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1.
Flatfish or flounder moves one eye to change body proportion into vertebral asymmetry during metamorphosis, during which some become sinistral while others dextral. However, the mechanism behinds the eye-position has not been well understood. In this research, hybrids between Japanese flounder(♀) and stone flounder (♂) show mixed eye-location in both dextral type and sinistral type, and thus become good samples for studying the eye-migration. mRNAs from pro-metamorphosis sinistral and dextral hybrids larvae...  相似文献   

2.
Flatfish or flounder moves one eye to change body proportion into vertebral asymmetry during metamorphosis, during which some become sinistral while others dextral. However, the mechanism behinds the eye-position has not been well understood. In this research, hybrids between Japanese flounder(♀) and stone flounder (♂) show mixed eye-location in both dextral type and sinistral type, and thus become good samples for studying the eye-migration. mRNAs from pro-metamorphosis sinistral and dextral hybrids larvae were screened with classical differential display RT-PCR (DD-RT-PCR) and representational difference analysis of cDNA (cDNA-RDA); 30 and 47 putative fragments were isolated, respectively. The cDNA fragments of creatine kinase and trypsinogen 2 precursor genes isolated by cDNA-RDA exhibited eye-position expression patterns during metamorphosis. However, none of the fragments was proved to be related to flatfishes’ eye-position specifically. Therefore, further studies and more sensitive gene isolated methods are needed to solve the problems. Supported by National Natural Science Foundation of China (No. 30600455) and the National Basic Research Program of China (973 Program, No.2004CB117402)  相似文献   

3.
AMP deaminase catalyzes the conversion of AMP into IMP and ammonia. In the present study, a full-length cDNA of AMPD1 from skeletal muscle of Japanese flounder Paralichthys olivaceus was cloned and characterized. The 2 526 bp cDNA contains a 5’-UTR of 78 bp, a 3’-UTR of 237 bp and an open reading frame (ORF) of 2 211 bp, which encodes a protein of 736 amino acids. The predicted protein contains a highly conserved AMP deaminase motif (SLSTDDP) and an ATP-binding site sequence (EPLMEEYAIAAQVFK). Phylogenetic analysis showed that the AMPD1 and AMPD3 genes originate from the same branch, but are evolutionarily distant from the AMPD2 gene. RT-PCR showed that the flounder AMPD1 gene was expressed only in skeletal muscle. QRT-PCR analysis revealed a statistically significant 2.54 fold higher level of AMPD1 mRNA in adult muscle (750±40 g) compared with juvenile muscle (7.5±2 g) (P<0.05). HPLC analysis showed that the IMP content in adult muscle (3.35±0.21 mg/g) was also statistically significantly higher than in juvenile muscle (1.08±0.04 mg/g) (P<0.05). There is a direct relationship between the AMPD1 gene expression level and IMP content in the skeletal muscle of juvenile and adult flounders. These results may provide useful information for quality improvement and molecular breeding of aquatic animals.  相似文献   

4.
Histological development of Japanese flounder Paralichthys olivaceus larval skin and ultrastructural difference of skin between reared normal and malpigmented Japanese flounder were studied with light microscopy (LM) and transmission electron microscopy (TEM). The results show that the skin develops slowly before the metamorphosis, while at the onset of metamorphosis, the skin develops quickly and becomes complete in structure till about 50d after being hatched. Ultrastructural observation on the normal and malpigmented skins shows that the iridophore and melanophore are adjacent to each other. Profile and structure of the two kinds of pigmcnt cells are more complete in the skin of normal ocular side than in the skin of pigmented blind side. The ultrastructure of typical chloride cell was observed in the skin of Japanese flounder larvae for the first time.  相似文献   

5.
Histological development of Japanese flounder Paralichthys olivaceus larval skin and ultrastructural difference of skin between reared normal and malpigmented Japanese flounder were studied with light microscopy (LM) and transmission electron microscopy (TEM). The results show that the skin develops slowly before the metamorphosis, while at the onset of metamorphosis, the skin develops quickly and becomes complete in structure till about 50d after being hatched. Ultrastructural observation on the normal and malpigmented skins shows that the iridophore and melanophore are adjacent to each other. Profile and structure of the two kinds of pigment cells are more complete in the skin of normal ocular side than in the skin of pigmented blind side. The ultrastructure of typical chloride cell was observed in the skin of Japanese flounder larvae for the first time.  相似文献   

6.
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7.
Ontogenetic changes in digestive enzyme activities and the amino acid (AA) profile of starry flounder, Platichthys stellatus, were investigated and limiting amino acids were estimated compared with the essential AA profile between larvae and live food to clarify starry flounder larval nutritional requirements. Larvae were collected at the egg stage and 0, 2, 4, 7, 12, 17, 24 days after hatching (DAH) for analysis. Larvae grew from 1.91 mm at hatching to 12.13 mm at 24 DAH. Trypsin and chymotrypsin activities changed slightly by 4 DAH and then increased significantly 4 DAH. Pepsin activity increased sharply beginning 17 DAH. Lipase activity increased significantly 4 DAH and increased progressively with larval growth. Amylase activity was also detected in newly hatched larvae and increased 7 DAH followed by a gradual decrease. High free amino acid (FAA) content was detected in starry flounder eggs (110.72 mg/g dry weight). Total FAA content dropped to 43.29 mg/g in 4-DAH larvae and then decreased gradually to 13.74 mg/g in 24-DAH larvae. Most FAAs (except lysine and methionine) decreased >50% in 4-DAH larvae compared with those in eggs and then decreased to the lowest values in 24-DAH larvae. Changes in the protein amino acid (PAA) profile were much milder than those observed for FAAs. Most PAAs increased gradually during larval development, except lysine and phenylalanine. The percentages of free threonine, valine, isoleucine, and leucine decreased until the end of the trial, whereas the protein forms of these four AAs followed the opposite trend. A comparison of the essential AA composition of live food (rotifers, Artemia nauplii, and Artemia metanauplii) and larvae suggested that methionine was potentially the first limiting AA. These results may help develop starry flounder larviculture methods by solving the AA imbalance in live food. Moreover, the increased digestive enzyme activities indicate the possibility of introducing artificial compound feed.  相似文献   

8.
Heat shock proteins 10/60(hsp10/60) are a family of conserved ubiquitously expressed heat shock proteins which are produced by cells in response to exposure to stressful conditions. Besides the chaperone and housekeeping functions, they are also known to be involved in immune response during bacterial infection. In this study, we identified and annotated 10 hsp10/60 genes through bioinformatic analysis in Japanese flounder(Paralichthys olivaceus). Among them one member of hsp10(hspe) family and nine members of hsp60(hspd) family were identified. Phylogenetic and selection pressure analysis showed that the hsp10/60 genes were evolutionarily constrained and their function was conserved. Besides, hsp10/60 genes were involved in different embryonic and larval stages and acted as the sentinel role in an unchallenged organism. In addition, we also observed the expression patterns of hsp10/60 genes after Edwardsiella tarda infection, for the first time in Japanese flounder. Eight out of 10 genes were differentially expressed after bacterial challenges, the significantly regulated expressions of flounder hsp10/60 genes after bacterial infections suggested their involvement in immune response in flounder. Our results provide valuable information for clarifying the evolutionary relationship, and early insights of the immune functions of hsp10/60 genes in Japanese flounder.  相似文献   

9.
MyoD,Myf5,and myogenin are myogenic regulatory factors that play important roles during myogenesis.It is thought that MyoD and Myf5 are required for myogenic determination,while myogenin is important for terminal differentiation and lineage maintenance.To better understand the function of myogenic regulatory factors in muscle development of flounder,an important economic fish in Asia,real-time quantitative RT-PCR was used to characterize the expression patterns of MyoD,Myf5, and myogenin at early stages of embryo development,and in different tissues of the adult flounder.The results show that,Myf5 is the first gene to be expressed during the early stages of flounder development, followed by MyoD and myogenin.The expressions of Myf5,MyoD,and myogenin at the early stages have a common characteristic:expression gradually increased to a peak level,and then gradually decreased to an extremely low level.In the adult flounder,the expression of the three genes in muscle is much higher than that in other tissues,indicating that they are important for muscle growth and maintenance of grown fish.During embryonic stages,the expression level of MyoD might serve an important role in the balance between muscle cell differentiation and proliferation.When the MyoD expression is over 30%of its highest level,the muscle cells enter the differentiation stage.  相似文献   

10.
MyoD, Myf5, and myogenin are myogenic regulatory factors that play important roles during myogenesis. It is thought that MyoD and Myf5 are required for myogenic determination, while myogenin is important for terminal differentiation and lineage maintenance. To better understand the function of myogenic regulatory factors in muscle development of flounder, an important economic fish in Asia, real-time quantitative RT-PCR was used to characterize the expression patterns of MyoD, Myf5, and myogenin at early stages of embryo development, and in different tissues of the adult flounder. The results show that, Myf5 is the first gene to be expressed during the early stages of flounder development, followed by MyoD and myogenin. The expressions of Myf5, yoD, and myogenin at the early stages have a common characteristic: expression gradually increased to a peak level, and then gradually decreased to an extremely low level. In the adult flounder, the expression of the three genes in muscle is much higher than that in other tissues, indicating that they are important for muscle growth and maintenance of grown fish. During embryonic stages, the expression level of MyoD might serve an important role in the balance between muscle cell differentiation and proliferation. When the MyoD expression is over 30% of its highest level, the muscle cells enter the differentiation stage.  相似文献   

11.
As a specific gene of fish,cytochrome P450c17-Ⅱ(CYP17-Ⅱ) gene plays a key role in the growth,development and reproduction level of fish.In this study,the single-stranded conformational polymorphism(SSCP) technique was used to characterize polymorphisms within the coding region of CYP17-Ⅱ gene in a population of 75 male Japanese flounder(Paralichthys olivaceus).Three single nucleotide polymorphisms(SNPs) were identified in CYP17-Ⅱ gene of Japanese flounder.They were c.G594A(p.G188R),c.G939A and c.G1502A(p.G490D).SNP1(c.G594A),located in exon 4 of CYP17-Ⅱ gene,was significantly associated with gonadosomatic index(GSI).Individuals with genotype GG of SNP1 had significantly lower GSI(P < 0.05) than those with geno-type AA or AG.SNP2(c.G939A) located at the CpG island of CYP17-Ⅱ gene.The mutation changed the methylation of exon 6.Indi-viduals with genotype AA of SNP2 had significantly lower serum testosterone(T) level and hepatosomatic index(HSI) compared to those with genotype GG.The results suggested that SNP2 could influence the reproductive endocrine of male Japanese flounder.How-ever,the SNP3(c.G1502A) located in exon 9 did not affect the four measured reproductive traits.This study showed that CYP17-Ⅱ gene could be a potentially useful candidate gene for the research of genetic breeding and physiological aspects of Japanese flounder.  相似文献   

12.
To reveal the key factor in self-healing from LCDV (lymphocystis disease virus)-infec Japanese flounder (Paralichthys olivaceus), serum proteins from self-healing and sick Japanese floun were separated by two-dimensional electrophoresis to screen differentially expressed proteins. Prot spots demonstrating changes greater than two-fold in the expression level were digested and furt identified in capillary liquid chromatography tandem mass spectrometry (LC-MS/MS). Two immuni relevant proteins were thus identified as transferrin and the complement component C3 of Japan flounder. These findings suggest that the two proteins may play important roles in the self-healing lymphocystis in Japanese flounder. This is an important theoretical foundation to promote self-healing LCDV-infected Japanese flounder by improving their innate immunity.  相似文献   

13.
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14.
An 8-week feeding trial was conducted to investigate the effects of dietary soy isoflavones on feeding intake,growth performance,and digestion of juvenile Japanese flounder(Paralichthys olivaceus).Four isonitrogenous(49% crude protein) and isoenergetic(20.1 MJ kg-1) diets were formulated to contain four graded levels of soy isoflavones,namely,0,1,4 and 8 g soy isoflavones in 1 kg of diet.Each diet was randomly fed to triplicate tanks of fish(Initial average weight:2.58 g ± 0.01 g),and each tank was stocked with 35 fish.No significant difference was observed among diets with levels of 0,1 and 4 g kg-1 soy isoflavones in feed intake,weight gain,feed efficiency ratio(FER),proximate composition of fish whole body and apparent digestibility coefficients(ADC) of nutrients and energy(P>0.05).However,high dietary soy isoflavones level(8 g kg-1) significantly depressed weight gain,FER,whole-body crude lipid content of fish and ADC of nutrients(P<0.05).These results indicate that high level of dietary soy isoflavones(above 4 g kg-1) significantly depresses growth responses and FER of Japanese flounder.However,as the content of soy isoflavones in soybean meal is around 1 to 3 g kg-1,the adverse effects might be neglected when soybean products are used as a fish feed ingredient.  相似文献   

15.
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16.
Lymphocystis disease, caused by the lymphocystis disease virus (LCDV), is a significant worldwide problem in fish industry causing substantial economic losses. In this study, we aimed to develop the DNA vaccine against LCDV, using DNA vaccination technology. We evaluated plasmid pEGFP-N2-LCDV1.3 kb as a DNA vaccine candidate. The plasmid DNA was transiently expressed after liposome transfection into the eukaryotic COS 7 cell line. The distribution and expression of the DNA vaccine (pEGFP-N2-LCDV1.3kb) were also analyzed in tissues of the vaccinated Japanese flounder by PCR, RT-PCR and fluorescent microscopy. Results from PCR analysis indicated that the vaccine-containing plasmids were distributed in injected muscle, the muscle opposite the injection site, the hind intestine, gill, spleen, head, kidney and liver, 6 and 25 days after vaccination. The vaccine plasmids disappeared 100 d post-vaccination. Fluorescent microscopy revealed green fluorescence in the injected muscle, the muscle opposite the injection site, the hind intestine, gill, spleen, head, kidney and liver of fish 48 h post-vaccination, green fluorescence did not appear in the control treated tissue. Green fluorescence became weak at 60 days post-vaccination. RT-PCR analysis indicated that the mcp gene was expressed in all tested tissues of vaccinated fish 6–50 days post-vaccination. These results demonstrate that the antigen encoded by the DNA vaccine is distributed and expressed in all of the tissues analyzed in the vaccinated fish. The antigen would therefore potentially initiate a specific immune response. the plasmid DNA was injected into Japanese flounder (Paralichthys olivaceus) intramuscularly and antibodies against LCDV were evaluated. The results indicate that the plasmid encoded DNA vaccine could induce an immune response to LCDV and would therefore offer immune protection against LCD. Further studies are required for the development and application of this promising DNA vaccine.  相似文献   

17.
A novel immune-related gene was expressed in Japanese flounder (Paralichthys olivaceus) injected with Vibrio anguillarum. The complete cDNA contained a 169 bp 5’UTR, a 336 bp open reading frame (ORF) encoding 111 amino acids and a 556bp 3’UTR. Six exons and five introns were identified in the PoIR2 gene. Blastp similarity comparison showed its encoding protein had 50% similarity to Danio rerio neuromedin S (NMS), but further alignment indicated they did not have NMS C-terminal conservational signature domain. So it was not defined as an NMS homologue. Protein structure analysis indicated it had a 26aa signal peptide and was a secretory pathway protein. RT-PCR demonstrated that the expression of PoIR2 was quickly induced and drastically increased in liver, kidney, spleen, gills, intestine, heart, and skeletal muscle after infected with V. anguillarum. These results indicated that the PoIR2 might play some important role in Japanese flounder immune response system. This gene was named PoIR2 (P.olivaceus immune-related gene 2, GenBank accession number: EU224372). The mature PoIR2 peptide was expressed in BL21(DE3) pLysS using pET-32a(+) vector and a great part of the recombinant mature peptide existed as soluble type.  相似文献   

18.
Japanese flounder is one of the most important commercial species in China; however, information on the genetic background of natural populations in China seas is scarce. The lack of genetic data has hampered fishery management and aquaculture development programs for this species. In the present study, we have analyzed the genetic diversity in natural populations of Japanese flounder sampled from the Yellow Sea (Qingdao population, QD) and East China Sea (Zhoushan population, ZS) using 10 polymorphic microsatellite loci and cytochrome c oxidase subunit I (COI) sequencing data. A total of 68 different alleles were observed over 10 microsatellite loci. The total number of alleles per locus ranged from 2 to 9, and the number of genotypes per locus ranged from 3 to 45. The observed heterozygosity and expected heterozygosity in QD were 0.733 and 0.779, respectively, and in ZS the heterozygosity values were 0.708 and 0.783, respectively. Significant departures from Hardy-Weinberg equilibrium were observed in 7 of the 10 microsatellite loci in each of the two populations. The COI sequencing analysis revealed 25 polymorphic sites and 15 haplotypes in the two populations. The haplotype diversity and nucleotide diversity in the QD population were 0.746±0.072 8 and 0.003 34±0.001 03 respectively, and in ZS population the genetic diversity values were 0.712±0.047 0 and 0.003 18±0.000 49, respectively. The microsatellite data (F_st =0.048 7, P<0.001) and mitochondrial DNA data (F_st =0.128, P<0.001) both revealed significant genetic differentiation between the two populations. The information on the genetic variation and differentiation in Japanese flounder obtained in this study could be used to set up suitable guidelines for the management and conservation of this species, as well as for managing artificial selection programs. In future studies, more geographically diverse stocks should be used to obtain a deeper understanding of the population structure of Japanese flounder in the China seas and adjacent regions.  相似文献   

19.
Ontogenetic changes in digestive enzyme activities and the amino acid(AA) profile of starry flounder,Platichthys stellatus,were investigated and limiting amino acids were estimated compared with the essential AA profile between larvae and live food to clarify starry flounder larval nutritional requirements.Larvae were collected at the egg stage and 0,2,4,7,12,17,24 days after hatching(DAH)for analysis.Larvae grew from 1.91 mm at hatching to 12.13 mm at 24 DAH.Trypsin and chymotrypsin activities changed slightly by 4 DAH and then increased significantly 4 DAH.Pepsin activity increased sharply beginning 17 DAH.Lipase activity increased significantly 4 DAH and increased progressively with larval growth.Amylase activity was also detected in newly hatched larvae and increased 7 DAH followed by a gradual decrease.High free amino acid(FAA) content was detected in starry flounder eggs(110.72mg/g dry weight).Total FAA content dropped to 43.29 mg/g in 4-DAH larvae and then decreased gradually to 13.74 mg/g in 24-DAH larvae.Most FAAs(except lysine and methionine) decreased 50%in 4-DAH larvae compared with those in eggs and then decreased to the lowest values in 24-DAH larvae.Changes in the protein amino acid(PAA) profile were much milder than those observed for FAAs.Most PAAs increased gradually during larval development,except lysine and phenylalanine.The percentages of free threonine,valine,isoleucine,and leucine decreased until the end of the trial,whereas the protein forms of these four AAs followed the opposite trend.A comparison of the essential AA composition of live food(rotifers,Artemia nauplii,and Artemia metanauplii) and larvae suggested that methionine was potentially the first limiting AA.These results may help develop starry flounder larviculture methods by solving the AA imbalance in live food.Moreover,the increased digestive enzyme activities indicate the possibility of introducing artificial compound feed.  相似文献   

20.
Soybean stachyose (SBS) and phytic acid (PA) are anti-nutritional factors (ANF) which have deleterious effects on the growth and digestibility in fish. The present research studied the effects of dietary SBS and PA on the expression of three serine protease genes in the liver of Japanese flounder (Paralichthys olivaceus). These genes are trypsinogen 1 (poTRY), elastase 1 (poEL) and chymotrypsinogen 1 (poCTRY). Eight artificial diets with graded levels of supplemented ANFs were formulated to 4 levels of SBS ...  相似文献   

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