This study cloned the hemoglobin a1 from the marine teleost, the half-smooth tongue sole （Cynoglossus semilaevis）, and then examined its expression under hypoxia exposure. The full-length of CsHb-a1 （594 bp） cDNA ...This study cloned the hemoglobin a1 from the marine teleost, the half-smooth tongue sole （Cynoglossus semilaevis）, and then examined its expression under hypoxia exposure. The full-length of CsHb-a1 （594 bp） cDNA contains an open reading frame encoding 144 amino acids. Sequence analysis shows that the predicted CsHb-a1 amino acids shares high identities with that of other species. Real-time PCR showed that CsHb-a1 was highly expressed in the heart, liver, spleen, kidney and blood. Five to 120 min esposure and long-term （36 h） exposure to hypoxia （1.0 mg/L） significantly increased CsHb-a1 mRNA expression in most tissues compared to those fish held in normoxic conditions （dissolved oxygen （DO）： 6.2 mg/L）. These results suggested that the up-regulation of Hb-a1 is an important component for adaptation of half-smooth tongue sole to short-term hypoxia.展开更多
To investigate the expression characteristics of sex related gene of FTZ-F 1 in the half-smooth tongue-sole （Cynoglossus semilaevis）, the homologue FTZ-F1 （hsFTZ-F1） full-length cDNA was isolated from the testis b...To investigate the expression characteristics of sex related gene of FTZ-F 1 in the half-smooth tongue-sole （Cynoglossus semilaevis）, the homologue FTZ-F1 （hsFTZ-F1） full-length cDNA was isolated from the testis by homologous cloning, and the cDNA included the open reading frame and a 66bp 5＇-UTR, along with a 1619bp 3＇-UTR, encoding a predicted 485 amino acid protein. Sequence, tissue distribution and phylogenic analyses of the FTZ-F1 showed that the hsFTZ-F1 belonged to SF-1/Ad4BP group. The hsFTZ-F1 transcripts were highly abundant in the gonads, kidneys, brain and head-kidneys, but weakly in other tissues. However, the expression level in the brain and head-kidney of female was highly abundant than in the male. The hsFTZ-F1 expression was highly abundant in the embryo than in the larvae, which suggested that the hsFTZ-F1 may be involved in the organogenesis in the tongue sole.展开更多
In this study, the pathogen causing skin ulcer disease in Cynoglossus semilaevis Gunther was isolated for morphological observation, physiological and bio- chemical identification. According to the result, the isolate...In this study, the pathogen causing skin ulcer disease in Cynoglossus semilaevis Gunther was isolated for morphological observation, physiological and bio- chemical identification. According to the result, the isolated pathogen was identified as Vibrio harveyi. The results of recurrent infection of C. semilaevis Gonther showed that the pathogen was strongly pathogenic to C. semilaevis Gunther. In or- der to explore the pathogenesis, outer membrane protein （OMP） gene of C. semi- laevis Gunther was detected by PCR. The results showed that all the three repre- sentative strains harbored OMP gene. According to the results of sensitivity test of the pathogen to Chinese herbal medicine, Galla Chinensis, Fructus Mume, Fructus Hippophae and Lignum Sappan exerted strong antibacterial effects against V. harveyr, Pericarpium Granati exhibited slight antibacterial effect against V. harveyi; Pericarpium Citri Reticulatae, Rhizoma Acori GramineL Herba Houttuyniae, Herba Portulacae, Herba Andrographis, Eucalyptus globulus Labill. and Herba Menthae Heplocalycis had little effect on V. harveyi. Galla Chinensis, Fructus Mume, Fructus Hippophae and Lignum Sappan were prepared into three prescriptions, among which prescription 1 （Galla Chinensis ＋ Fructus Mume） exhibited the strongest antibacterial effect.展开更多
The histopathological changes in various organs of Cynoglossus semilaevis Günther infected with red abdominal shell disease were observed by dissection and HE staining. In the ill C. semilaevis, the body surface ...The histopathological changes in various organs of Cynoglossus semilaevis Günther infected with red abdominal shell disease were observed by dissection and HE staining. In the ill C. semilaevis, the body surface was congestive and bleeding;the skin in the blind side ulcerated with extravasated blood; the gill filaments ulcerated with a lot of mucus; the liver, pancreas and spleen were swelling and bleeding with extravasated blood; the small intestine was congestive and bleeding. Degeneration and necrosis, and submucosal bleeding occurred in the skin of C. semilaevis infected with red abdominal shell disease. There was red blood cell infiltration and deposition in the space among muscle fibers. Epithelial degeneration and necrosis occurred in the parotid gland. The efferent branchial artery was congestive. The myocardial fibers had a loose structure, and a large area of fracture appeared. The liver cells were swelling with degeneration and necrosis and concentrated nucleus. A large area of the renal interstitial was broken down and necrotic. The submucosa of the small intestine had necrosis and hemorrhage.展开更多
Two transcription factors, Sox9a and Foxl2 were cloned from half-smooth tongue sole （Cynoglossus semilaevis）. Sox9a is a new duplication of C.semilaevis Sox9 gene. The complete cDNA of Sox9a gene was 1 842 bp long c...Two transcription factors, Sox9a and Foxl2 were cloned from half-smooth tongue sole （Cynoglossus semilaevis）. Sox9a is a new duplication of C.semilaevis Sox9 gene. The complete cDNA of Sox9a gene was 1 842 bp long coding for 487 amino acids and Foxl2 gene was 1 817 bp coding for 308 amino acids. Sox9a was expressed higher in male brain, pituitary and gonad and Foxl2 were higher in female brain, pituitary and gonad. The expression of Sox9a gene in gonads of neo-males was higher than that of normal females. Sox9a and Foxl2 were expressed higher in gastrula stage than in other stages. In the period of sex differentiation, the expression of Sox9a was first going up and then going down and Foxl2 was higher expressed at 37 dph. The highest expressions of Sox9a and Foxl2 genes occurred in nine-month and 12-month old gonad tissues, respectively. Sox9a gene was considered to have inevitable links with sex reversal, sex differentiation and cell differentiation of embryos and formation of spermatogenic ceils. Foxl2 was considered to play a role in sex differentiation, cell differentiation of embryos but not to be necessary for sex determination and sex reversal.展开更多
Studies were conducted to determine the cause of the acute mortality of half-smooth tongue sole Cynoglossus semilaevis Günther juveniles in a fish farm in Jimo, Shandong Province, China, in June 2006. Gross signs...Studies were conducted to determine the cause of the acute mortality of half-smooth tongue sole Cynoglossus semilaevis Günther juveniles in a fish farm in Jimo, Shandong Province, China, in June 2006. Gross signs of the diseased tongue sole included several petechiae and ecchymoses on the body and fin necrosis and hemorrhagic lesion at the base of the fin. Bacteria were isolated from kidney, liver and hemorrhagic lesions of the diseased tongue sole. Among 14 strains, SJ060621 was proved to be highly virulent to juvenile tongue sole with LD50 value of 〈1.0×10^5 colony forming units （CFU）mL^-1, while the remaining 13 were avirulent. Among the 16 antibiotics tested, SJ060621 was sensitive to gentamicin and nitrofurantoin. It was identified as Listonella anguillantm with conventional plate and tube tests in combination with API 20E analysis. 16S rRNA gene and partial HSP60 gene sequenceing analysis revealed that the strain was highly homologous with L. anguillarum. Examination of the infected musculature by electron microscopy indicated numerous bacteria and lots of macrophages containing phagocytosed bacteria. Histopathological investigations revealed severe necrotic degenerative changes in the infected organs. Indirect immunofluorescence assay （IFA） was employed to detect the location of occurrence of bacteria, and bacteria were found in aggregations in the inflammatory areas in musculature.展开更多
Starving and re-feeding trials were conducted to evaluate the effects of starvation duration and recovery times on the growth performance and physiological characteristics of juvenile tongue sole Cynoglossus semilaevi...Starving and re-feeding trials were conducted to evaluate the effects of starvation duration and recovery times on the growth performance and physiological characteristics of juvenile tongue sole Cynoglossus semilaevis, which included growth, body composition, intestinal morphology and digestive enzymes activities. The fish starved for one(D1), two(D2) and four(D4) days, respectively, were recovered for three(R3, R6, R12), seven(R7, R14, R28) and eleven(R11, R22, R44) folds of starvation days while the control fish were fed constantly. The experiment was conducted for 96 days. The fish individuals in D1R11, D2R14 and D2R22 caught up in weight with the control, indicating that complete compensatory growth existed in these fish individuals. The highest body weight gain and total specific growth rates were observed in D2R22. Food intake increased significantly in most treatments in comparison with that of the control except for D1R7 and D2R22(P < 0.05). Food conversion efficiency and apparent digest coefficient in D2R22 were significantly promoted, being higher than that of the control(P < 0.05). The activities of trypsin and lipase were found to be closely related to the growth performance. The activities of liver and hindgut trypsin, also midgut and hindgut lipase in D2R22 were significantly higher than those of the control(P < 0.05). The fold height(HF) of foregut and midgut increased significantly in D2R22, and HF decreased significantly in D1R3, D2R6 and D4R12(P < 0.05). On our findings, we may conclude that the optimum starving and re-feeding strategy is starving for 2 days and re-feeding for 22 days. And in this starving and re-feeding strategy, the compensatory growth could be mostly attributed to the promotion of food conversion efficiency and digestibility coefficiency.展开更多
A complementary DNA(cDNA) library was constructed from half-smooth tongue sole spleen. A long-read expressed sequence tag(EST) database was generated,containing 3100 cDNA clones,of which 220 clones were fully sequence...A complementary DNA(cDNA) library was constructed from half-smooth tongue sole spleen. A long-read expressed sequence tag(EST) database was generated,containing 3100 cDNA clones,of which 220 clones were fully sequenced. A total of 1060 non-redundant simple sequence repeats(SSRs) were obtained from the cDNA library. An average of 5 kb sequence generates 1 SSR in the half-smooth tongue sole spleen cDNA library. The proportion of the SSR unit size was different in the cDNA library. The monomeric repeats(51.4%) are the most abundant class of SSR in the dataset. The dimeric,trimeric,tetrameric and hexameric re-peats are represented in decreasing proportions of 27.2%,16.0%,2.8% and 1.9%,respectively. The frequency of pentameric repeats was observed the least(only 0.7%) . Most of the monomeric and dimeric repeats are distributed in 3' and 5' un-translation region. If translation regions are considered merely,trimeric repeats are the highest,accounting for 57% of the total microsatellites.展开更多
Two female-specific AFLP(amplified fragment length polymorphism)markers(named CseF464 and CseF136)were isolated by using one selective primer combination(E-AGC/M-CTG)from the genomic DNA of 20 females and 20 males of ...Two female-specific AFLP(amplified fragment length polymorphism)markers(named CseF464 and CseF136)were isolated by using one selective primer combination(E-AGC/M-CTG)from the genomic DNA of 20 females and 20 males of the half-smooth tongue sole Cynoglossus semilaevis.Both the markers were re-amplified,recovered from the agarose gels,cloned and sequenced.Bioinformatics analysis indicated that the length of the two markers were 468 bp and 134 bp,respectively,and the sequences showed no similarity to each other,as well as to the known sequences deposited in the GenBank database using BLASTn.Two pairs of SCAR(sequence characterized amplified regions)primers were designed based on the sequences of the two female-specific markers.Furthermore,PCR-based genetic sex identification method was developed in Cynoglossus semilaevis.A specific fragment was amplified in all females but not in any males by using these SCAR primers on the initial 20 female and 20 male individuals of Cynoglossus semilaevis.The feasibility of the two SCAR primer pairs was confirmed in additional 100 individuals(50 females and 50 males).This allowed for reliable,rapid molecular identification of genetic sex of the species,genetic mapping on the sex chromosomes and better understanding of the sex determination and sex differentiation in the half-smooth tongue sole.展开更多
Half-smooth tongue sole （Cynoglossus semilaevis） is a rare marine flatfish whose mature ovary and testis greatly differ in volume and weight. The length and weight of mature females are over twice greater than those...Half-smooth tongue sole （Cynoglossus semilaevis） is a rare marine flatfish whose mature ovary and testis greatly differ in volume and weight. The length and weight of mature females are over twice greater than those of mature males. To obtain sufficient information on gonad differentiation and the relationship between gonad development and growth in the fish, we compared gene expression between the ovary and testis using suppression subtractive hybridization （SSH）. Testis cDNAs are subtracted from ovary cDNAs and are used to es- tablish an ovary testis-subtracted cDNA library. A total of 41 nonredundant clones are identified, including 20 known cDNAs, 9 unchar-acterized cDNAs （EST clones）, and 12 novel sequences. For selected genes such as ZPC, RacGAP, survivin, aquaporin, CPEB, O5, O15, and O18, gene expression patterns are analyzed by reverse transcriptase-polymerase chain reaction （RT-PCR）. The results confirm that these genes are only expressed in the ovary and not in the testis, or at higher levels in the ovary than in the testis. At the same time, expressions of certain genes such as ZPC, survivin, aquaporin, CPEB, and O15 are demonstrated to possess sexual dimorphism in the kidney or muscle, and spleen. The results suggest that these genes could play key roles not only in the ovary but in other female tissues as well.展开更多
Differential expression of genes is crucial to growth and development of fish. To select the appropriate genes for gene normalization during Cynoglossus semilaevis early developmental process, eight candidate referenc...Differential expression of genes is crucial to growth and development of fish. To select the appropriate genes for gene normalization during Cynoglossus semilaevis early developmental process, eight candidate reference genes （ACTB, B2M, EF1A, GADPH, RPL7, TUBA, UBCE and 18S） were tested for their adequacy by using quantitative real-time PCR. The results showed that the expression of all the examined genes exhibited tissue dependent variations in the mature C. semilaevis. EFIA was listed as the most stable reference among the 14 tissues by RefFinder. Furthermore, the recommended comprehensive ranking of the stability determined by RefFinder showed that 18S was the most stable gene during the early developmental stages （from oosphere to 90 days old） in this study. However, when divided the Ct value data of the above mentioned early developmental stages into two separate periods （embryo and post-hatching periods）, TUBA and 18S represented the most stable references of these two developmental periods, respectively. Consequently, the reference gene should be carefully and accurately chosen even for studies of the same species at various developmental processes. The relevant data may help in selecting appropriate reference genes for mRNA expression analysis, and is of great value in the studies of fish growth and development.展开更多
The dmrt1 (doublesex and mab-3 related transcription factor 1) gene is considered to play an essential role in testis differentiation and development among metazoan species. As an economically important marine fish in...The dmrt1 (doublesex and mab-3 related transcription factor 1) gene is considered to play an essential role in testis differentiation and development among metazoan species. As an economically important marine fish in China, Chinese tongue sole (Cynoglossus semilaevis) possess a ZW/ZZ sex-determining system, and the females usually grow two to four times bigger than males. Previous studies have confirmed that Z-linked dmrt1 gene is the male determining gene in C. semilaevis and TALENs-mediated knocking-out individuals showed increased growth phenotype. In order to investigate the function of dmrt1 regulatory regions and its potential application, we have cloned the promoter of C. semilaevis dmrt1. The acquired sequence consisted of a 5'-upstream sequence and a partial exon1;functional analysis showed that there were two positive regulatory regions in the promoter, as well as one negative region and one neutral region. These positive regions were then combined to obtain several newly constructed promoters. Both in vitro and in vivo analysis confirmed one of them (dmrt1-Δ3+Δ4) showed elevated promoting activity compared to the full-length promoter and could drive exogenous gene expression in tongue sole gonads. Our results will provide useful information for understanding the regulatory mechanism of dmrt1 gene during C. semilaevis sex determination, and the endogenous promoter will facilitate the transgenic research for analyzing sex- and growth-related genes.展开更多
Examination of the food habits and seasonal variation of the stomach contents of adult tongue sole, Cynoglossus semilaevisGunther) taken in July 1982-July 1983 from Laizhou Bay and the Huanghe River estuary of the Boh...Examination of the food habits and seasonal variation of the stomach contents of adult tongue sole, Cynoglossus semilaevisGunther) taken in July 1982-July 1983 from Laizhou Bay and the Huanghe River estuary of the Bohai Sea showed Crustacea, bivalvia and small fishes comprised the main prey. Invertebrates such as polychaeta, cephalopoda, gastropoda, echinodermata and actiniaria were also intermittently found in them. They intensively fed all the year round (monthly feeding rate of over 80%). The main food items were Alpheus japonica, Alpheus distinguendus, Oratosquilla oratorio, Eucrate crenata and Carcinoplax vestitus, etc. In summer and autumn, the portion of bivalvia such as Cultellus attenuatus and Musculus senhousei increased steadily. From summer to winter, a stable proportion of small fishes such as Rhinogobius pflaumi and Setipinna taty was in the diet.展开更多
The Chinese tongue sole(Cynoglossus semilaevis) is widely cultured in the coastal region of East Asia and has excellent economic value. However, the high albino rate of the breeding population has caused a significant...The Chinese tongue sole(Cynoglossus semilaevis) is widely cultured in the coastal region of East Asia and has excellent economic value. However, the high albino rate of the breeding population has caused a significant loss to the aquaculture industry. To study the molecular mechanism of albinism, the present study used an albino Chinese tongue sole family to construct three simple sequence repeat(SSR) linkage groups, and draft a preliminary linkage map related to albinism. After albinism-related loci mapping, 18 albinism-related loci were detected under two models(containing 2407 genes) compared to the Chinese tongue sole genome. One of these loci, the tyrosinase related protein(tyrp2), which has been reported previously as an important gene regulating both eumelanin and phaeomelanin levels, was indicated to be the possible cause of albinism. Thirty-five Gene Ontology(GO) terms and 14 Kyoto Encyclopedia of Genes and Genome pathways were annotated via bioinformatic analyses. One GO term with protein tyrosine kinase activity, which contained 10 genes, was previously suggested to affect fish albinism. These results establish a foundation for further in-depth study of albinism in Chinese tongue sole.展开更多
Half-smooth tongue sole（Cynoglossus semilaevis） is a commercially important fish species. There were no reports about accurate genetic parameters of growth traits in C. semilaevis, despite efforts aimed at the cultu...Half-smooth tongue sole（Cynoglossus semilaevis） is a commercially important fish species. There were no reports about accurate genetic parameters of growth traits in C. semilaevis, despite efforts aimed at the culture of this species. Therefore, the main goal of this study was to estimate the parameters for the early growth traits（total length, body depth and body weight） of C. semilaevis based on the data obtained from 80 families. The trait of fish with pure white bottom or not（named as the trait of bottom color） was also analyzed. All the heritabilities estimated for the traits were medium, which varied from 0.210 to 0.362. Genetic correlations among growth traits were highly positive, varying from 0.913 to 0.959, indicating that selection of one of the three traits would result in correlated increase in the others. Also, genetic correlations between bottom color and growth traits were positive and varying from 0.241 to 0.353, suggesting that selection for the bottom color can be utilized to enhance the selection of growth traits. In addition, fish from the top performing 16 full-sib families were selected as broodstock, based on the above analysis and the comparison of family breeding value. This research provides an important basic material to implement selective breeding in C. semilaevis.展开更多
Pituitary adenylate cyclase activating polypeptide(PACAP)and growth hormone-releasing hormone(GHRH)play important roles in the GH/IGF growth axis in fishes.To determine whether epigenetic change is involved in the reg...Pituitary adenylate cyclase activating polypeptide(PACAP)and growth hormone-releasing hormone(GHRH)play important roles in the GH/IGF growth axis in fishes.To determine whether epigenetic change is involved in the regulation of pacap and ghrh responses to low salinity stress in Cynoglossus semilaevis,the correlation between growth traits,DNA methylation status and gene expression level in low salinity(15,S15)and optimal salinity(30,S30)at day 7(D7)and day 60(D60)were analyzed.Results showed that exposure to low salinity for 60 days attenuated C.semilaevis growth rate.Under low salinity,DNA methylation level of pacap promoter increased in females and decreased in males at day 7,but inverted at day 60.Additionally,pacap expression was up-regulated in both males and females.The pacap promoter methylation level was higher and expression level was lower in female than in male.The results suggest that pacap promoter methylation level is negatively correlated to mRNA level and positively correlated to body weight,while gene expression level is negatively related with body weight.With the decrease of salinity,DNA methylation level of ghrh promoter and exon1,as well as its gene expression displayed minor changes.Overall,pacap gene seems to play an important role in fish growth,contributing to female growth superiority,while ghrh gene seems not pertinent under salinity stress.The results indicate that low salinity potentially affects fish growth through regulating DNA methylation in pacap promoter.This study expands the understanding of the molecular mechanism of how salinity modulates fish growth from the epigenetic perspective.展开更多
The morphology and structure of the olfactory organ of Cynoglossus semilaevis Gunther are described. The oval olfactory sacs on both sides differ in size and in the number of lamellae, With those on the abocular side ...The morphology and structure of the olfactory organ of Cynoglossus semilaevis Gunther are described. The oval olfactory sacs on both sides differ in size and in the number of lamellae, With those on the abocular side having smaller sacs and fewer lamellae than those on the ocular side. On the ocular side, the average ratio of sac length to eye diameter is 2.1 （i.e.〉1） with an average of 91 lamellae, while on the abocular side, the values were 1.7 （i.e.〉1） and 69, respectively. In addition, the surface morphology varies in different parts of the lamella. The frontal part, near the anterior nostril, is a non-sensory margin with cilia-free epidermal cells. Within this is an internal ciliated sensory area, which is intercalated with ciliated receptor cells and a few ciliated non-sensory cells. Additionally, some dense ciliated non-sensory cells make up a non-sensory area, which also contains cilia-free epidermal cells distributed in patches. In the rear of the olfactory sac near the posterior nostril, the lamellae differ in morphology from those of the frontal olfactory sac but are similar in having few ciliated receptor cells. In other words, the surface of the lamellae in the rear part of the olfactory sac is mainly non-sensory. At present, four types of lamellae （~ E IlIand IV） have been recognized in relation to the pattern of the sensory epithelium. In this study, the frontal and rear lamellae resembled types I and IV, respectively, but are referred to as types r and IV because they are slightly less developed. Data on the ratio of length of lamellae to eye diameter, number of lamellae and the type of surface pattern of the lamellae show that the development of the olfactory system of C. semilaevis facilitates prey capture.展开更多
Effects of the amplitude(± 2, ± 4, ± 6, and ± 8) and frequency(2, 4, and 8 d) of salinity fluctuation on the body composition and energy budget of juvenile tongue sole(Cynoglossus semilaevis) were ...Effects of the amplitude(± 2, ± 4, ± 6, and ± 8) and frequency(2, 4, and 8 d) of salinity fluctuation on the body composition and energy budget of juvenile tongue sole(Cynoglossus semilaevis) were investigated in a 64-d experiment. Results showed that the amplitude and frequency of salinity fluctuation had significant interaction and both substantially affected the final weight and specific growth rate of juvenile tongue sole. The tongue sole exhibited better growth in treatments with moderate amplitude and frequency of salinity fluctuation(amplitude ± 4–6; frequency 4–8 d) than in other treatments and the control. In terms of energy budget, salinity fluctuation strongly affected the proportions of energy components, including those deposited for growth and lost in respiration, feces, and excretion. Moderately amplitude and frequency of salinity fluctuationg that favored the growth of tongue sole partitioned more energy for growth and less energy for metabolism than the constant and other amplitude and frequency of salinity fluctuation. Average energy budget for tongue sole at moderately fluctuating salinity was determined to be 100C(food) = 30.92G(growth) + 10.30F(feces) + 6.77U(excretion) + 52.01R(respiration). Energetic advantage at moderately fluctuating salinity, including increased energy intake, high assimilation efficiency, reduced metabolism expenditure, and more energy partitioned into growth, might account for the enhancement of tongue sole growth. Commercial farmers are recommended to rear juvenile tongue sole with moderate salinity fluctuations for better growth performance of this species.展开更多
The genetic diversity of wild and hatchery populations of half-smooth tongue sole Cynoglossus semilaevis, based on observation of amplified fragment length polymorphism (AFLP) was described. Two hundred individuals fr...The genetic diversity of wild and hatchery populations of half-smooth tongue sole Cynoglossus semilaevis, based on observation of amplified fragment length polymorphism (AFLP) was described. Two hundred individuals from four wild populations, Laizhou (LZ), Weihai (WH), Qingdao (QD), Rizhao (RZ), and one hatchery population, Mingbo (MB), were screened using eight different AFLP primer combinations. A total of 384 loci were screened in the five studied populations. 48.4%, 51.3%, 50.7%, 49.3% and 45.8% of these loci were polymorphic among the individuals tested in the LZ, WH, QD, RZ and MB populations, respectively. The number of polymorphic loci detected by single primer combinations ranged from 17 to 35. The average heterozygosity of the LZ, WH, QD, RZ and MB populations was 0.072, 0.093, 0.092, 0.090 and 0.063, respectively. The WH population showed the highest genetic diversity in terms of total number of AFLP bands, total number of polymorphic bands, average heterozygosity and percentage of low frequency (0-0.2) polymorphic loci among all the populations, while the LZ population was the lowest among the wild populations. Compared with the wild populations, the hatchery population showed a low genetic viability.展开更多
Phenotypic and genetic parameters for growth-related traits in the half-smooth tongue sole, Cynoglossus semilaevis, were estimated in 22 full-sib families produced by normal and neo-male breeding stocks. As phenotypic...Phenotypic and genetic parameters for growth-related traits in the half-smooth tongue sole, Cynoglossus semilaevis, were estimated in 22 full-sib families produced by normal and neo-male breeding stocks. As phenotypic males with female genotypes, neo-males are harmful in C. semilaevis aquaculture because they reduce overall production. The present study evaluated the difference in the growth-related traits： total length （TL）, body weight （BW） and square root of body weight （SQ_BW） at the age of 570 days between normal and neo-male offspring （neo-males used as male parents）. The difference in the proportion of females between normal and neo-male offspring was also assessed. Based on the linear mixed model, restricted maximum likelihood （REML） and best linear unbiased prediction （BLUP） were used to estimate various （co）variance components and estimated breeding values （EBVs） of growth-related traits. As a result, all the mean values of the three studied traits were significantly larger in normal offspring than in neo-male offspring. Additionally, the female proportion was significantly larger in normal offspring than in neo-male offspring. Heritability was 0.128＋0.066 2 for TL, 0.128-4-0.065 5 for BW and 0.132~0.062 9 for SQBW, all of which were low level heritabilities. The correlation coefficients of EBVs and phenotypic values of the target traits were 0.516 for TL, 0.524 for BW and 0.506 for SQ_BW, all of which were highly significant （P〈0.01）. Genetic correlations among TL, BW and SQ_BW were positive high （0.921-0.969） and higher than those of phenotype （0.711-0.748）, both of which had low standard errors （0.063-0.123 for genotype, and 0.010-0.018 for phenotype）. Compared with normal offspring, neo-male offspring have lower breeding values for each studied trait through EBVs comparison. Therefore, neo-male offspring should not be used as broodstock in a C. semilaevis breeding programs.展开更多
基金supported by Nature Science Foundation of Jiangsu Province(BK2011418)the Graduate Research and Innovation of Colleges and Universities in Jiangsu Province(CX09B_106Z)Natural Science Foundation of the Jiangsu Higher Education Institutions of China(09KJD240004)
文摘This study cloned the hemoglobin a1 from the marine teleost, the half-smooth tongue sole （Cynoglossus semilaevis）, and then examined its expression under hypoxia exposure. The full-length of CsHb-a1 （594 bp） cDNA contains an open reading frame encoding 144 amino acids. Sequence analysis shows that the predicted CsHb-a1 amino acids shares high identities with that of other species. Real-time PCR showed that CsHb-a1 was highly expressed in the heart, liver, spleen, kidney and blood. Five to 120 min esposure and long-term （36 h） exposure to hypoxia （1.0 mg/L） significantly increased CsHb-a1 mRNA expression in most tissues compared to those fish held in normoxic conditions （dissolved oxygen （DO）： 6.2 mg/L）. These results suggested that the up-regulation of Hb-a1 is an important component for adaptation of half-smooth tongue sole to short-term hypoxia.
基金Supported by grants from State 863 High-Technology R&D Project of China(2006AA10A403)Shandong Genetic Improvement Key Project for Agricultural OrganismDoctor Initial Funding of Guangdong Ocean University(0712103)
文摘To investigate the expression characteristics of sex related gene of FTZ-F 1 in the half-smooth tongue-sole （Cynoglossus semilaevis）, the homologue FTZ-F1 （hsFTZ-F1） full-length cDNA was isolated from the testis by homologous cloning, and the cDNA included the open reading frame and a 66bp 5＇-UTR, along with a 1619bp 3＇-UTR, encoding a predicted 485 amino acid protein. Sequence, tissue distribution and phylogenic analyses of the FTZ-F1 showed that the hsFTZ-F1 belonged to SF-1/Ad4BP group. The hsFTZ-F1 transcripts were highly abundant in the gonads, kidneys, brain and head-kidneys, but weakly in other tissues. However, the expression level in the brain and head-kidney of female was highly abundant than in the male. The hsFTZ-F1 expression was highly abundant in the embryo than in the larvae, which suggested that the hsFTZ-F1 may be involved in the organogenesis in the tongue sole.
基金Supported by Post-award Grants Program of Science and Technology Department of Hebei Province(15926620H)Science and Technology Support Program of Qinhuangdao Municipal Bureau of Science and Technology(201401A067,201402B043)~~
文摘In this study, the pathogen causing skin ulcer disease in Cynoglossus semilaevis Gunther was isolated for morphological observation, physiological and bio- chemical identification. According to the result, the isolated pathogen was identified as Vibrio harveyi. The results of recurrent infection of C. semilaevis Gonther showed that the pathogen was strongly pathogenic to C. semilaevis Gunther. In or- der to explore the pathogenesis, outer membrane protein （OMP） gene of C. semi- laevis Gunther was detected by PCR. The results showed that all the three repre- sentative strains harbored OMP gene. According to the results of sensitivity test of the pathogen to Chinese herbal medicine, Galla Chinensis, Fructus Mume, Fructus Hippophae and Lignum Sappan exerted strong antibacterial effects against V. harveyr, Pericarpium Granati exhibited slight antibacterial effect against V. harveyi; Pericarpium Citri Reticulatae, Rhizoma Acori GramineL Herba Houttuyniae, Herba Portulacae, Herba Andrographis, Eucalyptus globulus Labill. and Herba Menthae Heplocalycis had little effect on V. harveyi. Galla Chinensis, Fructus Mume, Fructus Hippophae and Lignum Sappan were prepared into three prescriptions, among which prescription 1 （Galla Chinensis ＋ Fructus Mume） exhibited the strongest antibacterial effect.
基金Supported by Incentive Program Subsidized by Department of Science and Technology of Hebei Province(15926620H)Key Technology Research and Development Program of Science and Technology Bureau of Qinhuangdao City(201401A067,201402B043)~~
文摘The histopathological changes in various organs of Cynoglossus semilaevis Günther infected with red abdominal shell disease were observed by dissection and HE staining. In the ill C. semilaevis, the body surface was congestive and bleeding;the skin in the blind side ulcerated with extravasated blood; the gill filaments ulcerated with a lot of mucus; the liver, pancreas and spleen were swelling and bleeding with extravasated blood; the small intestine was congestive and bleeding. Degeneration and necrosis, and submucosal bleeding occurred in the skin of C. semilaevis infected with red abdominal shell disease. There was red blood cell infiltration and deposition in the space among muscle fibers. Epithelial degeneration and necrosis occurred in the parotid gland. The efferent branchial artery was congestive. The myocardial fibers had a loose structure, and a large area of fracture appeared. The liver cells were swelling with degeneration and necrosis and concentrated nucleus. A large area of the renal interstitial was broken down and necrotic. The submucosa of the small intestine had necrosis and hemorrhage.
基金The National High Technology Research and Development Program of China (863 Program) under contract No.2006AA10A401the Taishan Scholar Project of Shandong Province,Chinathe National Natural Science Foundation of China under contract Nos 41006107 and 30972244
文摘Two transcription factors, Sox9a and Foxl2 were cloned from half-smooth tongue sole （Cynoglossus semilaevis）. Sox9a is a new duplication of C.semilaevis Sox9 gene. The complete cDNA of Sox9a gene was 1 842 bp long coding for 487 amino acids and Foxl2 gene was 1 817 bp coding for 308 amino acids. Sox9a was expressed higher in male brain, pituitary and gonad and Foxl2 were higher in female brain, pituitary and gonad. The expression of Sox9a gene in gonads of neo-males was higher than that of normal females. Sox9a and Foxl2 were expressed higher in gastrula stage than in other stages. In the period of sex differentiation, the expression of Sox9a was first going up and then going down and Foxl2 was higher expressed at 37 dph. The highest expressions of Sox9a and Foxl2 genes occurred in nine-month and 12-month old gonad tissues, respectively. Sox9a gene was considered to have inevitable links with sex reversal, sex differentiation and cell differentiation of embryos and formation of spermatogenic ceils. Foxl2 was considered to play a role in sex differentiation, cell differentiation of embryos but not to be necessary for sex determination and sex reversal.
基金This study was supported by National High Technology Development Program of China(863,Grant 2006AA100306)the Science Foundation of Shandong Province(032070104).
文摘Studies were conducted to determine the cause of the acute mortality of half-smooth tongue sole Cynoglossus semilaevis Günther juveniles in a fish farm in Jimo, Shandong Province, China, in June 2006. Gross signs of the diseased tongue sole included several petechiae and ecchymoses on the body and fin necrosis and hemorrhagic lesion at the base of the fin. Bacteria were isolated from kidney, liver and hemorrhagic lesions of the diseased tongue sole. Among 14 strains, SJ060621 was proved to be highly virulent to juvenile tongue sole with LD50 value of 〈1.0×10^5 colony forming units （CFU）mL^-1, while the remaining 13 were avirulent. Among the 16 antibiotics tested, SJ060621 was sensitive to gentamicin and nitrofurantoin. It was identified as Listonella anguillantm with conventional plate and tube tests in combination with API 20E analysis. 16S rRNA gene and partial HSP60 gene sequenceing analysis revealed that the strain was highly homologous with L. anguillarum. Examination of the infected musculature by electron microscopy indicated numerous bacteria and lots of macrophages containing phagocytosed bacteria. Histopathological investigations revealed severe necrotic degenerative changes in the infected organs. Indirect immunofluorescence assay （IFA） was employed to detect the location of occurrence of bacteria, and bacteria were found in aggregations in the inflammatory areas in musculature.
基金supported by the National Great Project of Scientific and Technical Supporting Programs (No. 2011BAD13B03)the program for Excellent Youth Foundation of Shandong Province (Grant No. JQ201009)the Major Project for Agricultural Application Technology Innovation of Shandong Province (No. 2013-136)
文摘Starving and re-feeding trials were conducted to evaluate the effects of starvation duration and recovery times on the growth performance and physiological characteristics of juvenile tongue sole Cynoglossus semilaevis, which included growth, body composition, intestinal morphology and digestive enzymes activities. The fish starved for one(D1), two(D2) and four(D4) days, respectively, were recovered for three(R3, R6, R12), seven(R7, R14, R28) and eleven(R11, R22, R44) folds of starvation days while the control fish were fed constantly. The experiment was conducted for 96 days. The fish individuals in D1R11, D2R14 and D2R22 caught up in weight with the control, indicating that complete compensatory growth existed in these fish individuals. The highest body weight gain and total specific growth rates were observed in D2R22. Food intake increased significantly in most treatments in comparison with that of the control except for D1R7 and D2R22(P < 0.05). Food conversion efficiency and apparent digest coefficient in D2R22 were significantly promoted, being higher than that of the control(P < 0.05). The activities of trypsin and lipase were found to be closely related to the growth performance. The activities of liver and hindgut trypsin, also midgut and hindgut lipase in D2R22 were significantly higher than those of the control(P < 0.05). The fold height(HF) of foregut and midgut increased significantly in D2R22, and HF decreased significantly in D1R3, D2R6 and D4R12(P < 0.05). On our findings, we may conclude that the optimum starving and re-feeding strategy is starving for 2 days and re-feeding for 22 days. And in this starving and re-feeding strategy, the compensatory growth could be mostly attributed to the promotion of food conversion efficiency and digestibility coefficiency.
基金This work was supported by grants from the Key Laboratory of Marine and Estuarine Fisheries,the Ministry of Agriculture(05-03-01)the Key Laboratory of Aquatic Genetic Resources and Aquaculmral Ecology(AGRA)Certified by the Ministry of Agriculture(KFT2006-5)+1 种基金Shandong Postdoctoral Science Foundation(200601001)China Postdoctoral Science Foundation(20060390999).
文摘A complementary DNA(cDNA) library was constructed from half-smooth tongue sole spleen. A long-read expressed sequence tag(EST) database was generated,containing 3100 cDNA clones,of which 220 clones were fully sequenced. A total of 1060 non-redundant simple sequence repeats(SSRs) were obtained from the cDNA library. An average of 5 kb sequence generates 1 SSR in the half-smooth tongue sole spleen cDNA library. The proportion of the SSR unit size was different in the cDNA library. The monomeric repeats(51.4%) are the most abundant class of SSR in the dataset. The dimeric,trimeric,tetrameric and hexameric re-peats are represented in decreasing proportions of 27.2%,16.0%,2.8% and 1.9%,respectively. The frequency of pentameric repeats was observed the least(only 0.7%) . Most of the monomeric and dimeric repeats are distributed in 3' and 5' un-translation region. If translation regions are considered merely,trimeric repeats are the highest,accounting for 57% of the total microsatellites.
基金supported by grants from State High-Technology R&D Project of China(863)(2006AA10A403)Shandong Genetic Improvement Key Project for Agricultural Organism,and Taishan Scholar Project of Shandong Province
文摘Two female-specific AFLP(amplified fragment length polymorphism)markers(named CseF464 and CseF136)were isolated by using one selective primer combination(E-AGC/M-CTG)from the genomic DNA of 20 females and 20 males of the half-smooth tongue sole Cynoglossus semilaevis.Both the markers were re-amplified,recovered from the agarose gels,cloned and sequenced.Bioinformatics analysis indicated that the length of the two markers were 468 bp and 134 bp,respectively,and the sequences showed no similarity to each other,as well as to the known sequences deposited in the GenBank database using BLASTn.Two pairs of SCAR(sequence characterized amplified regions)primers were designed based on the sequences of the two female-specific markers.Furthermore,PCR-based genetic sex identification method was developed in Cynoglossus semilaevis.A specific fragment was amplified in all females but not in any males by using these SCAR primers on the initial 20 female and 20 male individuals of Cynoglossus semilaevis.The feasibility of the two SCAR primer pairs was confirmed in additional 100 individuals(50 females and 50 males).This allowed for reliable,rapid molecular identification of genetic sex of the species,genetic mapping on the sex chromosomes and better understanding of the sex determination and sex differentiation in the half-smooth tongue sole.
基金supported by the National High Tech-nology Research and Development Program of China (No. 2006AA10A404)the National Natural Science Foundation of China (No. 30671624)
文摘Half-smooth tongue sole （Cynoglossus semilaevis） is a rare marine flatfish whose mature ovary and testis greatly differ in volume and weight. The length and weight of mature females are over twice greater than those of mature males. To obtain sufficient information on gonad differentiation and the relationship between gonad development and growth in the fish, we compared gene expression between the ovary and testis using suppression subtractive hybridization （SSH）. Testis cDNAs are subtracted from ovary cDNAs and are used to es- tablish an ovary testis-subtracted cDNA library. A total of 41 nonredundant clones are identified, including 20 known cDNAs, 9 unchar-acterized cDNAs （EST clones）, and 12 novel sequences. For selected genes such as ZPC, RacGAP, survivin, aquaporin, CPEB, O5, O15, and O18, gene expression patterns are analyzed by reverse transcriptase-polymerase chain reaction （RT-PCR）. The results confirm that these genes are only expressed in the ovary and not in the testis, or at higher levels in the ovary than in the testis. At the same time, expressions of certain genes such as ZPC, survivin, aquaporin, CPEB, and O15 are demonstrated to possess sexual dimorphism in the kidney or muscle, and spleen. The results suggest that these genes could play key roles not only in the ovary but in other female tissues as well.
基金The National Natural Science Foundation of China under contract No.31201981China Postdoctoral Science Foundation under contract No.2013M531658the Special Scientific Research Funds for Central Non-profit Institutes,Yellow Sea Fisheries Research Institutes under contract No.20603022012032
文摘Differential expression of genes is crucial to growth and development of fish. To select the appropriate genes for gene normalization during Cynoglossus semilaevis early developmental process, eight candidate reference genes （ACTB, B2M, EF1A, GADPH, RPL7, TUBA, UBCE and 18S） were tested for their adequacy by using quantitative real-time PCR. The results showed that the expression of all the examined genes exhibited tissue dependent variations in the mature C. semilaevis. EFIA was listed as the most stable reference among the 14 tissues by RefFinder. Furthermore, the recommended comprehensive ranking of the stability determined by RefFinder showed that 18S was the most stable gene during the early developmental stages （from oosphere to 90 days old） in this study. However, when divided the Ct value data of the above mentioned early developmental stages into two separate periods （embryo and post-hatching periods）, TUBA and 18S represented the most stable references of these two developmental periods, respectively. Consequently, the reference gene should be carefully and accurately chosen even for studies of the same species at various developmental processes. The relevant data may help in selecting appropriate reference genes for mRNA expression analysis, and is of great value in the studies of fish growth and development.
基金Supported by the Special Scientific Research Funds for Central Non-profit Institutes,Yellow Sea Fisheries Research Institute(No.20603022016004)the Central Public-interest Scientific Institution Basal Research Fund,YSFRI,CAFS(No.20603022017003)+2 种基金the National Natural Science Foundation of China(No.31530078)the Taishan Scholar Climbing Project Fund of Shandong of China,National Natural Science Foundation Projects(No.31802275)the Post-doctoral Applied Research Project Fund of Qingdao City(No.ZQ51201617023)
文摘The dmrt1 (doublesex and mab-3 related transcription factor 1) gene is considered to play an essential role in testis differentiation and development among metazoan species. As an economically important marine fish in China, Chinese tongue sole (Cynoglossus semilaevis) possess a ZW/ZZ sex-determining system, and the females usually grow two to four times bigger than males. Previous studies have confirmed that Z-linked dmrt1 gene is the male determining gene in C. semilaevis and TALENs-mediated knocking-out individuals showed increased growth phenotype. In order to investigate the function of dmrt1 regulatory regions and its potential application, we have cloned the promoter of C. semilaevis dmrt1. The acquired sequence consisted of a 5'-upstream sequence and a partial exon1;functional analysis showed that there were two positive regulatory regions in the promoter, as well as one negative region and one neutral region. These positive regions were then combined to obtain several newly constructed promoters. Both in vitro and in vivo analysis confirmed one of them (dmrt1-Δ3+Δ4) showed elevated promoting activity compared to the full-length promoter and could drive exogenous gene expression in tongue sole gonads. Our results will provide useful information for understanding the regulatory mechanism of dmrt1 gene during C. semilaevis sex determination, and the endogenous promoter will facilitate the transgenic research for analyzing sex- and growth-related genes.
文摘Examination of the food habits and seasonal variation of the stomach contents of adult tongue sole, Cynoglossus semilaevisGunther) taken in July 1982-July 1983 from Laizhou Bay and the Huanghe River estuary of the Bohai Sea showed Crustacea, bivalvia and small fishes comprised the main prey. Invertebrates such as polychaeta, cephalopoda, gastropoda, echinodermata and actiniaria were also intermittently found in them. They intensively fed all the year round (monthly feeding rate of over 80%). The main food items were Alpheus japonica, Alpheus distinguendus, Oratosquilla oratorio, Eucrate crenata and Carcinoplax vestitus, etc. In summer and autumn, the portion of bivalvia such as Cultellus attenuatus and Musculus senhousei increased steadily. From summer to winter, a stable proportion of small fishes such as Rhinogobius pflaumi and Setipinna taty was in the diet.
基金financially supported by the National Natural Science Foundation of China (Nos. 31570078, 31472273)the China Agriculture Research System (No. CARS-47-G03)the Taishan Scholar Climbing Program of Shandong Province, China
文摘The Chinese tongue sole(Cynoglossus semilaevis) is widely cultured in the coastal region of East Asia and has excellent economic value. However, the high albino rate of the breeding population has caused a significant loss to the aquaculture industry. To study the molecular mechanism of albinism, the present study used an albino Chinese tongue sole family to construct three simple sequence repeat(SSR) linkage groups, and draft a preliminary linkage map related to albinism. After albinism-related loci mapping, 18 albinism-related loci were detected under two models(containing 2407 genes) compared to the Chinese tongue sole genome. One of these loci, the tyrosinase related protein(tyrp2), which has been reported previously as an important gene regulating both eumelanin and phaeomelanin levels, was indicated to be the possible cause of albinism. Thirty-five Gene Ontology(GO) terms and 14 Kyoto Encyclopedia of Genes and Genome pathways were annotated via bioinformatic analyses. One GO term with protein tyrosine kinase activity, which contained 10 genes, was previously suggested to affect fish albinism. These results establish a foundation for further in-depth study of albinism in Chinese tongue sole.
基金The National Natural Science Foundation of China under contract Nos 31130057 and 31530078the Major Programs of Agriculture Seed Project of Shandong Province in China+1 种基金the Taishan Scholar Climbing Project of Shandong Province in Chinathe Startup Foundation for Doctors of Zhejiang Ocean University under contract No.22135010715
文摘Half-smooth tongue sole（Cynoglossus semilaevis） is a commercially important fish species. There were no reports about accurate genetic parameters of growth traits in C. semilaevis, despite efforts aimed at the culture of this species. Therefore, the main goal of this study was to estimate the parameters for the early growth traits（total length, body depth and body weight） of C. semilaevis based on the data obtained from 80 families. The trait of fish with pure white bottom or not（named as the trait of bottom color） was also analyzed. All the heritabilities estimated for the traits were medium, which varied from 0.210 to 0.362. Genetic correlations among growth traits were highly positive, varying from 0.913 to 0.959, indicating that selection of one of the three traits would result in correlated increase in the others. Also, genetic correlations between bottom color and growth traits were positive and varying from 0.241 to 0.353, suggesting that selection for the bottom color can be utilized to enhance the selection of growth traits. In addition, fish from the top performing 16 full-sib families were selected as broodstock, based on the above analysis and the comparison of family breeding value. This research provides an important basic material to implement selective breeding in C. semilaevis.
基金supported by the China Postdoctoral Science Fundation(No.2019M651472)the National Natural Science Foundation of China(No.31672642)the Key Laboratory of Mariculture of Ministry of Education,Ocean University of China(No.KLM2018009)。
文摘Pituitary adenylate cyclase activating polypeptide(PACAP)and growth hormone-releasing hormone(GHRH)play important roles in the GH/IGF growth axis in fishes.To determine whether epigenetic change is involved in the regulation of pacap and ghrh responses to low salinity stress in Cynoglossus semilaevis,the correlation between growth traits,DNA methylation status and gene expression level in low salinity(15,S15)and optimal salinity(30,S30)at day 7(D7)and day 60(D60)were analyzed.Results showed that exposure to low salinity for 60 days attenuated C.semilaevis growth rate.Under low salinity,DNA methylation level of pacap promoter increased in females and decreased in males at day 7,but inverted at day 60.Additionally,pacap expression was up-regulated in both males and females.The pacap promoter methylation level was higher and expression level was lower in female than in male.The results suggest that pacap promoter methylation level is negatively correlated to mRNA level and positively correlated to body weight,while gene expression level is negatively related with body weight.With the decrease of salinity,DNA methylation level of ghrh promoter and exon1,as well as its gene expression displayed minor changes.Overall,pacap gene seems to play an important role in fish growth,contributing to female growth superiority,while ghrh gene seems not pertinent under salinity stress.The results indicate that low salinity potentially affects fish growth through regulating DNA methylation in pacap promoter.This study expands the understanding of the molecular mechanism of how salinity modulates fish growth from the epigenetic perspective.
基金Supported by Qingdao Natural Science Foundation (No. 09-1-3-10-jch)"Taishan Scholar" Project Special Fundthe Yellow Sea Fisheries Research Institute Scientific and Research Fund
文摘The morphology and structure of the olfactory organ of Cynoglossus semilaevis Gunther are described. The oval olfactory sacs on both sides differ in size and in the number of lamellae, With those on the abocular side having smaller sacs and fewer lamellae than those on the ocular side. On the ocular side, the average ratio of sac length to eye diameter is 2.1 （i.e.〉1） with an average of 91 lamellae, while on the abocular side, the values were 1.7 （i.e.〉1） and 69, respectively. In addition, the surface morphology varies in different parts of the lamella. The frontal part, near the anterior nostril, is a non-sensory margin with cilia-free epidermal cells. Within this is an internal ciliated sensory area, which is intercalated with ciliated receptor cells and a few ciliated non-sensory cells. Additionally, some dense ciliated non-sensory cells make up a non-sensory area, which also contains cilia-free epidermal cells distributed in patches. In the rear of the olfactory sac near the posterior nostril, the lamellae differ in morphology from those of the frontal olfactory sac but are similar in having few ciliated receptor cells. In other words, the surface of the lamellae in the rear part of the olfactory sac is mainly non-sensory. At present, four types of lamellae （~ E IlIand IV） have been recognized in relation to the pattern of the sensory epithelium. In this study, the frontal and rear lamellae resembled types I and IV, respectively, but are referred to as types r and IV because they are slightly less developed. Data on the ratio of length of lamellae to eye diameter, number of lamellae and the type of surface pattern of the lamellae show that the development of the olfactory system of C. semilaevis facilitates prey capture.
基金supported by the National Great Project of Scientific and Technical Supporting Programs of China (Grant No. 2011BAD13B03)]the Program for Excellent Youth Foundation of Shandong province (Grant No. JQ201009)the Public Science and Technology Research Funds Projects of Ocean, State Oceanic Administration of the People’s Republic of China (Grant No. 200905020)
文摘Effects of the amplitude(± 2, ± 4, ± 6, and ± 8) and frequency(2, 4, and 8 d) of salinity fluctuation on the body composition and energy budget of juvenile tongue sole(Cynoglossus semilaevis) were investigated in a 64-d experiment. Results showed that the amplitude and frequency of salinity fluctuation had significant interaction and both substantially affected the final weight and specific growth rate of juvenile tongue sole. The tongue sole exhibited better growth in treatments with moderate amplitude and frequency of salinity fluctuation(amplitude ± 4–6; frequency 4–8 d) than in other treatments and the control. In terms of energy budget, salinity fluctuation strongly affected the proportions of energy components, including those deposited for growth and lost in respiration, feces, and excretion. Moderately amplitude and frequency of salinity fluctuationg that favored the growth of tongue sole partitioned more energy for growth and less energy for metabolism than the constant and other amplitude and frequency of salinity fluctuation. Average energy budget for tongue sole at moderately fluctuating salinity was determined to be 100C(food) = 30.92G(growth) + 10.30F(feces) + 6.77U(excretion) + 52.01R(respiration). Energetic advantage at moderately fluctuating salinity, including increased energy intake, high assimilation efficiency, reduced metabolism expenditure, and more energy partitioned into growth, might account for the enhancement of tongue sole growth. Commercial farmers are recommended to rear juvenile tongue sole with moderate salinity fluctuations for better growth performance of this species.
基金Supported by the Open Funds of Jiangsu Key Laboratory of Marine Biotechnology, Huaihai Institute of Technology (No. 2007HS015)the Shandong Post-Doctoral Science Foundation (No. 200802039)the China Postdoctoral Science Foundation (No. 20060390999)
文摘The genetic diversity of wild and hatchery populations of half-smooth tongue sole Cynoglossus semilaevis, based on observation of amplified fragment length polymorphism (AFLP) was described. Two hundred individuals from four wild populations, Laizhou (LZ), Weihai (WH), Qingdao (QD), Rizhao (RZ), and one hatchery population, Mingbo (MB), were screened using eight different AFLP primer combinations. A total of 384 loci were screened in the five studied populations. 48.4%, 51.3%, 50.7%, 49.3% and 45.8% of these loci were polymorphic among the individuals tested in the LZ, WH, QD, RZ and MB populations, respectively. The number of polymorphic loci detected by single primer combinations ranged from 17 to 35. The average heterozygosity of the LZ, WH, QD, RZ and MB populations was 0.072, 0.093, 0.092, 0.090 and 0.063, respectively. The WH population showed the highest genetic diversity in terms of total number of AFLP bands, total number of polymorphic bands, average heterozygosity and percentage of low frequency (0-0.2) polymorphic loci among all the populations, while the LZ population was the lowest among the wild populations. Compared with the wild populations, the hatchery population showed a low genetic viability.
基金Supported by the National High Technology Research and Development Program of China(863 Program)(No.2012AA10A403-2)the Taishan Scholar Project of Shandong Province of China
文摘Phenotypic and genetic parameters for growth-related traits in the half-smooth tongue sole, Cynoglossus semilaevis, were estimated in 22 full-sib families produced by normal and neo-male breeding stocks. As phenotypic males with female genotypes, neo-males are harmful in C. semilaevis aquaculture because they reduce overall production. The present study evaluated the difference in the growth-related traits： total length （TL）, body weight （BW） and square root of body weight （SQ_BW） at the age of 570 days between normal and neo-male offspring （neo-males used as male parents）. The difference in the proportion of females between normal and neo-male offspring was also assessed. Based on the linear mixed model, restricted maximum likelihood （REML） and best linear unbiased prediction （BLUP） were used to estimate various （co）variance components and estimated breeding values （EBVs） of growth-related traits. As a result, all the mean values of the three studied traits were significantly larger in normal offspring than in neo-male offspring. Additionally, the female proportion was significantly larger in normal offspring than in neo-male offspring. Heritability was 0.128＋0.066 2 for TL, 0.128-4-0.065 5 for BW and 0.132~0.062 9 for SQBW, all of which were low level heritabilities. The correlation coefficients of EBVs and phenotypic values of the target traits were 0.516 for TL, 0.524 for BW and 0.506 for SQ_BW, all of which were highly significant （P〈0.01）. Genetic correlations among TL, BW and SQ_BW were positive high （0.921-0.969） and higher than those of phenotype （0.711-0.748）, both of which had low standard errors （0.063-0.123 for genotype, and 0.010-0.018 for phenotype）. Compared with normal offspring, neo-male offspring have lower breeding values for each studied trait through EBVs comparison. Therefore, neo-male offspring should not be used as broodstock in a C. semilaevis breeding programs.
