The small yellow croaker Larimichthys polyactis is an economically important marine fish in Northeast Asia.Currently,its natural resources are threatened by overfishing and environmental pollution.Therefore,research o...The small yellow croaker Larimichthys polyactis is an economically important marine fish in Northeast Asia.Currently,its natural resources are threatened by overfishing and environmental pollution.Therefore,research on the reproductive system of the fish is crucial.Here,we studied the testis development and ultrastructural features of spermatogenesis in cultured L.polyactis using anatomical,histological,and ultrastructural techniques.A pair of testes,consisting of a central sperm duct and radial seminiferous lobules,were observed.The reproduction cycle of testes can be divided into stages I–VI.March to May was confirmed as the breeding season for male L.polyactis,while April is the ideal period for artificial breeding.The male L.polyactis can attain sexual maturity within 1 year.The spermatogenesis of L.polyactis comprised spermatogonium,spermatocyte,spermatid,and mature spermatozoon.The morphology of spermatogenic cells changed obviously during spermiogenesis,including nuclear shaping,midpiece and flagellum formation.The mature sperms consist of an ellipsoidal head,a short midpiece,and a long flagellum.The anterior of the head with a kidney-shaped nucleus can be distinguished.The midpiece is located posterior to the head and includes four to six spherical mitochondria.The flagellum has irregular lateral fins.The testis of L.polyactis is an unrestricted lobular type,with cystic spermatogenesis,type II spermiogenesis,and type II spermatozoa.These features are highly similar to those of other Sciaenid species.Our findings provide useful insights into the mechanism underlying testis development and spermatogenesis of L.polyactis,which can facilitate the artificial breeding of this species.展开更多
Length frequency data of small yellow croaker （Larimichthys polyactis） were acquired from the survey vessel in May, July, September and December, 2011 in Haizhou Bay of China. In this study, 921 fish individuals wer...Length frequency data of small yellow croaker （Larimichthys polyactis） were acquired from the survey vessel in May, July, September and December, 2011 in Haizhou Bay of China. In this study, 921 fish individuals were analyzed for the estimation of growth and mortality parameters. Between length and weight, the power coefficient b was 2.7321, 2.9703, 3.0418 and 2.7252 for the 4 surveying months, respectively. The estimated von Bertalanffy growth function parameters were 230mm （L∞） and 0.26yr-1 （K） as were calculated with ELEFAN method equipped in FiSAT computer package. With length-converted catch curve analysis, the total mortality rate （Z） and its 95% confidence interval were 2.16 （1.69-2.64） yr-1, 0.59 （0.15-1.04） yr-1, 1.16 （0.80-1.52） yrl and 0.96 （0.70-1.23） yr1 for the 4 surveying months, respectively, with the pooled data the value was 1.15 （0.81-1.48） yr1. The natural mor- tality rate （M） was 0.516 yr 1 as was calculated with Pauly＇s equation （the annual average sea water temperature was 11 ℃）. Therefore, fish mortality rate was 0.634 yrz. The yield-per-recruit analysis indicated that when tc was 1, Fmax, was 0.7 and F01 was 0.55. Cur- rently, the age at first capture is about 1 year and Fcurrent was 0.634. Therefore, Fcurrent was larger than F0.1 and less than Fmax. This indicates that current fish mortality is at a dangerously high level. With Gulland method, the biological reference point for fishery （Fopt） was estimated as 0.516 yr1, lower than current fish mortality. Accordingly, reducing catch in the region was strongly recom- mended.展开更多
The growth hormone gene (GH) affects animal growth and is a potential target for genetic studies of variation related to growth traits. In this study, we analyzed single nucleotide polymorphisms (SNPs) in GH intron re...The growth hormone gene (GH) affects animal growth and is a potential target for genetic studies of variation related to growth traits. In this study, we analyzed single nucleotide polymorphisms (SNPs) in GH intron regions and their associations with growth traits in large yellow croaker, Larimichthys crocea, from Zhejiang and Fujian stocks. The results of PCR-single strand conformation polymorphism showed two haplotypes of intron 1, named AA and AB genotypes, in Zhejiang stock. AB exhibited an SNP at position 196 (G A) that was negatively correlated with body height and positively correlated with standard length/body height (P 0.05). Two different genotypes, CC and CD, were identified in intron 2 in Fujian stock, with CD showing an SNP at position 692 (T C). The CD genotype had a significantly positive correlation with both weight and total length (P 0.01). These basic data highlight the potential for using GH as a genetic marker of fish growth in marker assisted selection.展开更多
We estimated the reproductive success of adult brood fish and the heritability of growthrelated traits for large yellow croaker （Larimichthys crocea）. We created two independent full-factorial cross groups （1 and 2...We estimated the reproductive success of adult brood fish and the heritability of growthrelated traits for large yellow croaker （Larimichthys crocea）. We created two independent full-factorial cross groups （1 and 2） by crossing 4 malesx4 females and 4 males^3 females, respectively. We measured the body weight （BW）, body length （BL）, and body height （BH） of 281 individuals from group 1 and 318 individuals from group 2 at 20 months post hatch （harvest age）. We also collected a tissue sample from each individual. The parents and offspring were genotyped using six polymorphic mierosatellites. Of the 599 offspring, 99.2% were assigned to a single pair of parents. In both groups, some parent pairs produced a large number of offsprings while other pairs did not produce any offspring. The genetic diversity and putative No were lower in the offsprings than in the parents in both groups. The heritability estimates at 20-month age were 0.13±0.10 for BW, 0.19±0.13 for BL, and 0.09±0.06 for BH. The genetic and phenotype correlation between BW, BL, and BH was close to 1. The results provide basic information for selective breeding and further genetic characterization of large yellow croaker.展开更多
Host-pathogen interactions are highly complex,involving large dynamic changes in gene expression during infection. These interactions are fundamental to understanding anti-infection immunity of hosts, as well as the p...Host-pathogen interactions are highly complex,involving large dynamic changes in gene expression during infection. These interactions are fundamental to understanding anti-infection immunity of hosts, as well as the pathogenesis of pathogens. For bacterial pathogens interacting with animal hosts, timeresolved dual RNA-seq of infected tissue is difficult to perform due to low pathogen load in infected tissue. In this study, an acute infection model of Larimichthys crocea infected by Pseudomonas plecoglossicida was established. The spleens of infected fish exhibited typical symptoms, with a maximum bacterial load at two days post-injection(dpi). Time-resolved dual RNA-seq of infected spleens was successfully applied to study hostpathogen interactions between L. crocea and P.plecoglossicida. The spleens of infected L. crocea were subjected to dual RNA-seq, and transcriptome data were compared with those of noninfected spleens or in vitro cultured bacteria. Results showed that pathogen-host interactions were highly dynamically regulated, with corresponding fluctuations in host and pathogen transcriptomes during infection. The expression levels of many immunogenes involved in cytokine-cytokine receptor,Toll-like receptor signaling, and other immunerelated pathways were significantly up-regulated during the infection period. Furthermore, metabolic processes and the use of oxygen in L. crocea were strongly affected by P. plecoglossicida infection. The WGCNA results showed that the metabolic process was strongly related to the entire immune process.For P. plecoglossicida, the expression levels of motility-related genes and flagellum assemblyrelated genes were significantly up-regulated. The results of this study may help to elucidate the interactions between L. crocea and P.plecoglossicida.展开更多
Oxygen is an essential molecule for animal respiration,growth,and survival.Unlike in terrestrial environments,contamination and climate change have led to the frequent occurrence of hypoxia in aquatic environments,thu...Oxygen is an essential molecule for animal respiration,growth,and survival.Unlike in terrestrial environments,contamination and climate change have led to the frequent occurrence of hypoxia in aquatic environments,thus impacting aquatic animal survival.However,the adaptative mechanisms underlying fish responses to environmental hypoxia remain largely unknown.Here,we used large yellow croaker(Larimichthys crocea)and large yellow croaker fry(LYCF)cells to investigate the roles of the Hif-1α/Hsf1/Hsp70 signaling pathway in the regulation of cellular redox homeostasis,and apoptosis.We confirmed that hypoxia induced the expression of Hif-1α,Hsf1,and Hsp70 in vivo and in vitro.Genetic Hsp70 knockdown/overexpression indicated that Hsp70 was required for maintaining redox homeostasis and resisting oxidative stress in LYCF cells under hypoxic stress.Hsp70 inhibited caspase-dependent intrinsic apoptosis by maintaining normal mitochondrial membrane potential,enhancing Bcl-2 mRNA and protein expression,inhibiting Bax and caspase3 mRNA expression,and suppressing caspase-3 and caspase-9 activation.Hsp70 suppressed caspaseindependent intrinsic apoptosis by inhibiting nuclear translocation of apoptosis-inducing factor(AIF)and disturbed extrinsic apoptosis by inactivating caspase-8.Genetic knockdown/overexpression of Hif-1αand dual-luciferase reporter assay indicated that Hif-1αactivated the Hsf1 DNA promoter and enhanced Hsf1 mRNA transcription.Hsf1 enhanced Hsp70 mRNA transcription in a similar manner.In summary,the Hif-1α/Hsf1/Hsp70 signaling pathway plays an important role in regulating redox homeostasis and anti-apoptosis in L.crocea under hypoxic stress.展开更多
An （AC）n-microsatellite-enriched library for Larimichthys crocea was constructed in this study. Primers for fifty simple sequence repeat （SSR） loci were synthesized and genotyped on 30 L. crocea individuals from G...An （AC）n-microsatellite-enriched library for Larimichthys crocea was constructed in this study. Primers for fifty simple sequence repeat （SSR） loci were synthesized and genotyped on 30 L. crocea individuals from Guanjingyang wild population （WP） in Fujian Province and 38 individuals from Ningbo cultured population （CP） in Zhejiang Province. Only 21 loci were successfully amplified and polymorphic in two populations. In WP, the observed heterozygosity （Ho） ranged from 0.233 to 0.900 and the expected heterozygosity （HE） ranged from 0.326 to 0.893, with an average of 7.8 alleles/locus, the polymorphism information content （PIC） ranged from 0.283 to 0.866 （mean 0.731）. In CP, the Ho ranged from 0.189 to 0.892 and the HE ranged from 0.333 to 0.800, with an average of 4.4 alleles/locus. The probability test showed significant departures from HWE in 9 and 2 of the 21 loci in WP and in CP, respectively. Deficiency of heterozygotes at four loci showed the presence of null alleles （P 〈0.01）. The PIC of 20 microsatellite loci in WP were greater than 0.50. Overall, these novel markers are potentially useful for the study of population genetics, construction of genetic linkage and quantitative trait loci maps in large yellow croaker.展开更多
Large yellow croaker(Larimichthys crocea), one of the most important marine fish species in China, can change its abdominal skin color when it is shifted from light to dark or from dark to light, providing us an oppor...Large yellow croaker(Larimichthys crocea), one of the most important marine fish species in China, can change its abdominal skin color when it is shifted from light to dark or from dark to light, providing us an opportunity of investigating the molecular responding mechanism of teleost in light stress. The gene expression profile of fish under light stress is rarely documented. In this research, the transcriptome profiles of the abdominal skin of L. crocea exposed to light or dark for 0 h, 0.5 h and 2 h were produced by next-generation sequencing(NGS). The cluster results demonstrated that stress period, rather than light intensity(e.g., light or dark), is the major influencing factor. Differently expressed genes(DEGs) were identified between 0 h and 0.5 h groups, between 0 h and 2 h groups, between 0.5 h light and 0.5 h dark, and between 2 h light and 2 h dark, respectively. The gene ontology(GO) and Kyoto Encyclopedia of Genes and Genomes(KEGG) annotation revealed that the genes relating to immunity, energy metabolism, and cytoskeletal protein binding were significantly enriched. The detailed analysis of transcriptome profiles also revealed regular gene expression trends, indicating that the elaborate gene regulation networks underlined the molecular responses of the fish to light stress. This transcriptome analysis suggested that systematic and complicated regulatory cascades were functionally activated in response to external stress, and coloration change caused by light stress was mainly attributed to the change in the density of chromatophores for L. crocea. This study also provided valuable information for skin coloration or light stress research on other marine fish species.展开更多
Toll-like receptor 21(TLR21) is a non-mammalian type TLR, and plays an important role in innate immune response in fish. In this paper, the full-length cDNA sequence of TLR21 gene was identified and characterized from...Toll-like receptor 21(TLR21) is a non-mammalian type TLR, and plays an important role in innate immune response in fish. In this paper, the full-length cDNA sequence of TLR21 gene was identified and characterized from large yellow croaker, Larimichthys crocea and was termed as LcTLR21. It consists of 3365 bp, including a 5'-terminal untranslated region(UTR) of 97 bp, a 3'-terminal UTR of 331 bp, and an open reading frame(ORF) of 2937 bp encoding a polypeptide of 978 amino acid residues. The deduced LcTLR21 contains a signal peptide domain at N-terminal, 12 leucine-rich repeats(LRRs) at the extracellular region, a transmembrane domain and a cytoplasmic toll-interleukin-1 receptor(TIR) domain at the C-terminal. Subcellular localization analysis revealed that the LcTLR21-GFP was constitutively expressed in cytoplasm. Tissue expression analysis indicated that LcTLR21 gene broadly expressed in most of the examined tissues, with the most predominant abundance in spleen, followed by head-kidney and liver, while the weakest expression was detected in brain. The expression level of LcTLR21 after LPS, poly I:C and Vibrio parahaemolyticus challenges was investigated in spleen, head-kidney and liver. LcTLR21 gene transcripts increased significantly in all examined tissues after the challenges, and the highest expression level was detected in liver at 24 h after poly I:C stimulation(P <0.05), suggesting that LcTLR21 might play a crucial role in fish resistance to viral and bacterial infections.展开更多
Temporal changes in biological characteristics of small yellow croaker Larimichthys polyactis in the Yellow Sea were examined for the period of 1960–2008. The body size and age of small yellow croaker decreased subst...Temporal changes in biological characteristics of small yellow croaker Larimichthys polyactis in the Yellow Sea were examined for the period of 1960–2008. The body size and age of small yellow croaker decreased substantially, in particular, average length of fish in 2008 was reduced by ~85% than those occurring in 1985, and at that time ~93% of the total catch was dominated by one-year-old individuals. Correspondingly, growth parameters also varied significantly over the years, i.e., k（growth coefficient） and t_0（zero-length age） gradually increased from 0.26 and –0.58 year in 1960 to 0.56 and –0.25 year in 2008, respectively. Although, L∞（body length）sharply decreased from 34.21 cm in 1960 to 24.06 cm in 2008, and t_r（inflexion age） decreased from 3.78 year in1960 to 1.61 year in 2008. There was a great increase both in natural mortality coefficient and fishing mortality coefficient. However, according to the gray correlation analysis, changes in the biological characteristics of small yellow croaker were induced by different stressors ranked as： fishing vessel power〉feeding grade〉sea surface temperature. This study suggests that the active fishery management measures for biological characters of fish populations should be considered.展开更多
KIF3A and KIF3B are two N-terminal motor proteins belonging to the kinesin-II superfamily that play essential roles in spermiogenesis.To understand the roles played by KIF3 A/3B during spermatogenesis of large yellow ...KIF3A and KIF3B are two N-terminal motor proteins belonging to the kinesin-II superfamily that play essential roles in spermiogenesis.To understand the roles played by KIF3 A/3B during spermatogenesis of large yellow croaker Larimichthys crocea,we studied the testis characteristics at different developmental stages of L.crocea,and determined the spatiotemporal expression patterns of kif3a and kif3b during spermiogenesis.Quantitative real-time PCR(qR T-PCR)showed that the overall trends of kif3 a/3 b m RNA abundance during testis development are similar.From stage Ⅱ to stage V,kif3a/3b m RNA abundances first increased and then fell after reaching a peak at stage IV.Interestingly,the m RNA abundances of both genes at stage V were higher than those at stages Ⅱ and Ⅲ.In addition,it is worth of noting that kif3 b m RNA abundance was higher than that of kif3a at all stages.Fluorescence in situ hybridization results revealed that kif3a/3b m RNA abundance dynamics were consistent with the migration of mitochondria,the deformation of nucleus,and the formation of tail.The m RNA hybridization signals of both genes first appeared either around the nuclear periphery or on the side of the nuclei,then appeared at one side of nuclei,and finally were mainly on the tail during spermiogenesis.Our findings contributed to better understanding the molecular mechanisms of spermiogenesis in fish;and suggested that KIF3A and KIF3B may participate in the intracellular transport of mitochondria,nuclear deformation,and the formation of tail during the spermiogenesis in L.crocea.展开更多
基金the NSFC-Zhejiang Joint Fund for the Integration of Industrialization and Informatization(No.U1809212)the Scientific and Technical Project of Zhejiang Province(Nos.2021C02055,2017C02013)+2 种基金the National Natural Science Foundation of China(No.31272642)Healthy Aquaculture,the K.C.Wong Magna Fund in Ningbo Universitythe Collaborative Innovation Center for Zhejiang Marine High-Efficiency。
文摘The small yellow croaker Larimichthys polyactis is an economically important marine fish in Northeast Asia.Currently,its natural resources are threatened by overfishing and environmental pollution.Therefore,research on the reproductive system of the fish is crucial.Here,we studied the testis development and ultrastructural features of spermatogenesis in cultured L.polyactis using anatomical,histological,and ultrastructural techniques.A pair of testes,consisting of a central sperm duct and radial seminiferous lobules,were observed.The reproduction cycle of testes can be divided into stages I–VI.March to May was confirmed as the breeding season for male L.polyactis,while April is the ideal period for artificial breeding.The male L.polyactis can attain sexual maturity within 1 year.The spermatogenesis of L.polyactis comprised spermatogonium,spermatocyte,spermatid,and mature spermatozoon.The morphology of spermatogenic cells changed obviously during spermiogenesis,including nuclear shaping,midpiece and flagellum formation.The mature sperms consist of an ellipsoidal head,a short midpiece,and a long flagellum.The anterior of the head with a kidney-shaped nucleus can be distinguished.The midpiece is located posterior to the head and includes four to six spherical mitochondria.The flagellum has irregular lateral fins.The testis of L.polyactis is an unrestricted lobular type,with cystic spermatogenesis,type II spermiogenesis,and type II spermatozoa.These features are highly similar to those of other Sciaenid species.Our findings provide useful insights into the mechanism underlying testis development and spermatogenesis of L.polyactis,which can facilitate the artificial breeding of this species.
基金supported by the Fundamental Research Funds for Central Universities (Grant No. 201022001)
文摘Length frequency data of small yellow croaker （Larimichthys polyactis） were acquired from the survey vessel in May, July, September and December, 2011 in Haizhou Bay of China. In this study, 921 fish individuals were analyzed for the estimation of growth and mortality parameters. Between length and weight, the power coefficient b was 2.7321, 2.9703, 3.0418 and 2.7252 for the 4 surveying months, respectively. The estimated von Bertalanffy growth function parameters were 230mm （L∞） and 0.26yr-1 （K） as were calculated with ELEFAN method equipped in FiSAT computer package. With length-converted catch curve analysis, the total mortality rate （Z） and its 95% confidence interval were 2.16 （1.69-2.64） yr-1, 0.59 （0.15-1.04） yr-1, 1.16 （0.80-1.52） yrl and 0.96 （0.70-1.23） yr1 for the 4 surveying months, respectively, with the pooled data the value was 1.15 （0.81-1.48） yr1. The natural mor- tality rate （M） was 0.516 yr 1 as was calculated with Pauly＇s equation （the annual average sea water temperature was 11 ℃）. Therefore, fish mortality rate was 0.634 yrz. The yield-per-recruit analysis indicated that when tc was 1, Fmax, was 0.7 and F01 was 0.55. Cur- rently, the age at first capture is about 1 year and Fcurrent was 0.634. Therefore, Fcurrent was larger than F0.1 and less than Fmax. This indicates that current fish mortality is at a dangerously high level. With Gulland method, the biological reference point for fishery （Fopt） was estimated as 0.516 yr1, lower than current fish mortality. Accordingly, reducing catch in the region was strongly recom- mended.
基金Supported by the National Basic Research Program of China(973Program)(No.2010CB126304)the Special Fund for Agro-scientific Research in the Public Interest(No.200903046)the Project from the Ministry of Science and Technology of China(No.2006DKA30470017)
文摘The growth hormone gene (GH) affects animal growth and is a potential target for genetic studies of variation related to growth traits. In this study, we analyzed single nucleotide polymorphisms (SNPs) in GH intron regions and their associations with growth traits in large yellow croaker, Larimichthys crocea, from Zhejiang and Fujian stocks. The results of PCR-single strand conformation polymorphism showed two haplotypes of intron 1, named AA and AB genotypes, in Zhejiang stock. AB exhibited an SNP at position 196 (G A) that was negatively correlated with body height and positively correlated with standard length/body height (P 0.05). Two different genotypes, CC and CD, were identified in intron 2 in Fujian stock, with CD showing an SNP at position 692 (T C). The CD genotype had a significantly positive correlation with both weight and total length (P 0.01). These basic data highlight the potential for using GH as a genetic marker of fish growth in marker assisted selection.
基金Supported by the Special Fund for Agro-Scientific Research in the Public Interest (No. 200903029-4)Key Project of Science and Technology Department of Fujian Province (No. 2010N0021)the Foundation for Young Professors of Jimei University (No. 2009C002)
文摘We estimated the reproductive success of adult brood fish and the heritability of growthrelated traits for large yellow croaker （Larimichthys crocea）. We created two independent full-factorial cross groups （1 and 2） by crossing 4 malesx4 females and 4 males^3 females, respectively. We measured the body weight （BW）, body length （BL）, and body height （BH） of 281 individuals from group 1 and 318 individuals from group 2 at 20 months post hatch （harvest age）. We also collected a tissue sample from each individual. The parents and offspring were genotyped using six polymorphic mierosatellites. Of the 599 offspring, 99.2% were assigned to a single pair of parents. In both groups, some parent pairs produced a large number of offsprings while other pairs did not produce any offspring. The genetic diversity and putative No were lower in the offsprings than in the parents in both groups. The heritability estimates at 20-month age were 0.13±0.10 for BW, 0.19±0.13 for BL, and 0.09±0.06 for BH. The genetic and phenotype correlation between BW, BL, and BH was close to 1. The results provide basic information for selective breeding and further genetic characterization of large yellow croaker.
基金the National Natural Science Foundation of China(31672694,31972836)Fujian Provincial Special Fund for Marine and Fishery Protection and Development(MCZ[2019]062)。
文摘Host-pathogen interactions are highly complex,involving large dynamic changes in gene expression during infection. These interactions are fundamental to understanding anti-infection immunity of hosts, as well as the pathogenesis of pathogens. For bacterial pathogens interacting with animal hosts, timeresolved dual RNA-seq of infected tissue is difficult to perform due to low pathogen load in infected tissue. In this study, an acute infection model of Larimichthys crocea infected by Pseudomonas plecoglossicida was established. The spleens of infected fish exhibited typical symptoms, with a maximum bacterial load at two days post-injection(dpi). Time-resolved dual RNA-seq of infected spleens was successfully applied to study hostpathogen interactions between L. crocea and P.plecoglossicida. The spleens of infected L. crocea were subjected to dual RNA-seq, and transcriptome data were compared with those of noninfected spleens or in vitro cultured bacteria. Results showed that pathogen-host interactions were highly dynamically regulated, with corresponding fluctuations in host and pathogen transcriptomes during infection. The expression levels of many immunogenes involved in cytokine-cytokine receptor,Toll-like receptor signaling, and other immunerelated pathways were significantly up-regulated during the infection period. Furthermore, metabolic processes and the use of oxygen in L. crocea were strongly affected by P. plecoglossicida infection. The WGCNA results showed that the metabolic process was strongly related to the entire immune process.For P. plecoglossicida, the expression levels of motility-related genes and flagellum assemblyrelated genes were significantly up-regulated. The results of this study may help to elucidate the interactions between L. crocea and P.plecoglossicida.
基金This work was supported by the National Key Research and Development Program of China(2018YFC1406300)NSFC-Zhejiang Joint Fund for the Integration of Industrialization and Informatization(U1809212)+4 种基金Scientific and Technical Project of Zhejiang Province(2021C02069-1,2016C02055-7)Scientific and Technical Project of Ningbo City(2021Z002,2015C110005)Ningbo Science and Technology Plan Projects(2018A610228)Teaching and Research Project of Ningbo University(XYL19023)Collaborative Innovation Center for Zhejiang Marine High-Efficiency and Healthy Aquaculture,K.C.Wong Magna Fund in Ningbo University。
文摘Oxygen is an essential molecule for animal respiration,growth,and survival.Unlike in terrestrial environments,contamination and climate change have led to the frequent occurrence of hypoxia in aquatic environments,thus impacting aquatic animal survival.However,the adaptative mechanisms underlying fish responses to environmental hypoxia remain largely unknown.Here,we used large yellow croaker(Larimichthys crocea)and large yellow croaker fry(LYCF)cells to investigate the roles of the Hif-1α/Hsf1/Hsp70 signaling pathway in the regulation of cellular redox homeostasis,and apoptosis.We confirmed that hypoxia induced the expression of Hif-1α,Hsf1,and Hsp70 in vivo and in vitro.Genetic Hsp70 knockdown/overexpression indicated that Hsp70 was required for maintaining redox homeostasis and resisting oxidative stress in LYCF cells under hypoxic stress.Hsp70 inhibited caspase-dependent intrinsic apoptosis by maintaining normal mitochondrial membrane potential,enhancing Bcl-2 mRNA and protein expression,inhibiting Bax and caspase3 mRNA expression,and suppressing caspase-3 and caspase-9 activation.Hsp70 suppressed caspaseindependent intrinsic apoptosis by inhibiting nuclear translocation of apoptosis-inducing factor(AIF)and disturbed extrinsic apoptosis by inactivating caspase-8.Genetic knockdown/overexpression of Hif-1αand dual-luciferase reporter assay indicated that Hif-1αactivated the Hsf1 DNA promoter and enhanced Hsf1 mRNA transcription.Hsf1 enhanced Hsp70 mRNA transcription in a similar manner.In summary,the Hif-1α/Hsf1/Hsp70 signaling pathway plays an important role in regulating redox homeostasis and anti-apoptosis in L.crocea under hypoxic stress.
基金The Special Fund for Agro-Scientific Research in the Public Interest under contract No.200903046-5the National High Technology Research and Development Program of China(863program)under contract No.2006AA10A405+1 种基金the National Natural Science Foundation of China under contract No.30771663the Foundation for Innovation Research Team of Jimei University,China under contract No.2006A001
文摘An （AC）n-microsatellite-enriched library for Larimichthys crocea was constructed in this study. Primers for fifty simple sequence repeat （SSR） loci were synthesized and genotyped on 30 L. crocea individuals from Guanjingyang wild population （WP） in Fujian Province and 38 individuals from Ningbo cultured population （CP） in Zhejiang Province. Only 21 loci were successfully amplified and polymorphic in two populations. In WP, the observed heterozygosity （Ho） ranged from 0.233 to 0.900 and the expected heterozygosity （HE） ranged from 0.326 to 0.893, with an average of 7.8 alleles/locus, the polymorphism information content （PIC） ranged from 0.283 to 0.866 （mean 0.731）. In CP, the Ho ranged from 0.189 to 0.892 and the HE ranged from 0.333 to 0.800, with an average of 4.4 alleles/locus. The probability test showed significant departures from HWE in 9 and 2 of the 21 loci in WP and in CP, respectively. Deficiency of heterozygotes at four loci showed the presence of null alleles （P 〈0.01）. The PIC of 20 microsatellite loci in WP were greater than 0.50. Overall, these novel markers are potentially useful for the study of population genetics, construction of genetic linkage and quantitative trait loci maps in large yellow croaker.
基金supported by grants from the National Natural Science Foundation of China (No.U1205122)Key projects of the Xiamen Southern Ocean Research Center (14GZY70NF34)+1 种基金the Natural Science Foundation of Fujian Province (No.2015J05069)‘Li ShangDa’ Foundation and Innovation Research Team Foundation of Jimei University (No.2010A02)
文摘Large yellow croaker(Larimichthys crocea), one of the most important marine fish species in China, can change its abdominal skin color when it is shifted from light to dark or from dark to light, providing us an opportunity of investigating the molecular responding mechanism of teleost in light stress. The gene expression profile of fish under light stress is rarely documented. In this research, the transcriptome profiles of the abdominal skin of L. crocea exposed to light or dark for 0 h, 0.5 h and 2 h were produced by next-generation sequencing(NGS). The cluster results demonstrated that stress period, rather than light intensity(e.g., light or dark), is the major influencing factor. Differently expressed genes(DEGs) were identified between 0 h and 0.5 h groups, between 0 h and 2 h groups, between 0.5 h light and 0.5 h dark, and between 2 h light and 2 h dark, respectively. The gene ontology(GO) and Kyoto Encyclopedia of Genes and Genomes(KEGG) annotation revealed that the genes relating to immunity, energy metabolism, and cytoskeletal protein binding were significantly enriched. The detailed analysis of transcriptome profiles also revealed regular gene expression trends, indicating that the elaborate gene regulation networks underlined the molecular responses of the fish to light stress. This transcriptome analysis suggested that systematic and complicated regulatory cascades were functionally activated in response to external stress, and coloration change caused by light stress was mainly attributed to the change in the density of chromatophores for L. crocea. This study also provided valuable information for skin coloration or light stress research on other marine fish species.
基金funded by the Qingdao National Laboratory for Marine Science and Technology to Cuiluan Yaothe Natural Science Foundation of Fujian (No.2018J01454)the National Natural Science Foundation of China (Nos.31101882 and 41276178)
文摘Toll-like receptor 21(TLR21) is a non-mammalian type TLR, and plays an important role in innate immune response in fish. In this paper, the full-length cDNA sequence of TLR21 gene was identified and characterized from large yellow croaker, Larimichthys crocea and was termed as LcTLR21. It consists of 3365 bp, including a 5'-terminal untranslated region(UTR) of 97 bp, a 3'-terminal UTR of 331 bp, and an open reading frame(ORF) of 2937 bp encoding a polypeptide of 978 amino acid residues. The deduced LcTLR21 contains a signal peptide domain at N-terminal, 12 leucine-rich repeats(LRRs) at the extracellular region, a transmembrane domain and a cytoplasmic toll-interleukin-1 receptor(TIR) domain at the C-terminal. Subcellular localization analysis revealed that the LcTLR21-GFP was constitutively expressed in cytoplasm. Tissue expression analysis indicated that LcTLR21 gene broadly expressed in most of the examined tissues, with the most predominant abundance in spleen, followed by head-kidney and liver, while the weakest expression was detected in brain. The expression level of LcTLR21 after LPS, poly I:C and Vibrio parahaemolyticus challenges was investigated in spleen, head-kidney and liver. LcTLR21 gene transcripts increased significantly in all examined tissues after the challenges, and the highest expression level was detected in liver at 24 h after poly I:C stimulation(P <0.05), suggesting that LcTLR21 might play a crucial role in fish resistance to viral and bacterial infections.
基金The National Basic Research Program(973 Program)of China under contract No.2015CB453303the Aoshan Scientific and Technical Innovation Program under contract No.2015ASKJ02-05the Taishan Scholar Project Special Fund
文摘Temporal changes in biological characteristics of small yellow croaker Larimichthys polyactis in the Yellow Sea were examined for the period of 1960–2008. The body size and age of small yellow croaker decreased substantially, in particular, average length of fish in 2008 was reduced by ~85% than those occurring in 1985, and at that time ~93% of the total catch was dominated by one-year-old individuals. Correspondingly, growth parameters also varied significantly over the years, i.e., k（growth coefficient） and t_0（zero-length age） gradually increased from 0.26 and –0.58 year in 1960 to 0.56 and –0.25 year in 2008, respectively. Although, L∞（body length）sharply decreased from 34.21 cm in 1960 to 24.06 cm in 2008, and t_r（inflexion age） decreased from 3.78 year in1960 to 1.61 year in 2008. There was a great increase both in natural mortality coefficient and fishing mortality coefficient. However, according to the gray correlation analysis, changes in the biological characteristics of small yellow croaker were induced by different stressors ranked as： fishing vessel power〉feeding grade〉sea surface temperature. This study suggests that the active fishery management measures for biological characters of fish populations should be considered.
基金financially supported by the Scientific and Technical Project of Zhejiang Province (Nos. 2016C02055-7, LY18C190007)the Ningbo Natural Science Foundation (No. 2016A610081)+3 种基金the Scientific and Technical Project of Ningbo (No. 2015C110005)the National Natural Science Foundation of China (No. 31602140)the Collaborative Innovation Center for Zhejiang Marine High-efficiency and Healthy Aquaculturethe K. C. Wong Magna Fund in Ningbo University
文摘KIF3A and KIF3B are two N-terminal motor proteins belonging to the kinesin-II superfamily that play essential roles in spermiogenesis.To understand the roles played by KIF3 A/3B during spermatogenesis of large yellow croaker Larimichthys crocea,we studied the testis characteristics at different developmental stages of L.crocea,and determined the spatiotemporal expression patterns of kif3a and kif3b during spermiogenesis.Quantitative real-time PCR(qR T-PCR)showed that the overall trends of kif3 a/3 b m RNA abundance during testis development are similar.From stage Ⅱ to stage V,kif3a/3b m RNA abundances first increased and then fell after reaching a peak at stage IV.Interestingly,the m RNA abundances of both genes at stage V were higher than those at stages Ⅱ and Ⅲ.In addition,it is worth of noting that kif3 b m RNA abundance was higher than that of kif3a at all stages.Fluorescence in situ hybridization results revealed that kif3a/3b m RNA abundance dynamics were consistent with the migration of mitochondria,the deformation of nucleus,and the formation of tail.The m RNA hybridization signals of both genes first appeared either around the nuclear periphery or on the side of the nuclei,then appeared at one side of nuclei,and finally were mainly on the tail during spermiogenesis.Our findings contributed to better understanding the molecular mechanisms of spermiogenesis in fish;and suggested that KIF3A and KIF3B may participate in the intracellular transport of mitochondria,nuclear deformation,and the formation of tail during the spermiogenesis in L.crocea.
