Whiteleg shrimp(Litopenaeus vannamei)is an economically important cultured species that is extensively cultured in China.However,there is the potential for further optimization of its survival and growth traits that a...Whiteleg shrimp(Litopenaeus vannamei)is an economically important cultured species that is extensively cultured in China.However,there is the potential for further optimization of its survival and growth traits that are key determinants of productivity in aquaculture.This study investigated the efficacy of hybridization,a genetic improvement technology leveraging hybrid vigor,as a strategy for enhancing these traits in L.vannamei.The study was conducted using a 4×4 complete diallel cross experiment involving four selected strains(5,8,9,and 10),with the aim of identifying potential crosses exhibiting hybrid vigor.The most suitable crosses were those between strains 8 and 9,where the mid-parent heterosis(H89)was 16.52%for survival and 18.93%for growth.Our findings revealed that most reciprocal hybrids displayed higher rates of survival than their inbred parents.Additionally,an age-dependent increase in the heterosis effect on weight was observed over mid-parents and single-parents in most hybrid offspring.These findings suggest that hybridization could be a promising approach to improving the survival and growth of whiteleg shrimp.Our crossing experiment has yielded novel genetic resources for shrimp breeding,ultimately enhancing the economic importance of whiteleg shrimp.展开更多
The precise assessment of the gonad status and gamete development level is an essential step in abalone breeding.However,traditional methods are damaging to the animals,causing the waste of a quality parent.Ultrasound...The precise assessment of the gonad status and gamete development level is an essential step in abalone breeding.However,traditional methods are damaging to the animals,causing the waste of a quality parent.Ultrasound imaging as a noninvasive technique is a candidate substitute.This study aimed to verify the application of ultrasonography to the assessment of abalone gonad condition.Pacific abalones(n=20)were randomly selected for ultrasonography,another six abalones in different gonad maturation stages(mature,between mature and immature,and immature)were also subjected to the same detection and histological analysis.Abalones(n=10)were induced to spawn,and the changes in the gonad index and the types of germ cells were determined before and after spawning.Thirty-six female abalones were selected and divided into a high-gonad index group(HGI)and a low-gonad index group(LGI)according to the gonad index determined by ultrasonography,and their reproductive performance was compared during the entire breeding process.There was no significant difference in gonad index or gonad relative average thickness(GRAT)obtained from ultrasonography and histological methods.The gonad index and GRAT measured by ultrasound images significantly decreased after spawning.After spawning,a minimal quantity of mature gametes remained in gonad tissue as reflected in histology images.In a reproductive trial,the HGI group showed comprehensive and overwhelming reproductive advantages compared to the LGI group in total fecundity,relative fecundity,fertilization rate,hatching rate,abnormality rate,and attachment rate.Ultrasonography was demonstrated to be useful as a noninvasive method to evaluate abalone gonad condition.The ultimate goal is to achieve tracing and monitoring the abalone reproductive cycle through the ultrasound technique.展开更多
The cost of reproduction is the core driver of life history evolution in animals.This paper demonstrates that the cumulative distance moved and the duration of movement of sexually immature abalones,Haliotis discus ha...The cost of reproduction is the core driver of life history evolution in animals.This paper demonstrates that the cumulative distance moved and the duration of movement of sexually immature abalones,Haliotis discus hannai,kept in various male and female groups,were significantly higher than those of sexually mature individuals,except when kept in mixed cultures of mature males and females.After mixed-culture,sexually mature males moved significantly further and for a longer duration than mature female abalones,and even more so than mature male abalones of any other group.Examination of the LC-MS metabolomics of mature males cultured with sexually mature females(AM)and those cultured with sexually immature females(JM)showed that cyclic adenosine monophosphate(cAMP)acted as a differential metabolic biomarker.After 24-h uninterrupted sampling,the concentration of 5-HT and the expression levels of the 5-HT2 and 5-HT6 receptors in AM were significantly higher than those in JM.After further injection of 5-HT2 and 5-HT6 receptor antagonists,the concentrations of cAMP and PKA rose again,but the cumulative movement duration and distance of male abalones decreased significantly,showing that 5-HT was involved in the regulation of movement behavior of male abalones through the 5-HT2 and 5-HT6 receptor-activated cAMP-PKA pathways.The results demonstrated a significant increase in the movement endurance of mature male abalones cultured with mature females,providing a theoretical basis for understanding the adaptive life history strategies of abalones and suggesting ways to protect diverse benthic resources for abalones during the reproductive stage.展开更多
Prostaglandin E2(PGE2)has been reported to be involved in reproduction as one of the most abundant and widely distributed prostaglandins in invertebrates.Regulating gonad development and gamete production in mollusks ...Prostaglandin E2(PGE2)has been reported to be involved in reproduction as one of the most abundant and widely distributed prostaglandins in invertebrates.Regulating gonad development and gamete production in mollusks can greatly assist artificial breeding,which is believed to promote the commercial benefits of various mollusk species.In the present study,the contents of PGE2 in the gonads of abalone at different developmental stages(maturing stage,ripe stage,and spawning stage)and reproduction states(before and after spawning)were measured.A higher PGE2 level was found in the gonads of abalones at the ripe stage than other stages,and the highest PGE2 level was detected in the ovaries of female H.diversicolor in the UV-stimulated group.Then the effects of PGE2 injection on the spawning efficiency were explored,and the gamete emission rates of female and male abalone were significantly increased after PGE2 injection.Through qRT-PCR and in situ hybridization assay,higher expression levels and wide distribution of phospholipase A2(PLA2),cyclooxygenase 2(COX2),prostaglandin E synthases(PGES2),and prostaglandin E2 receptor 4(EP4)in the gonads of H.diversicolor were observed after spawning.It is speculated that PGE2 may promote the reproductive cycle in both male and female H.diversicolor,although the regulation mechanism of PGE2 in female and male abalone might be different.The results will be useful for the application of PGE2 in the abalone aquaculture practices to increase the reproduction efficiency in future.展开更多
基金supported by grants from the Seed Industry Innovation and Industrialization Project in Fujian Province(2017FJSCZY02)。
文摘Whiteleg shrimp(Litopenaeus vannamei)is an economically important cultured species that is extensively cultured in China.However,there is the potential for further optimization of its survival and growth traits that are key determinants of productivity in aquaculture.This study investigated the efficacy of hybridization,a genetic improvement technology leveraging hybrid vigor,as a strategy for enhancing these traits in L.vannamei.The study was conducted using a 4×4 complete diallel cross experiment involving four selected strains(5,8,9,and 10),with the aim of identifying potential crosses exhibiting hybrid vigor.The most suitable crosses were those between strains 8 and 9,where the mid-parent heterosis(H89)was 16.52%for survival and 18.93%for growth.Our findings revealed that most reciprocal hybrids displayed higher rates of survival than their inbred parents.Additionally,an age-dependent increase in the heterosis effect on weight was observed over mid-parents and single-parents in most hybrid offspring.These findings suggest that hybridization could be a promising approach to improving the survival and growth of whiteleg shrimp.Our crossing experiment has yielded novel genetic resources for shrimp breeding,ultimately enhancing the economic importance of whiteleg shrimp.
基金supported by grants from National Natural Science Foundation of China(No.U22A20530)the Key S&T Program of Fujian Province(No.2020NZ08003)+1 种基金Seed Industry Innovation and Industrialization in Fujian Province(No.2021FJSCZY02)the Earmarked Fund for CARS(No.CARS-49).
文摘The precise assessment of the gonad status and gamete development level is an essential step in abalone breeding.However,traditional methods are damaging to the animals,causing the waste of a quality parent.Ultrasound imaging as a noninvasive technique is a candidate substitute.This study aimed to verify the application of ultrasonography to the assessment of abalone gonad condition.Pacific abalones(n=20)were randomly selected for ultrasonography,another six abalones in different gonad maturation stages(mature,between mature and immature,and immature)were also subjected to the same detection and histological analysis.Abalones(n=10)were induced to spawn,and the changes in the gonad index and the types of germ cells were determined before and after spawning.Thirty-six female abalones were selected and divided into a high-gonad index group(HGI)and a low-gonad index group(LGI)according to the gonad index determined by ultrasonography,and their reproductive performance was compared during the entire breeding process.There was no significant difference in gonad index or gonad relative average thickness(GRAT)obtained from ultrasonography and histological methods.The gonad index and GRAT measured by ultrasound images significantly decreased after spawning.After spawning,a minimal quantity of mature gametes remained in gonad tissue as reflected in histology images.In a reproductive trial,the HGI group showed comprehensive and overwhelming reproductive advantages compared to the LGI group in total fecundity,relative fecundity,fertilization rate,hatching rate,abnormality rate,and attachment rate.Ultrasonography was demonstrated to be useful as a noninvasive method to evaluate abalone gonad condition.The ultimate goal is to achieve tracing and monitoring the abalone reproductive cycle through the ultrasound technique.
基金This study was supported by grants from the National Natural Science Foundation of China(No.32273105)National Key R&D Program of China(2018YFD0901400),Key S&T Program of Fujian Province(No.2020NZ08003)+2 种基金Special Fund for Ocean and Fisheries of Xiamen(21CZY018HJ01)China Postdoctoral Science Foundation Grant[2019M650153,2021T140393]the Outstanding Postdoctoral Scholarship from the State Key Laboratory of Marine Environmental Science at Xiamen University.Thanks for the support from the Germplasm resources sharing platform of aquatic species in Fujian Province and XMU-MRB Abalone Research Center.
文摘The cost of reproduction is the core driver of life history evolution in animals.This paper demonstrates that the cumulative distance moved and the duration of movement of sexually immature abalones,Haliotis discus hannai,kept in various male and female groups,were significantly higher than those of sexually mature individuals,except when kept in mixed cultures of mature males and females.After mixed-culture,sexually mature males moved significantly further and for a longer duration than mature female abalones,and even more so than mature male abalones of any other group.Examination of the LC-MS metabolomics of mature males cultured with sexually mature females(AM)and those cultured with sexually immature females(JM)showed that cyclic adenosine monophosphate(cAMP)acted as a differential metabolic biomarker.After 24-h uninterrupted sampling,the concentration of 5-HT and the expression levels of the 5-HT2 and 5-HT6 receptors in AM were significantly higher than those in JM.After further injection of 5-HT2 and 5-HT6 receptor antagonists,the concentrations of cAMP and PKA rose again,but the cumulative movement duration and distance of male abalones decreased significantly,showing that 5-HT was involved in the regulation of movement behavior of male abalones through the 5-HT2 and 5-HT6 receptor-activated cAMP-PKA pathways.The results demonstrated a significant increase in the movement endurance of mature male abalones cultured with mature females,providing a theoretical basis for understanding the adaptive life history strategies of abalones and suggesting ways to protect diverse benthic resources for abalones during the reproductive stage.
基金supported by grants from National Natural Science Foundation of China (No.31860728 and 32172961)Special Fund for Ocean and Fisheries of Xiamen (No.21CZY018HJ01).
文摘Prostaglandin E2(PGE2)has been reported to be involved in reproduction as one of the most abundant and widely distributed prostaglandins in invertebrates.Regulating gonad development and gamete production in mollusks can greatly assist artificial breeding,which is believed to promote the commercial benefits of various mollusk species.In the present study,the contents of PGE2 in the gonads of abalone at different developmental stages(maturing stage,ripe stage,and spawning stage)and reproduction states(before and after spawning)were measured.A higher PGE2 level was found in the gonads of abalones at the ripe stage than other stages,and the highest PGE2 level was detected in the ovaries of female H.diversicolor in the UV-stimulated group.Then the effects of PGE2 injection on the spawning efficiency were explored,and the gamete emission rates of female and male abalone were significantly increased after PGE2 injection.Through qRT-PCR and in situ hybridization assay,higher expression levels and wide distribution of phospholipase A2(PLA2),cyclooxygenase 2(COX2),prostaglandin E synthases(PGES2),and prostaglandin E2 receptor 4(EP4)in the gonads of H.diversicolor were observed after spawning.It is speculated that PGE2 may promote the reproductive cycle in both male and female H.diversicolor,although the regulation mechanism of PGE2 in female and male abalone might be different.The results will be useful for the application of PGE2 in the abalone aquaculture practices to increase the reproduction efficiency in future.
