Ocean warming is altering the habitats of marine invertebrates,which has resulted in an increased physiological stress to marine molluscs,especially those intertidal bivalves,such as the ark shell Scapharca broughtoni...Ocean warming is altering the habitats of marine invertebrates,which has resulted in an increased physiological stress to marine molluscs,especially those intertidal bivalves,such as the ark shell Scapharca broughtonii.We investigated the physiological and transcriptional responses of ark shells to acute and chronic thermal stress results showed that at 33℃,a significantly higher cumulative mortality(55.7%)occurred under acute thermal stress than chronic thermal stress.The apoptosis rate of hemocytes was sustained at higher levels and the necrosis rate was increased significantly in a time-dependent manner under acute thermal stress.However,under chronic thermal stress,the apoptosis and necrosis rates exhibited similar change trends:a rapid increase followed by a gradual decline and sustained at a relatively high level until the end of the experiment.The expressions of heat shock protein genes(HSP20 and HSP90),apoptosis-related genes(TRAF6,GRP78,NIX,and Casp-3),antioxidative-related genes(GST and MRP)and cellular detoxification-related genes(HbⅡB,NOS-1,HO-1,and ENO-1)were upregulated significantly under both acute and chronic thermal stresses.These results demonstrated that the anti-apoptotic system,antioxidant defense system,cellular detoxification system,and heat shock proteins(HSPs)played vital roles for ark shells in response to thermal stress.As acute thermal stress can result in irreversible damage to marine molluscs,it is thus advised that chronic thermal stress should be used to select thermal-resistant ark shell strains.展开更多
By air-dry method, the karyotype from gill cell in three clams of Bivalvia Pterimorphia Arcidae,Tegillarca granosa,Scapharca subcrenata and S.broughtonii,was studied. Their chromosome number (2n ) andfundamenod number...By air-dry method, the karyotype from gill cell in three clams of Bivalvia Pterimorphia Arcidae,Tegillarca granosa,Scapharca subcrenata and S.broughtonii,was studied. Their chromosome number (2n ) andfundamenod number (W) are equal to each other. But their karyotype is different. In T. granosa, it is 2n = 38,28m+ 10sml In S.subcrenata2n = 38, 14m + 22sm+ 2st, In S.broughtonii 2n = 38, 12m+ 20sm+ 6st. T.granosa has no subtelocentric (st) chromosome, S.subcrenata has one Pair and S. then has three paris of st.Middle centric (m) and submiddle centric chromosome are major type in karyotype of three species of Arcida; thelengths of chromosomes from the largest to the smallest changed gradually. The absolute length of the maximum chromosome in all three species do not exceed 5 μm and the minimum cluomonsome is about 2 μm. Inversion pericentricperhaps plays an important role in the evolution of chromosome. Hybridization among the three species of Arcidae ispossible.展开更多
Release programs to enhance stocks of ark shell(Anadara broughtonii) have been undertaken in a number of Asian countries,but their effectiveness has rarely been investigated owing to a lack of marking methods.The qual...Release programs to enhance stocks of ark shell(Anadara broughtonii) have been undertaken in a number of Asian countries,but their effectiveness has rarely been investigated owing to a lack of marking methods.The quality and longevity of fluorescent markers,alizarin red S(ARS) and calcein(CAL)(200 and 300 mg/L),as well as clip tags,were tested on juvenile A.broughtonii.No significant differences in survival or shell growth were observed in juveniles stained with either of the two fluorochromes after a 160-day culture period,but the retention rate was 100%after 1 year.Fluorescent marks(>grade 3) were observable microscopically in juveniles stained with the two fluorochromes,and some fluorescent marks(>grade 4) were visible with the naked eye after 1 year.ARS-marked shells were brighter than those marked with CAL,and shells marked with 300 mg/L of the fluorochromes were easier to detect than those marked with 200 mg/L.Clip tags were incorporated into the shell as the bivalve grew,and the retention rate was64.25%after 160 days.Significant differences in survival(at 30 days),shell length(at 60,90,120,and 160days),and wet weight(at 90,120,and 160 days) were observed between the clip-tagged and control groups(all P<0.05),indicating that the tags may have passive effects on the ark shell.The results suggest that both ARS and CAL are suitable to mark A.broughtonii for large-scale restocking programs,and that optimal marking quality was achieved with 300 mg/L ARS.Lighter and smaller clip tags need to be developed to reduce injury and increase survival rate of clams.展开更多
Scapharca broughtonii is a commercially important and over-exploited species.In order to investigate its genetic diversity and population structure,43 novel polymorphic microsatellites were isolated and characterized....Scapharca broughtonii is a commercially important and over-exploited species.In order to investigate its genetic diversity and population structure,43 novel polymorphic microsatellites were isolated and characterized.The number of alleles per locus ranged from 3 to 22 with an average of 6.93,and the observed and expected heterozygosities varied between 0.233 and 1.000,and 0.250 and 0.953,with an average of 0.614 and 0.707,respectively.Three highly informative multiplex PCRs were developed from nine of those microsatellites for S.broughtonii.We evaluated and validated these multiplex PCRs in 8 full-sib families.The average polymorphism information content(PIC) was 0.539.The frequency of null alleles was estimated as 3.13% of all the alleles segregation based on a within-family analysis of Mendelian segregation patterns.Parentage analysis of real offspring demonstrated that 100% of all offspring were unambiguously allocated to a pair of parents based on 3 multiplex sets.Those 43 microsatellite loci with high variability will be helpful for the analysis of population genetics and conservation of wild stock of S.broughtonii.The 3 sets of multiplex PCRs could be an important tool of pedigree reconstruction,population genetic analysis and brood stock management.展开更多
In order to study the food consumption, preference and day-night predatorydifference of Asterias amurensis on Scapharca broughtonii, the experiments werecarried out at the temperatures ranging from 16 ℃ to 20 ℃, sal...In order to study the food consumption, preference and day-night predatorydifference of Asterias amurensis on Scapharca broughtonii, the experiments werecarried out at the temperatures ranging from 16 ℃ to 20 ℃, salinity of 28.2 ± 2.1,dissolved oxygen of 7.5±0.7 mg/L and pH of 8.0 ± 0.3.The results provided basic datafor promoting steady and healthy development of the multiplication and cultivation of S.broughtonii. The results of food consumption suggested that the food intake of starfishincreased with the density of S. broughtonii at all conditions. The food consumption ofstarfish in different sizes on S. broughtonii in the same size had no significant difference(p>0.05), but it was significantly different among S. broughtonii in different sizes. Thestarfish had the highest feeding rate on the smallest S. broughtonii. Our findings alsoverified the positive relation between the weight of food intake of starfish in differentsizes on the density and size of S. broughtonii. The feeding rhythm of starfish onS. broughtonii in different sizes showed a certain day-night difference, higher at nightthan in the day. The maximum food consumption occurred when the size of S.broughtonii became larger. The results showed that 30 ind/m2 was the suitable seabottom sowing density for S. broughtonii. Our data indicated that the ability to avoidpredators and rivals increased as the shell length rose. Based on prey selectivity,bivalves that have a lower commercial value may be used to clear away A. amurensis.展开更多
Anadara broughtonii is one of the main commercially important species of shellfish in northern China.A.broughtonii lives in relatively stable subtidal zone where the clam could respond to environmental changes with mi...Anadara broughtonii is one of the main commercially important species of shellfish in northern China.A.broughtonii lives in relatively stable subtidal zone where the clam could respond to environmental changes with minimum energy.Therefore,slight fluctuations in water environment may have a great impact on physiological processes such as feeding and metabolism.Large-scale mortality often occurs during the intermediate rearing processes,and high temperatures in summer are considered the leading cause of mortality.To understand the physiological and molecular response patterns of A.broughtonii at high temperatures and to estimate the appropriate metabolism temperature for A.broughtonii,the effects of temperature on the respiratory metabolism and food intake at different growth stages were studied.The response patterns of heat shock protein genes to heat stress and post-stress recovery were also explored.Results show that the temperature and growth stage of A.broughtonii were two important factors affecting metabolism and feeding.The optimum temperature for feeding and physiological activities in each shell-length group was 24℃.The temperature at which the peak metabolic rate occurred in each shell-length group increased with the increase in shell length.With the increase in heat stress,the expression of three heat shock protein genes(Abhsp60,Abhsp70,and Abhsp90)in the tissues of two size groups of A.broughtonii increased significantly when temperature was above 24℃and reached a peak at 30℃.After heat shock at 30℃for 2 h,the expression of the three heat shock protein genes rapidly increased,peaked at 2 h after the heat shock,and then gradually decreased to the level of the control group at 48 h after the heat shock.The three heat shock protein genes respond rapidly to heat stress and can be used as indicators to the cellular stress response in A.broughtonii under an environmental stress.展开更多
Mitochondrial gene(16S rRNA and COI) fragments of Bloody clam Scapharca broughtonii were amplified via PCR, the PCR products were ligated into T vectors, cloned and sequenced. 823 bp and 703 bp nucleotide sequences of...Mitochondrial gene(16S rRNA and COI) fragments of Bloody clam Scapharca broughtonii were amplified via PCR, the PCR products were ligated into T vectors, cloned and sequenced. 823 bp and 703 bp nucleotide sequences of partial 16S rRNA gene and partial COI gene were obtained respectively. The contents of A, T, G and C were 24.79%,23.57%,29.16% and 22.48% in 16S rDNA; 22.05%,33.85%,23.33% and 20.77% in COI. The potential uses of these two sequences were discussed for genetic variation, differentiation and relevant research of different geographic populations in the species.展开更多
基金Supported by the National Key R&D Program of China(No.2019YFD0900704)the National Natural Science Foundation of China(No.31972791)the Earmarked Fund for Shandong Modern AgroIndustry Technology Research System(No.SDAIT-14)。
文摘Ocean warming is altering the habitats of marine invertebrates,which has resulted in an increased physiological stress to marine molluscs,especially those intertidal bivalves,such as the ark shell Scapharca broughtonii.We investigated the physiological and transcriptional responses of ark shells to acute and chronic thermal stress results showed that at 33℃,a significantly higher cumulative mortality(55.7%)occurred under acute thermal stress than chronic thermal stress.The apoptosis rate of hemocytes was sustained at higher levels and the necrosis rate was increased significantly in a time-dependent manner under acute thermal stress.However,under chronic thermal stress,the apoptosis and necrosis rates exhibited similar change trends:a rapid increase followed by a gradual decline and sustained at a relatively high level until the end of the experiment.The expressions of heat shock protein genes(HSP20 and HSP90),apoptosis-related genes(TRAF6,GRP78,NIX,and Casp-3),antioxidative-related genes(GST and MRP)and cellular detoxification-related genes(HbⅡB,NOS-1,HO-1,and ENO-1)were upregulated significantly under both acute and chronic thermal stresses.These results demonstrated that the anti-apoptotic system,antioxidant defense system,cellular detoxification system,and heat shock proteins(HSPs)played vital roles for ark shells in response to thermal stress.As acute thermal stress can result in irreversible damage to marine molluscs,it is thus advised that chronic thermal stress should be used to select thermal-resistant ark shell strains.
文摘By air-dry method, the karyotype from gill cell in three clams of Bivalvia Pterimorphia Arcidae,Tegillarca granosa,Scapharca subcrenata and S.broughtonii,was studied. Their chromosome number (2n ) andfundamenod number (W) are equal to each other. But their karyotype is different. In T. granosa, it is 2n = 38,28m+ 10sml In S.subcrenata2n = 38, 14m + 22sm+ 2st, In S.broughtonii 2n = 38, 12m+ 20sm+ 6st. T.granosa has no subtelocentric (st) chromosome, S.subcrenata has one Pair and S. then has three paris of st.Middle centric (m) and submiddle centric chromosome are major type in karyotype of three species of Arcida; thelengths of chromosomes from the largest to the smallest changed gradually. The absolute length of the maximum chromosome in all three species do not exceed 5 μm and the minimum cluomonsome is about 2 μm. Inversion pericentricperhaps plays an important role in the evolution of chromosome. Hybridization among the three species of Arcidae ispossible.
基金Supported by the Special Fund for Agro-Scientific Research in the Public Interest(No.201003068)the National Department Public Benefit Research Foundation(No.201305043)
文摘Release programs to enhance stocks of ark shell(Anadara broughtonii) have been undertaken in a number of Asian countries,but their effectiveness has rarely been investigated owing to a lack of marking methods.The quality and longevity of fluorescent markers,alizarin red S(ARS) and calcein(CAL)(200 and 300 mg/L),as well as clip tags,were tested on juvenile A.broughtonii.No significant differences in survival or shell growth were observed in juveniles stained with either of the two fluorochromes after a 160-day culture period,but the retention rate was 100%after 1 year.Fluorescent marks(>grade 3) were observable microscopically in juveniles stained with the two fluorochromes,and some fluorescent marks(>grade 4) were visible with the naked eye after 1 year.ARS-marked shells were brighter than those marked with CAL,and shells marked with 300 mg/L of the fluorochromes were easier to detect than those marked with 200 mg/L.Clip tags were incorporated into the shell as the bivalve grew,and the retention rate was64.25%after 160 days.Significant differences in survival(at 30 days),shell length(at 60,90,120,and 160days),and wet weight(at 90,120,and 160 days) were observed between the clip-tagged and control groups(all P<0.05),indicating that the tags may have passive effects on the ark shell.The results suggest that both ARS and CAL are suitable to mark A.broughtonii for large-scale restocking programs,and that optimal marking quality was achieved with 300 mg/L ARS.Lighter and smaller clip tags need to be developed to reduce injury and increase survival rate of clams.
基金supported by National Marine Public Welfare Research Program(201205023)National Natural Science Foundation of China(41276138)Doctoral Program of Ministry of Education of China(2013 0132110009)
文摘Scapharca broughtonii is a commercially important and over-exploited species.In order to investigate its genetic diversity and population structure,43 novel polymorphic microsatellites were isolated and characterized.The number of alleles per locus ranged from 3 to 22 with an average of 6.93,and the observed and expected heterozygosities varied between 0.233 and 1.000,and 0.250 and 0.953,with an average of 0.614 and 0.707,respectively.Three highly informative multiplex PCRs were developed from nine of those microsatellites for S.broughtonii.We evaluated and validated these multiplex PCRs in 8 full-sib families.The average polymorphism information content(PIC) was 0.539.The frequency of null alleles was estimated as 3.13% of all the alleles segregation based on a within-family analysis of Mendelian segregation patterns.Parentage analysis of real offspring demonstrated that 100% of all offspring were unambiguously allocated to a pair of parents based on 3 multiplex sets.Those 43 microsatellite loci with high variability will be helpful for the analysis of population genetics and conservation of wild stock of S.broughtonii.The 3 sets of multiplex PCRs could be an important tool of pedigree reconstruction,population genetic analysis and brood stock management.
基金supported by the National Sea Welfare Project(201205023)China Agriculture Research System(CARS-48)the earmarked fund for Modern Agro-industry Technology Research System in Shandong Province(SDAIT-14)
文摘In order to study the food consumption, preference and day-night predatorydifference of Asterias amurensis on Scapharca broughtonii, the experiments werecarried out at the temperatures ranging from 16 ℃ to 20 ℃, salinity of 28.2 ± 2.1,dissolved oxygen of 7.5±0.7 mg/L and pH of 8.0 ± 0.3.The results provided basic datafor promoting steady and healthy development of the multiplication and cultivation of S.broughtonii. The results of food consumption suggested that the food intake of starfishincreased with the density of S. broughtonii at all conditions. The food consumption ofstarfish in different sizes on S. broughtonii in the same size had no significant difference(p>0.05), but it was significantly different among S. broughtonii in different sizes. Thestarfish had the highest feeding rate on the smallest S. broughtonii. Our findings alsoverified the positive relation between the weight of food intake of starfish in differentsizes on the density and size of S. broughtonii. The feeding rhythm of starfish onS. broughtonii in different sizes showed a certain day-night difference, higher at nightthan in the day. The maximum food consumption occurred when the size of S.broughtonii became larger. The results showed that 30 ind/m2 was the suitable seabottom sowing density for S. broughtonii. Our data indicated that the ability to avoidpredators and rivals increased as the shell length rose. Based on prey selectivity,bivalves that have a lower commercial value may be used to clear away A. amurensis.
基金Supported by the Marine S&T Fund of Shandong Province for Pilot National Laboratory for Marine Science and Technology(Qingdao)(No.2018SDKJ0501-4)the National Key Research and Development Program(No.2019YFD0901303)。
文摘Anadara broughtonii is one of the main commercially important species of shellfish in northern China.A.broughtonii lives in relatively stable subtidal zone where the clam could respond to environmental changes with minimum energy.Therefore,slight fluctuations in water environment may have a great impact on physiological processes such as feeding and metabolism.Large-scale mortality often occurs during the intermediate rearing processes,and high temperatures in summer are considered the leading cause of mortality.To understand the physiological and molecular response patterns of A.broughtonii at high temperatures and to estimate the appropriate metabolism temperature for A.broughtonii,the effects of temperature on the respiratory metabolism and food intake at different growth stages were studied.The response patterns of heat shock protein genes to heat stress and post-stress recovery were also explored.Results show that the temperature and growth stage of A.broughtonii were two important factors affecting metabolism and feeding.The optimum temperature for feeding and physiological activities in each shell-length group was 24℃.The temperature at which the peak metabolic rate occurred in each shell-length group increased with the increase in shell length.With the increase in heat stress,the expression of three heat shock protein genes(Abhsp60,Abhsp70,and Abhsp90)in the tissues of two size groups of A.broughtonii increased significantly when temperature was above 24℃and reached a peak at 30℃.After heat shock at 30℃for 2 h,the expression of the three heat shock protein genes rapidly increased,peaked at 2 h after the heat shock,and then gradually decreased to the level of the control group at 48 h after the heat shock.The three heat shock protein genes respond rapidly to heat stress and can be used as indicators to the cellular stress response in A.broughtonii under an environmental stress.
文摘Mitochondrial gene(16S rRNA and COI) fragments of Bloody clam Scapharca broughtonii were amplified via PCR, the PCR products were ligated into T vectors, cloned and sequenced. 823 bp and 703 bp nucleotide sequences of partial 16S rRNA gene and partial COI gene were obtained respectively. The contents of A, T, G and C were 24.79%,23.57%,29.16% and 22.48% in 16S rDNA; 22.05%,33.85%,23.33% and 20.77% in COI. The potential uses of these two sequences were discussed for genetic variation, differentiation and relevant research of different geographic populations in the species.
