Background Hypoxia is a pervasive challenge in aquaculture that poses a significant threat to aquatic organisms.Since fish cannot synthesize vitamin A endogenously,it must be supplied through diet,and it plays a vital...Background Hypoxia is a pervasive challenge in aquaculture that poses a significant threat to aquatic organisms.Since fish cannot synthesize vitamin A endogenously,it must be supplied through diet,and it plays a vital role in supporting fish stress resistance.This study aimed to investigate the protective effects of VA on the gills of adult grass carp(Ctenopharyngodon idella)against hypoxia and to elucidate the underlying mechanisms.Methods Six experimental diets with graded VA levels(375,862,1,614,2,099,2,786,and 3,118 IU/kg)were fed to grass carp(initial weight:726±1.2 g)for 60 d.After the trial,24 fish per treatment were selected,divided equally into normoxic and hypoxic groups,fasted for 24 h,and then subjected to a 96-h acute hypoxic challenge.Results The results demonstrated that VA supplementation mitigated hypoxia-induced damage in gill tissue,as evidenced by histological examination.Furthermore,VA alleviated oxidative stress,as indicated by reduced levels of lactate(LD),lactate dehydrogenase(LDH),reactive oxygen species(ROS),protein carbonyl(PC),and malondialdehyde(MDA).Further investigations indicated that VA alleviated mitochondrial stress,potentially through suppressing the canonical UPR^(mt) axis while activating both the UPR^(mt) sirtuin axis and the UPRIMS/Erα axis.VA also modulated mitochondrial mass via multiple mechanisms,including the promotion of mitochondrial biogenesis,maintenance of dynamics by stimulating fusion and reducing fission,and inhibition of mitophagy.The suppression of mitophagy likely involved downregulating both the Pink1/Parkin-dependent pathway and the Hif1a-Bnip3 pathway.Taken together,these adaptations suggested an essential role for VA in preserving mitochondrial homeostasis.Based on the quadratic regression analysis of ROS and MDA levels from the hypoxic group,the estimated VA requirements for adult grass carp were 2,013 and 2,056 IU/kg diet,respectively.Conclusions In summary,this study provided the first evidence that VA conferred protective effects against hypoxiainduced gill damage in grass carp.展开更多
Background As living standards improve,consumers are placing greater emphasis on the enhancement of fish flesh quality,making its improvement increasingly critical.Plant-derived polysaccharides positively affect the i...Background As living standards improve,consumers are placing greater emphasis on the enhancement of fish flesh quality,making its improvement increasingly critical.Plant-derived polysaccharides positively affect the improvement of animal flesh quality.Panax ginseng leaf polysaccharides(PGLP)have a similar composition and lower cost compared with Panax ginseng root polysaccharides.However,its function and application effects in grass carp(Ctenopharyngodon idella)are unclear.Methods A total of 540 sub-adult grass carp(679±1.29 g),one of the important economic fish species,were used as experimental models and fed diets supplemented with 0,100,200,300,400,or 500 mg/kg PGLP for 60 d.After 60 d,grass carp were weighed,and their muscles were collected to explore the effects of PGLP on the growth and development of myofibers and energy metabolism-related parameters.Results Our study found that PGLP increased the growth performance and muscle nutritional composition as well as improved muscle hardness,springiness,cohesiveness,chewiness,and hyperplasia of myofibers of sub-adult grass carp.Besides,PGLP promoted muscle energy metabolism by increasing creatine,glycogen,pyruvate,and acetyl-CoA contents and creatine kinase(CK),pyruvate kinase(PK),phosphofructokinase(PFK),and hexokinase(HK)activities,while decreasing lactate dehydrogenase(LDH)activity and lactate content in fish muscle.Finally,our study found that PGLP enhanced mitochondrial function by increasing the protein expression of mitochondrial complexes I–V,biogenesis,and fusion and decreasing autophagy and fission in fish muscle.Conclusions PGLP improved growth performance and flesh quality of sub-adult grass carp,which may be related to enhancing hyperplasia of myofibers by promoting energy metabolism.We concluded that the recommended amount of PGLP in sub-adult grass carp feed to optimize growth performance is 100–200 mg/kg.This study provides a theoretical basis for the application of PGLP in fish feed and for the analysis of the mechanism of nutrition and feed regulating fish flesh quality,which is of great significance.展开更多
Background Ochratoxin A(OTA)is a toxin widely found in aquafeed ingredients,and hypoxia is a common prob-lem in fish farming.In practice,aquatic animals tend to be more sensitive to hypoxia while feeds are contaminate...Background Ochratoxin A(OTA)is a toxin widely found in aquafeed ingredients,and hypoxia is a common prob-lem in fish farming.In practice,aquatic animals tend to be more sensitive to hypoxia while feeds are contaminated with OTA,but no studies exist in this area.This research investigated the multiple biotoxicities of OTA and hypoxia combined on the liver of grass carp and explored the mitigating effect of curcumin(CUR).Methods A total of 720 healthy juvenile grass carp(11.06±0.05 g)were selected and assigned randomly to 4 experi-mental groups:control group(without OTA and CUR),1.2 mg/kg OTA group,400 mg/kg CUR group,and 1.2 mg/kg OTA+400 mg/kg CUR group with three replicates each for 60 d.Subsequently,32 fish were selected,divided into nor-moxia(18 fish)and hypoxia(18 fish)groups,and subjected to hypoxia stress for 96 h.Results CUR can attenuate histopathological damage caused by coming to OTA and hypoxia by reducing vacu-olation and nuclear excursion.The alleviation of this damage was associated with the attenuation of apoptosis in the mitochondrial pathway by decreasing the expression of the pro-apoptotic proteins Caspase 3,8,9,Bax,and Apaf1 while increasing the expression of the anti-apoptotic protein Bcl-2,and attenuation of endoplasmic reticulum stress(ERS)by reducing Grp78 expression and chop levels.This may be attributed to the fact that the addi-tion of CUR increased the levels of catalase(CAT)and glutathione reductase(GSH),increased antioxidant capacity,and ensured the proper functioning of respiratory chain complexes I and II,which in turn reduced the high produc-tion of reactive oxygen species(ROS),thus alleviating apoptosis and ERS.Conclusions In conclusion,our data demonstrate the effectiveness of CUR in attenuating liver injury caused by the combination of OTA and hypoxia.This study confirms the feasibility and efficacy of adding natural products to mitigate toxic damage to aquatic animals.展开更多
Teleost peripheral blood contains a remarkably high proportion of B cells,accounting for 15%-50%of circulating lymphocytes.However,their immune responses to bacterial infection are yet to be elucidated.In the present ...Teleost peripheral blood contains a remarkably high proportion of B cells,accounting for 15%-50%of circulating lymphocytes.However,their immune responses to bacterial infection are yet to be elucidated.In the present study,10×Genomics single-cell RNA sequencing(scRNA-seq)was employed to characterize the transcriptomic landscape of peripheral blood IgM^(+)B cells in grass carp(Ctenopharyngodon idella)following challenge with Aeromonas hydrophila,a major aquatic pathogen.Six transcriptionally distinct IgM^(+)B cell subpopulations were identified,including(im)mature B cells,innate B cells,proliferating B cells,IgD^(high)B cells,and two infection-induced subsets denoted as infectionⅠandⅡB cells.Bacterial infection altered the cellular heterogeneity of IgM^(+)B cells,triggered metabolic reprogramming in(im)mature and innate B cell subpopulations,and enhanced the immunological activation of circulating B cells.Notably,infectionⅠB cells demonstrated robust induction of interferonφ1(IFNφ1),a type I IFN,following A.hydrophila exposure.This induction was further validated through in vitro bacterial stimulation,indicating that teleost B cells actively contribute to innate antibacterial responses through IFN signaling.Additionally,the IgD^(high)B cell subpopulation remained consistently present in peripheral blood across both infected and uninfected states,pointing to a constitutive and likely mature phenotype.These findings significantly advance our understanding of the heterogeneity of peripheral blood IgM^(+)B cells and provide new insights into IgM^(+)B cell-mediated immune responses in teleost fish.展开更多
The current investigation focuses on intertwined relationships of ecology and aquaculture for the benefit of farmers involved in fish farming practices.The study evaluated glucosinolate reduction in black,brown,and wh...The current investigation focuses on intertwined relationships of ecology and aquaculture for the benefit of farmers involved in fish farming practices.The study evaluated glucosinolate reduction in black,brown,and white mustard meals as fish feed ingredients for Indian Major Carps.Fish were fed with 10%mustard meal-supplemented diets in three forms:Raw(R),Anti-nutritional Rich(AR),and Anti-nutritional Lowered(AL),alongside a control group using floating feed.The three-month indoor experiment(September-November 2023)was conducted in FRP tanks with triplicate treatments.Blood analysis revealed compromised health in AR-fed carps,with reduced hemoglobin levels in rohu,catla and mrigal and elevated total leukocyte counts indicating inflammation in all the three carps studied here.Liver function was impaired in AR-fed fish,shown by increased alanine transaminase levels,highest in rohu followed by mrigal and catla.Histopathological examination of AR-fed carps liver tissue revealed necrotic spots,deformed hepatocytes,and significant vacuolation.In contrast,AL-fed fish demonstrated improved health parameters through Complete Blood Count analysis,liver function tests,and histo-pathological observations,suggesting successful reduction of anti-nutritional factors in the processed mustard meals.In near future,replacement of unprocessed seed meal with processed seed meal will lead to economic gains in fish farming.展开更多
池塘养殖是我国主要的养殖模式,也是潜在的温室气体排放源。为探究典型草鱼养殖池塘二氧化碳(CO2)、甲烷(CH4)、氧化亚氮(N2O)通量特征及其驱动因素,以1龄(GC1)、2龄(GC2)和3龄(GC3)草鱼养殖池塘为对象,采用静态箱-气相色谱法原位监测...池塘养殖是我国主要的养殖模式,也是潜在的温室气体排放源。为探究典型草鱼养殖池塘二氧化碳(CO2)、甲烷(CH4)、氧化亚氮(N2O)通量特征及其驱动因素,以1龄(GC1)、2龄(GC2)和3龄(GC3)草鱼养殖池塘为对象,采用静态箱-气相色谱法原位监测气体通量,分析其排放强度及与环境因子的关系。结果显示,温室气体通量依次为GC3>GC2>GC1,GC3的CO2、CH4和N2O平均通量分别为42.30、13.31 mg/(m2·h)和567.25μg/(m2·h),所有池塘均为CH4的排放源。冗余分析表明,GC1气体通量主要受NO3-N和底泥温度影响,GC2以水温为主导,GC3则受底泥温度和溶解氧控制。直接排放系数分析显示,GC3池塘CO2、CH4和N2O排放系数分别为132.98、41.91和1.77 g/kg,均显著高于GC1和GC2(P<0.05)。单位面积增温潜势表现为GC3 (53.48 t CO2-eq/hm2)>GC2(31.84 t CO2-eq/hm2)>GC1 (6.54 t CO2-eq/hm2),差异显著(P<0.05)。单位产量温室气体排放强度在GC1、GC2和GC3中分别为0.26、1.05和1.95 t CO2-eq/t,差异显著(P<0.05)。养殖规格显著影响草鱼池塘温室气体排放强度,高温与大规格养殖加剧碳排放,建议通过调控养殖结构与环境因子,推动渔业碳中和。展开更多
The genomes of three groups of grass carp, namely the Xiangjiang River grass carp group （Xiangjiang group）, a one-generation artificially induced meio-gynogenetic grass carp group （meio-gynogenetic-1 group）, and a...The genomes of three groups of grass carp, namely the Xiangjiang River grass carp group （Xiangjiang group）, a one-generation artificially induced meio-gynogenetic grass carp group （meio-gynogenetic-1 group）, and a two-generation artificially induced meio-gynogenetic grass carp group （meio-gynogenetic-2 group）, were comparatively analyzed with microsatellite markers. Genetic polymorphism had been observed in the Xiangjiang group and most of the examined loci had more than two alleles. But the degree of genetic diversity was not very high. Although all the examined genetic loci in the analyzed individuals were in homozygous state, the genotypes of different individuals of the group were not identical in the meio-gynogenetic-1 group. In the meio-gynogenetic-2 group, not only the examined genetic loci of each individual were homozygous but also the genotypes of all the analyzed individuals of the group were the same. These results suggested that the examined meio-gynogenetic-2 group is a homozygous group and homozygous clone could be produced by continuous artificial induction of gynogenesis for two generations. It was found that the polymorphism existed not only at the allele level but also at the locus level; many alleles of the microsatellite loci and some of the microsatellite loci had been lost during the process of artificial gynogenesis. Therefore, both protection of the diversity of natural grass carp resource and selection of homozygous traits with desired economic genotypes are very important aspects for grass carp breeding.展开更多
[ Objective] The aim of this study was to investigate the growth and morphological characteristics of juvenile hybrids of grass carp. [Method] Three inbred generations of YR （Yangtze River stock ♀×Yangtze River...[ Objective] The aim of this study was to investigate the growth and morphological characteristics of juvenile hybrids of grass carp. [Method] Three inbred generations of YR （Yangtze River stock ♀×Yangtze River stock ♂ ）, ZR （Zhujiang River stock ♀ ×Zhujiang River stock♂ ） and hybrids F1 （ Yangtze River stock ♀ × Zhujiang River stock ♂ ） were established, and their growth or morphological data were also measured. [ Result] The orders of body weight, standard length and absolute growth rate were F1 〉 ZR 〉 YR. No significant difference was found in body weight or standard length of 50 day-old generations （ P〉0. 05）, while there was an extremely significantly difference in those of 170 day-old generations （ P 〈0.01 ）. However, the absolute growth rate of F1 was 20.00% and 50.00% higher than that of ZR and YR respectively, and no significant difference was found between F1 and ZR （ P 〉 0.05）, but significant difference between F1 and YR （ P 〈 0.05）. F1 showed a significant hybrid vigor with rate of 20.09%. There was no significant difference among three inbred generations in standard length/total length （ P 〉 0.05）, while significant difference in head length/total length, body height/standard length and body width/standard length （ P 〈 0.05）, which indicated that F1 had the characteristics of shorter head, higher and wider body. [ Conclusion]F1 has advantages in growth performance and morphological characteristics.展开更多
基金funded by the Sichuan Science and Technology Program(2024YFNH0016)the earmarked fund for CARS(CARS-45)+1 种基金the National Science Fund for Distinguished Young Scholars of China(32425056)the National Key R&D Program of China(2023YFD2400600)。
文摘Background Hypoxia is a pervasive challenge in aquaculture that poses a significant threat to aquatic organisms.Since fish cannot synthesize vitamin A endogenously,it must be supplied through diet,and it plays a vital role in supporting fish stress resistance.This study aimed to investigate the protective effects of VA on the gills of adult grass carp(Ctenopharyngodon idella)against hypoxia and to elucidate the underlying mechanisms.Methods Six experimental diets with graded VA levels(375,862,1,614,2,099,2,786,and 3,118 IU/kg)were fed to grass carp(initial weight:726±1.2 g)for 60 d.After the trial,24 fish per treatment were selected,divided equally into normoxic and hypoxic groups,fasted for 24 h,and then subjected to a 96-h acute hypoxic challenge.Results The results demonstrated that VA supplementation mitigated hypoxia-induced damage in gill tissue,as evidenced by histological examination.Furthermore,VA alleviated oxidative stress,as indicated by reduced levels of lactate(LD),lactate dehydrogenase(LDH),reactive oxygen species(ROS),protein carbonyl(PC),and malondialdehyde(MDA).Further investigations indicated that VA alleviated mitochondrial stress,potentially through suppressing the canonical UPR^(mt) axis while activating both the UPR^(mt) sirtuin axis and the UPRIMS/Erα axis.VA also modulated mitochondrial mass via multiple mechanisms,including the promotion of mitochondrial biogenesis,maintenance of dynamics by stimulating fusion and reducing fission,and inhibition of mitophagy.The suppression of mitophagy likely involved downregulating both the Pink1/Parkin-dependent pathway and the Hif1a-Bnip3 pathway.Taken together,these adaptations suggested an essential role for VA in preserving mitochondrial homeostasis.Based on the quadratic regression analysis of ROS and MDA levels from the hypoxic group,the estimated VA requirements for adult grass carp were 2,013 and 2,056 IU/kg diet,respectively.Conclusions In summary,this study provided the first evidence that VA conferred protective effects against hypoxiainduced gill damage in grass carp.
基金supported by National Natural Science Foundation of China(U23A20250)the earmarked fund for CARS(CARS-45)+2 种基金the National Key R&D Program of China(2023YFD2400600)Sichuan Provincial Science and Technology Innovation Talent Project(2023JDRC0043)Sichuan Innovation Team of National Modern Agricultural Industry Technology System(SCCXTD-2024-15)。
文摘Background As living standards improve,consumers are placing greater emphasis on the enhancement of fish flesh quality,making its improvement increasingly critical.Plant-derived polysaccharides positively affect the improvement of animal flesh quality.Panax ginseng leaf polysaccharides(PGLP)have a similar composition and lower cost compared with Panax ginseng root polysaccharides.However,its function and application effects in grass carp(Ctenopharyngodon idella)are unclear.Methods A total of 540 sub-adult grass carp(679±1.29 g),one of the important economic fish species,were used as experimental models and fed diets supplemented with 0,100,200,300,400,or 500 mg/kg PGLP for 60 d.After 60 d,grass carp were weighed,and their muscles were collected to explore the effects of PGLP on the growth and development of myofibers and energy metabolism-related parameters.Results Our study found that PGLP increased the growth performance and muscle nutritional composition as well as improved muscle hardness,springiness,cohesiveness,chewiness,and hyperplasia of myofibers of sub-adult grass carp.Besides,PGLP promoted muscle energy metabolism by increasing creatine,glycogen,pyruvate,and acetyl-CoA contents and creatine kinase(CK),pyruvate kinase(PK),phosphofructokinase(PFK),and hexokinase(HK)activities,while decreasing lactate dehydrogenase(LDH)activity and lactate content in fish muscle.Finally,our study found that PGLP enhanced mitochondrial function by increasing the protein expression of mitochondrial complexes I–V,biogenesis,and fusion and decreasing autophagy and fission in fish muscle.Conclusions PGLP improved growth performance and flesh quality of sub-adult grass carp,which may be related to enhancing hyperplasia of myofibers by promoting energy metabolism.We concluded that the recommended amount of PGLP in sub-adult grass carp feed to optimize growth performance is 100–200 mg/kg.This study provides a theoretical basis for the application of PGLP in fish feed and for the analysis of the mechanism of nutrition and feed regulating fish flesh quality,which is of great significance.
基金financially supported by the earmarked fund for CARS(CARS-45)National Natural Science Foundation of China(32273144,32072985)National Key R&D Program of China(2019YFD0900200).
文摘Background Ochratoxin A(OTA)is a toxin widely found in aquafeed ingredients,and hypoxia is a common prob-lem in fish farming.In practice,aquatic animals tend to be more sensitive to hypoxia while feeds are contaminated with OTA,but no studies exist in this area.This research investigated the multiple biotoxicities of OTA and hypoxia combined on the liver of grass carp and explored the mitigating effect of curcumin(CUR).Methods A total of 720 healthy juvenile grass carp(11.06±0.05 g)were selected and assigned randomly to 4 experi-mental groups:control group(without OTA and CUR),1.2 mg/kg OTA group,400 mg/kg CUR group,and 1.2 mg/kg OTA+400 mg/kg CUR group with three replicates each for 60 d.Subsequently,32 fish were selected,divided into nor-moxia(18 fish)and hypoxia(18 fish)groups,and subjected to hypoxia stress for 96 h.Results CUR can attenuate histopathological damage caused by coming to OTA and hypoxia by reducing vacu-olation and nuclear excursion.The alleviation of this damage was associated with the attenuation of apoptosis in the mitochondrial pathway by decreasing the expression of the pro-apoptotic proteins Caspase 3,8,9,Bax,and Apaf1 while increasing the expression of the anti-apoptotic protein Bcl-2,and attenuation of endoplasmic reticulum stress(ERS)by reducing Grp78 expression and chop levels.This may be attributed to the fact that the addi-tion of CUR increased the levels of catalase(CAT)and glutathione reductase(GSH),increased antioxidant capacity,and ensured the proper functioning of respiratory chain complexes I and II,which in turn reduced the high produc-tion of reactive oxygen species(ROS),thus alleviating apoptosis and ERS.Conclusions In conclusion,our data demonstrate the effectiveness of CUR in attenuating liver injury caused by the combination of OTA and hypoxia.This study confirms the feasibility and efficacy of adding natural products to mitigate toxic damage to aquatic animals.
基金supported by the National Natural Science Foundation of China(32373162,31972824)Major Science and Technology Project of Hubei Province(2023BBA001),HZAU-AGIS Cooperation Fund(SZYJY2023006)China Agriculture Research System of MOF and MARA(CARS-46)。
文摘Teleost peripheral blood contains a remarkably high proportion of B cells,accounting for 15%-50%of circulating lymphocytes.However,their immune responses to bacterial infection are yet to be elucidated.In the present study,10×Genomics single-cell RNA sequencing(scRNA-seq)was employed to characterize the transcriptomic landscape of peripheral blood IgM^(+)B cells in grass carp(Ctenopharyngodon idella)following challenge with Aeromonas hydrophila,a major aquatic pathogen.Six transcriptionally distinct IgM^(+)B cell subpopulations were identified,including(im)mature B cells,innate B cells,proliferating B cells,IgD^(high)B cells,and two infection-induced subsets denoted as infectionⅠandⅡB cells.Bacterial infection altered the cellular heterogeneity of IgM^(+)B cells,triggered metabolic reprogramming in(im)mature and innate B cell subpopulations,and enhanced the immunological activation of circulating B cells.Notably,infectionⅠB cells demonstrated robust induction of interferonφ1(IFNφ1),a type I IFN,following A.hydrophila exposure.This induction was further validated through in vitro bacterial stimulation,indicating that teleost B cells actively contribute to innate antibacterial responses through IFN signaling.Additionally,the IgD^(high)B cell subpopulation remained consistently present in peripheral blood across both infected and uninfected states,pointing to a constitutive and likely mature phenotype.These findings significantly advance our understanding of the heterogeneity of peripheral blood IgM^(+)B cells and provide new insights into IgM^(+)B cell-mediated immune responses in teleost fish.
文摘The current investigation focuses on intertwined relationships of ecology and aquaculture for the benefit of farmers involved in fish farming practices.The study evaluated glucosinolate reduction in black,brown,and white mustard meals as fish feed ingredients for Indian Major Carps.Fish were fed with 10%mustard meal-supplemented diets in three forms:Raw(R),Anti-nutritional Rich(AR),and Anti-nutritional Lowered(AL),alongside a control group using floating feed.The three-month indoor experiment(September-November 2023)was conducted in FRP tanks with triplicate treatments.Blood analysis revealed compromised health in AR-fed carps,with reduced hemoglobin levels in rohu,catla and mrigal and elevated total leukocyte counts indicating inflammation in all the three carps studied here.Liver function was impaired in AR-fed fish,shown by increased alanine transaminase levels,highest in rohu followed by mrigal and catla.Histopathological examination of AR-fed carps liver tissue revealed necrotic spots,deformed hepatocytes,and significant vacuolation.In contrast,AL-fed fish demonstrated improved health parameters through Complete Blood Count analysis,liver function tests,and histo-pathological observations,suggesting successful reduction of anti-nutritional factors in the processed mustard meals.In near future,replacement of unprocessed seed meal with processed seed meal will lead to economic gains in fish farming.
文摘池塘养殖是我国主要的养殖模式,也是潜在的温室气体排放源。为探究典型草鱼养殖池塘二氧化碳(CO2)、甲烷(CH4)、氧化亚氮(N2O)通量特征及其驱动因素,以1龄(GC1)、2龄(GC2)和3龄(GC3)草鱼养殖池塘为对象,采用静态箱-气相色谱法原位监测气体通量,分析其排放强度及与环境因子的关系。结果显示,温室气体通量依次为GC3>GC2>GC1,GC3的CO2、CH4和N2O平均通量分别为42.30、13.31 mg/(m2·h)和567.25μg/(m2·h),所有池塘均为CH4的排放源。冗余分析表明,GC1气体通量主要受NO3-N和底泥温度影响,GC2以水温为主导,GC3则受底泥温度和溶解氧控制。直接排放系数分析显示,GC3池塘CO2、CH4和N2O排放系数分别为132.98、41.91和1.77 g/kg,均显著高于GC1和GC2(P<0.05)。单位面积增温潜势表现为GC3 (53.48 t CO2-eq/hm2)>GC2(31.84 t CO2-eq/hm2)>GC1 (6.54 t CO2-eq/hm2),差异显著(P<0.05)。单位产量温室气体排放强度在GC1、GC2和GC3中分别为0.26、1.05和1.95 t CO2-eq/t,差异显著(P<0.05)。养殖规格显著影响草鱼池塘温室气体排放强度,高温与大规格养殖加剧碳排放,建议通过调控养殖结构与环境因子,推动渔业碳中和。
基金This work was supported by National Natural Sciences Foundation of China (No. 39830300 )the Ministry of Education (No. 20065-14)
文摘The genomes of three groups of grass carp, namely the Xiangjiang River grass carp group （Xiangjiang group）, a one-generation artificially induced meio-gynogenetic grass carp group （meio-gynogenetic-1 group）, and a two-generation artificially induced meio-gynogenetic grass carp group （meio-gynogenetic-2 group）, were comparatively analyzed with microsatellite markers. Genetic polymorphism had been observed in the Xiangjiang group and most of the examined loci had more than two alleles. But the degree of genetic diversity was not very high. Although all the examined genetic loci in the analyzed individuals were in homozygous state, the genotypes of different individuals of the group were not identical in the meio-gynogenetic-1 group. In the meio-gynogenetic-2 group, not only the examined genetic loci of each individual were homozygous but also the genotypes of all the analyzed individuals of the group were the same. These results suggested that the examined meio-gynogenetic-2 group is a homozygous group and homozygous clone could be produced by continuous artificial induction of gynogenesis for two generations. It was found that the polymorphism existed not only at the allele level but also at the locus level; many alleles of the microsatellite loci and some of the microsatellite loci had been lost during the process of artificial gynogenesis. Therefore, both protection of the diversity of natural grass carp resource and selection of homozygous traits with desired economic genotypes are very important aspects for grass carp breeding.
基金Supported by National Freshwater Fish Industrial Technology System ProjectKey Discipline Construction Project of Shanghai(Y1101)Key Project of Science Committee in Shanghai(06DJ14003)~~
文摘[ Objective] The aim of this study was to investigate the growth and morphological characteristics of juvenile hybrids of grass carp. [Method] Three inbred generations of YR （Yangtze River stock ♀×Yangtze River stock ♂ ）, ZR （Zhujiang River stock ♀ ×Zhujiang River stock♂ ） and hybrids F1 （ Yangtze River stock ♀ × Zhujiang River stock ♂ ） were established, and their growth or morphological data were also measured. [ Result] The orders of body weight, standard length and absolute growth rate were F1 〉 ZR 〉 YR. No significant difference was found in body weight or standard length of 50 day-old generations （ P〉0. 05）, while there was an extremely significantly difference in those of 170 day-old generations （ P 〈0.01 ）. However, the absolute growth rate of F1 was 20.00% and 50.00% higher than that of ZR and YR respectively, and no significant difference was found between F1 and ZR （ P 〉 0.05）, but significant difference between F1 and YR （ P 〈 0.05）. F1 showed a significant hybrid vigor with rate of 20.09%. There was no significant difference among three inbred generations in standard length/total length （ P 〉 0.05）, while significant difference in head length/total length, body height/standard length and body width/standard length （ P 〈 0.05）, which indicated that F1 had the characteristics of shorter head, higher and wider body. [ Conclusion]F1 has advantages in growth performance and morphological characteristics.
