids(EAA)and essential amino acid index(EAAI)had no significant difference between the two groups.The crabs from LC group had a significantly higher HUFA,including EPA,DHA,ARA.The percentage of n-3 PUFA and the ratio of n-3/n-6 PUFA were significantly higher in the LC group.These results indicated that S.paramamosain rearing at low salinity had significantly de-creased SR;however,the low-salinity environment significantly promoted the accumulation of unsaturated fatty acids(UFAs),espe-cially the n-3 PUFA,which might be related to the osmoregulation mechanism.展开更多
The doublesex and mab-3 related transcription factor(DMRT)gene family is conserved from invertebrates to humans.The functions of DMRT are mainly involved in sex development and the formation of many tissues and organs...The doublesex and mab-3 related transcription factor(DMRT)gene family is conserved from invertebrates to humans.The functions of DMRT are mainly involved in sex development and the formation of many tissues and organs.In this study,a DM(Doublesex/Mab-3-domain gene was identified in the mud crab Scylla paramamosain,and was named SpDMRT99B because of its many similarities to arthropod DMRT99B and phylogenetically close relationship with arthropod DMRT99B.The cDNA of SpDMRT99B gene is 1249 bp in length,encoding 224 amino acids.From 254 bp to 928 bp there is a conserved DM domain.No transmembrane domain was identified.Through multiple amino acid alignment and phylogenetic tree analysis,the closest gene to SpDMRT99B is Eriocheir sinensis DMRT99B,followed by Macrobrachium rosenbergii and Drosophila melanogaster DMRT99B.The expressions of the gene were characterized in different tissues of female and male crabs during early development period of crab individuals,as well as in different development periods of gonads.The results showed that SpDMRT99B gene is significantly highly expressed in testis than in ovary and other tissues.The expression level of SpDMRT99B in testis at different stages is significantly higher than that in ovary,and it is particularly highly expressed in immature testis.In early developmental stages of larvae,the expressions of SpDMRT99B remain at a low level and reach a peak at zoea stage I when the body segments shape up.It is speculated that SpDMRT99B gene might be involved in the gonadal development process and somitogenesis of S.paramamosain.展开更多
As an important pattern recognition receptor(PRR)in the innate immune system,C-type lectin plays an important role in the innate immune process of invertebrates.Two C-type lectins Sp CTL-C and Sp CTL-D were characteri...As an important pattern recognition receptor(PRR)in the innate immune system,C-type lectin plays an important role in the innate immune process of invertebrates.Two C-type lectins Sp CTL-C and Sp CTL-D were characterized from mud crab(Scylla paramamosain).The predicted Sp CTL-C and Sp CTL-D proteins both contain a single carbohydrate-recognition domain(CRD)with key motif Gln-Pro-Ala(QPA)and Met-Pro-Ala(MPA),respectively.Sp CTL-C and Sp CTL-D transcripts distributed in all examined tissues,and the expression level was the highest in hepatopancreas.As PRR,the purifi ed recombinant proteins r Sp CTL-C and r Sp CTL-D have high affi nity for three kinds of pathogen-associated molecular patterns(PAMPs):β-glucan,lipopolysaccharide,and peptidoglycan.Besides,r Sp CTL-D can bind to all nine microorganisms tested,while r Sp CTL-C can bind to seven microorganisms except for Staphylococcus aureus and Micrococcus luteus.Both r Sp CTL-C and r Sp CTL-D showed agglutination activity towards fungi Pichia pastoris and Saccharomyces cerevisiae.However,r Sp CTL-C and r Sp CTL-D exhibited diff erent antimicrobial activities:r Sp CTL-D has a certain inhibitory eff ect on the growth of Vibrio fl uvialis and M.luteus,while r Sp CTL-C has no obvious inhibitory activity.The results show that r Sp CTL-C and r Sp CTL-D had better phagocytosis-promoting eff ect on M.luteus than the negative control.Meanwhile,both r Sp CTL-C and r Sp CTL-D had certain encapsulation-promoting activity.Collectively,two C-type lectins with novel key motifs make an important impact as PRR in immune response towards pathogens.At the same time,they play diff erent functions in the innate immunity of mud crab S.paramamosain.展开更多
基金Supported by the National Key R&D Program of China(No.2023YFD2401005)the Key R&D Program of Ningbo(No.2022Z059)the K.C.Wong Magna Fund of Ningbo University。
文摘Intraspecific conflict induced by the innate aggressiveness is one of the main reasons for the extremely low survival rate in mud crab Scylla paramamosain aquaculture,which have impeded the sustainable culture of the species.In this study,we first classified and quantified the aggressive behavior,and established a crab aggressive behavior model,laying the foundation for subsequent research on evaluating combat intensity.The contents of 5-hydroxytryptamine(5-HT),dopamine(DA),and cAMP in the hemolymph of the mud crabs before and after fighting were measured by high-performance liquid chromatography-mass spectrometry(HPLC-MS),and the mud crabs exhibited a significant increase of 5-HT(P<0.05),while the DA and cAMP decreased significantly(P<0.05).In addition,we applied EthoVision to examine the changes of the crab behavior after DA administration.After 0.5 h of injection,the movement speed,distance,duration of aggressive behavior,and intensity of aggression in the high concentration DA group were significantly higher than those in the saline injection group and the untreated control group(P<0.05).The results of real-time quantitative polymerase chain reaction(qRT PCR)analysis showed that the expression of DA 1 in the thoracic ganglia of the mud crabs was significantly down-regulated in the DA injection group,and the aggressive behavior was weakened.Conversely,DA1 expression was up-regulated when aggressive behavior was strengthened.Besides,there were significant differences in the expression levels of receptor expression genes including 5-HT1,5-HT2,and crustacean hyperglycemic hormone(CHH)in different tissues,indicating that the alteration of aggressive behavior of the mud crab after injection with different concentrations of DA could be regulated by changes in the expression levels of corresponding receptor genes.Our results contribute to a deeper analysis of the aggressive behavior mechanism of the mud crabs and provide a theoretical basis for reducing fighting-related mortalities in aquaculture.
基金Supported by the National Natural Science Foundation of China(No.42276106)the Youth Science and Technology Innovation Leading Talent Project of Ningbo City(No.2023QL038)+4 种基金the Public Welfare Research Project of Ningbo(No.2023S114)the“Three Rural Issues,Nine Parties”Agricultural Science and Technology Collaboration Plan of Zhejiang Province(No.2024SNJF073)the earmarked fund for CARS(No.CARS 48)the Major Scientific and Technological Innovation Project of Wenzhou City(No.ZF2022008)the K.C.Wong Magna Fund in Ningbo University。
文摘The farming of Scylla paramamosain with specific flavors has a higher commercial value,and the flavors are related to the integrated farming environment and non-volatile flavor substances,while the survival environment is one of the important ways to source gut microorganisms in the organism.In this study,the levels of dominant taxa in the gut flora of S.paramamosain from Mong Cai,Vietnam(VN),Taishan City,Guangdong Province(TS)of China,and Ninghai County,Ningbo City(NB)Zhejiang Province of China converged with those of S.paramamosain from Sanmen County,Ningbo City(CK 1,CK 2,and CK 3)at 28 d of domestication.The top 15 genera with the highest abundance of VN,TS,and NB gut flora were the same as CK 1,CK 2,and CK 3,but with different percentages,and gradually converged to CK 1,CK 2,and CK 3,respectively,at 28 d of domestication.Correlation between intestinal flora and non-volatile flavor substances in the hepatopancreas at the percentage level of relative abundance of bacterial genera found that above 28 d of domestication,Muribaculaceae,Psychrilyobacter,Clostridia_vadinBB 60_group,Halarcobacter Carboxylicivirga,Sediminispirochaeta may be the most important genera affecting flavor amino acids of VN.Sediminispirochaeta,Carboxylicivirga,Halarcobacter,Photobacterium,ZOR 0006,Psychrilyobacter,and Pseudomonas may be the most important genera affecting flavor amino acids of NB.Sediminispirochaeta,Carboxylicivirga,Halarcobacter,Photobacterium,ZOR 0006,Vibrio,and Sphingomonas may be the most important genera affecting flavor amino acids of TS.These results show that the intestinal flora structure of crabs from different areas were domesticated in the same area for at least 28 d before they converged to that of the domesticated crab,and the most important genera affecting the flavor amino acids of TS,VN,and NB were also identified.The results of this study provide a reference and basis for the technique of directional cultivation of the flavor quality of the crab.
基金The National Natural Science Foundation of China under contract Nos 40406030 and 40776084the National High Technology Research and Development Program of China under contract No 2006AA10A406the Program for New Century Excellent Talents in Fujian Province University
文摘The identification and localization of vertebrate follicle stimulating hormone （FSH） and luteinizing hormone （LH） in crustaceans may further elucidate the regulation mechanisms in arthropod repro-duction. Using immunocytochemical staining techniques, this study has localized vertebrate FSH-like and LH-like substances in neurons in the subesophageal and thoracic ganglia from the thoracic ganglion mass （TGM） of Scylla paramamosain （Crustacea： Decapoda： Brachyura）. Enzyme-linked immunosorbent assay （ELISA） has shown that the concentrations of both FSH-and LH-like sub-stances increased markedly in the TGM during the vitellogenic stage compared with that in the previtellogenic stage. These results indicate that substances resembling the vertebrate FSH and LH are present in S. paramamosain, and they may be involved in the development of the ovary as well as in ovulation.
基金Supported by the Fundamental Research Funds for the Central Universities(No.20720180100)the National Natural Science Foundation of China(NSFC)(Nos.U1205123,41676158)the Fujian Science and Technology Department(No.2014N2004)
文摘Innexin proteins are a class of transmembrane proteins existing in invertebrates and they have diverse biological functions. The innexin protein Sp-inx2 has been demonstrated to play roles in immune response and promotion of cell apoptosis in the mud crab Scylla paramamosain . One novel innexin gene, named as Sp-inx3 was characterized from S. paramamosin in this study, with an open reading frame of 1 101 bp encoding 367 amino acid residues. Multiple sequence alignment revealed that the Sp-inx3 is highly homologous with innexin3 of Cancer boredis and Homorus americanus . Quantitative real-time PCR (qPCR) and the western blotting results revealed that Sp-inx3 gene was expressed predominantly in the eyestalk, brain, and thoracic ganglion mass in both female and male crabs. The immunohistochemistry assay (IHC) also showed the widespread and intense immunoreactivity of Sp-inx3 in the brain and thoracic ganglion mass. Sp-inx3 mRNA transcription profi les exhibited signifi cantly higher expression from the embryo1 to embryo4 period and low level of expression at the prehatching period and zoea I larva period of S . paramamosain . These results indicate that the Sp-inx3 may play an important role in the nervous system and early embryonic development of S . paramamosain.
基金supported by the grants from the Na-tional Key R&D Program of China(Nos.2018YFD0900303,2018YFD0901304)the Major Science&Technology Spe-cial Project of Zhejiang Province(No.2021C02069-6)the China Agriculture Research System(No.CARS-48),and the KC Wong Magana Fund in Ningbo University.
文摘This study investigated the effects of long-term low-salinity on the growth performance,proximate composition,amino acid and fatty acid profiles of Scylla paramamosain.The salinity of the low-salinity-culture group(LC)and maintained-salinity-cul-ture group(MC)were set at 5 and 25 respectively.After rearing for 30 d,the survival rate(SR)of the LC group was significantly lower,whereas the average daily molting frequency(ADMF)was significantly higher than those in MC group(P<0.05).There were no significant difference for weight gain rate(WGR)and specific growth rate(SGR)between the two groups.The moisture content of the LC group was slightly higher than the MC group without significant difference.The contents of ash,crude lipid and crude pro-tein in the LC group were lower than those in the MC group,but no significant differences were found except for ash content.A total of 17 free amino acids and 23 fatty acids were identified from the muscle of S.paramamosain.The total amino acids(TAA),essen-tial amino acids(EAA)and essential amino acid index(EAAI)had no significant difference between the two groups.The crabs from LC group had a significantly higher HUFA,including EPA,DHA,ARA.The percentage of n-3 PUFA and the ratio of n-3/n-6 PUFA were significantly higher in the LC group.These results indicated that S.paramamosain rearing at low salinity had significantly de-creased SR;however,the low-salinity environment significantly promoted the accumulation of unsaturated fatty acids(UFAs),espe-cially the n-3 PUFA,which might be related to the osmoregulation mechanism.
基金the National Natural Science Foundation of China(No.31772837)the National Key Research&Development Program of China(No.2018YF D0900201)+2 种基金the Science and Technology Project of Guang-dong Province(No.2018A050506080)the Shantou Uni-versity Scientific Research Foundation for Talents(No.NTF17006)the Program for Innovation and Enhance-ment of School of Department of Education of Guang-dong Province(No.2017KCXTD014).
文摘The doublesex and mab-3 related transcription factor(DMRT)gene family is conserved from invertebrates to humans.The functions of DMRT are mainly involved in sex development and the formation of many tissues and organs.In this study,a DM(Doublesex/Mab-3-domain gene was identified in the mud crab Scylla paramamosain,and was named SpDMRT99B because of its many similarities to arthropod DMRT99B and phylogenetically close relationship with arthropod DMRT99B.The cDNA of SpDMRT99B gene is 1249 bp in length,encoding 224 amino acids.From 254 bp to 928 bp there is a conserved DM domain.No transmembrane domain was identified.Through multiple amino acid alignment and phylogenetic tree analysis,the closest gene to SpDMRT99B is Eriocheir sinensis DMRT99B,followed by Macrobrachium rosenbergii and Drosophila melanogaster DMRT99B.The expressions of the gene were characterized in different tissues of female and male crabs during early development period of crab individuals,as well as in different development periods of gonads.The results showed that SpDMRT99B gene is significantly highly expressed in testis than in ovary and other tissues.The expression level of SpDMRT99B in testis at different stages is significantly higher than that in ovary,and it is particularly highly expressed in immature testis.In early developmental stages of larvae,the expressions of SpDMRT99B remain at a low level and reach a peak at zoea stage I when the body segments shape up.It is speculated that SpDMRT99B gene might be involved in the gonadal development process and somitogenesis of S.paramamosain.
基金Supported by the National Natural Science Foundation of China(No.31702375)the Fundamental Research Funds of Zhejiang Sci-Tech University(No.2019Q047)。
文摘As an important pattern recognition receptor(PRR)in the innate immune system,C-type lectin plays an important role in the innate immune process of invertebrates.Two C-type lectins Sp CTL-C and Sp CTL-D were characterized from mud crab(Scylla paramamosain).The predicted Sp CTL-C and Sp CTL-D proteins both contain a single carbohydrate-recognition domain(CRD)with key motif Gln-Pro-Ala(QPA)and Met-Pro-Ala(MPA),respectively.Sp CTL-C and Sp CTL-D transcripts distributed in all examined tissues,and the expression level was the highest in hepatopancreas.As PRR,the purifi ed recombinant proteins r Sp CTL-C and r Sp CTL-D have high affi nity for three kinds of pathogen-associated molecular patterns(PAMPs):β-glucan,lipopolysaccharide,and peptidoglycan.Besides,r Sp CTL-D can bind to all nine microorganisms tested,while r Sp CTL-C can bind to seven microorganisms except for Staphylococcus aureus and Micrococcus luteus.Both r Sp CTL-C and r Sp CTL-D showed agglutination activity towards fungi Pichia pastoris and Saccharomyces cerevisiae.However,r Sp CTL-C and r Sp CTL-D exhibited diff erent antimicrobial activities:r Sp CTL-D has a certain inhibitory eff ect on the growth of Vibrio fl uvialis and M.luteus,while r Sp CTL-C has no obvious inhibitory activity.The results show that r Sp CTL-C and r Sp CTL-D had better phagocytosis-promoting eff ect on M.luteus than the negative control.Meanwhile,both r Sp CTL-C and r Sp CTL-D had certain encapsulation-promoting activity.Collectively,two C-type lectins with novel key motifs make an important impact as PRR in immune response towards pathogens.At the same time,they play diff erent functions in the innate immunity of mud crab S.paramamosain.
