Abstract:gene is a critical regulator of developmental timing events of the larval-to-adult transition. Here, was identified by a stem-loop RT-PCR. The precursor of was cloned and was proven to be highly conserved among different species. Quantitative analysis revealed that the expression levels of were generally variably enhanced during the first five metamorphic stages and peaked during the late metamorphic stages (36 dph). At To study the effects of ^{) were used to treat , indicating that -UTRs) of 29 mRNAs were possible target sites matche. These mRNA targets played key roles in diverse biological processes: development, cell proliferation, signal transduction, virus immune response, and signaling pathways. These re sults suggested that played an essential role in regulating the developmental timing of metamorphosis.}

Abstract:Insulin-like growth factor I (IGF-I) is an important regulator of growth and development in vertebrates, and its biological actions are by binding to membrane-specific IGF-I receptors (IGF-IRs). Therefore, the analysis of expression can help to further elucidate the role for IGF in the regulation of developmental processes. In this study, the expression patterns of and its receptor genes during the embryonic development of Japanese flounder () were analyzed by fluorescent real-time PCR using embryos at different developmental stages. We observed that maternal transcripts of were present in early embryos and that their expression is developmentally regulated at different embryonic stages. A few transcripts are gradually increased from the eye lens formation stage to the pre-hatching stage. exhibit distinct temporal expression patterns during embryonic development. , and these appear at the transcripts are abundantly expressed at the gastrula stages and maintain a high level at the neurula, By contrast, the considerable transcripts of transcripts decrease significantly following . This indicates that the two IGF-I receptors might play different functional roles during

Abstract:The objective of this study is to screen the differential gene expression in response to a pathogenic infection in the skin of fish, and to provide a basis for understanding the fish skin immune mechanism at the molecular level. The immune response in the skin was analyzed by using induced zebrafish as a model, and applying the affymetrix zebrafish cDNA microarray hybridized to the skin tissues. Total RNAs were isolated from the skin tissues of adult fish, labeled with biotin, and hybridized to zebrafish cDNA gene chips. The expression profiles from the hybridization to 15 617 genes in the zebrafish cDNA array were analyzed by the GeneChip Operating Software (GCOS1.4). Out of 15 617 genes in zebrafish cDNA chips, a total of 175 was identified to be significantly expressed in the skin tissues, of which 150 were up-regulated and 25 were down-regulated. Among the 150 up-regulated genes, the functions of 91 genes were known and 59 were unknown. Furthermore, by using the Gene Ontology (GO) method the differential expression genes could be categorized into 13 functional groups, and some of them are considered as potential candidates in the fish skin immune response. Thus, several genes related to immune response in the skin were identified, including major histocompatibility complex class I genes (UEA, UFA), complement component (C1q, C7-1), lectin (HBL3, LGALS1L3), early growth response 1 (EGR-1), tumor necrosis factor superfamily (TNFSF10L4), coagulation factor V(F5), transferrin-a (TF-a), and several proteases. The Affymetrix zebrafish cDNA microarray is useful for identifying the functional genes involved in the skin immune defense of fish: that is, MHC I, complement, lectin, and proteases. However, future analysis of the function of these genes may contribute to an understanding of the mechanisms of pathogenesis

Abstract:S-Adenosyl-L-methionine(SAM)is the most common methyl donor in a multitude of cellular methylation reactions. Numerous methyltransferases transfer the methyl group from SAM to their respective biological acceptors, forming S-adenosyl-L-homocysteine(SAH). SAH is hydrolyzed to adenosine and L-homocysteine by S-adenosyl-L-homocysteine hydrolase(SAHH, EC 3.3.1.1). SAHH is an essential enzyme in all living cells, and has been explored as a potential drug target for many bacteria and parasites. The inhibition of SAHH activity can result in the accumulation of SAH and reduce the S-adenosylmethionine(SAM):SAH ratio in cells. In that case, SAHH can act as a potent feedback inhibitor, blocking the SAM-dependent methylation that is required for the metabolism of a wide variety of biological compounds such as nucleic acids, proteins, phospholipids, and other small molecules. SAHH is found in animals, plants, fungi, and other microorganisms. Antarctic ice microalgae with special characteristics to withstand the extreme environment characterized by low temperatures and ice, high levels of dissolved oxygen, and strong seasonal changes in light intensity have been investigated in recent years. To further understand the intrinsic mechanisms by which the Antarctic sea ice alga sp. ICE-L responds to ecological and environmental factors, we cloned and analyzed its SAHH. A cDNA encoding S-adenosyl homocysteine hydrolase(designated as ICE-LSAHH)was cloned from this alga by RT-PCR and RACE-PCR methods. The ICE-LSAHH full-length cDNA sequence was 1844 bp, including a 5-terminal UTR of 344 bp with a poly(A)tail, and an open reading frame(ORF)of 1461 bp encoding a polypeptide of 487 amino acids. The predicted molecular weight(MW)of ICE-LSAHH was 53 kD with an estimated pI of 5.16. Using software, it was predicted that the ICE-LSAHH protein did not contain a signal peptide or a transmembranous region, suggesting that it is not a secretory protein. To further analyze the evolutionary relationship among SAHH enzymes, a molecular phylogenetic tree was constructed using ClustalX 2.0 and Mega 5.0 software. The reliability of branching was tested by bootstrap re-sampling(1 000 pseudo-replicates). In the phylogenetic tree, members of the SAHH protein formed clear subgroups of plants, animals, algae, and bacteria. The . Sequence analysis with the BLAST algorithm showed that the ICE-LSAHH gene shared 62%–85% sequence identity with other SAHHs. The highest sequence identity was 85% with the SAHH gene of . Amino acid sequence alignment between ICE-LSAHH and other SAHHs showed that the ICE-LSAHH protein exhibited high sequence homology with other SAHHs. The three-dimensional structure of ICE-LGPx was determined using SWISS-MODEL workspace and software. The 3D molecular model showed that the ICE-LSAHH subunit has three domains: a substrate-binding domain, an NAD-binding domain, and a C-terminal domain. In conclusion, Chlamydomonas sp. ICE-L.

Abstract:The sequence-related amplified polymorphism (SRAP) molecular marker technique and BSA were used to Fenneropenaeus chinensis. The markers, which were based on differences between sensitive and tolerant samples, will be used to provide information and tools for the protection of the germplasm resource and for molecular marker-assisted breeding. We used 110 SRAP primers to screen for molecular markers. We selected 77 and 102 SRAP primers to screen ammonia nitrogen and pH-BSA gene pools, respectively. According to the frequency and pattern of bands in the samples, six markers associated with resistance to high ammonia nitrogen were selected; one from sensitive samples and five from tolerant samples. These markers ranged in length from 166 to 571 bp. Similarly, seven markers associated with resistance to high pH were selected; two from sensitive samples and five from tolerant samples. These 13 genetic markers were cloned into the pMD-18T vector, transformed into TOP10, and sequenced. The sequence data has been submitted to GenBank under the accession numbers GU570681–GU570693. Sequence and BLAST analyses showed that there was low similarity (<15%) between the markers and known functional genes, indicating that these markers are tightly linked to stress resistant traits but are not functional genes. Further research has been carried out to validate these results. These markers can be used to screen for stress resistance traits in

Abstract:) was constructed to investigate the function of immune-related proteins and to gain insight into their mechanisms of interaction. The titer of this original library was 1.6×10⁶ CFU/ml. Most of the fragments PCR-amplified from single colonies were larger than 500 bp, with an average length of 1.5 kb. We randomly selected and sequenced 115 expressed sequence tags. The capacity of the amplified library was approximately 1.8×10¹² CFU. After transformation into yeast cells, the transformation efficiency was 3.6×10⁵ CFU/μg, and the capacity was 5.4×10⁶ CFU. The successful construction of this yeast two-hybrid library provides an effective tool to elucidate mechanisms of immunity, especially signaling pathways, in this flounder species.

Abstract:) grow faster than males. Therefore, farming all-female progenies could maximize profits from cultured fish. In the present study, diploid gynogenesis was induced by activating flounder egg development with UV-irradiated (72 mJ/cm²) sperm for 3 min in sea water, and then subjecting the eggs to a cold-shock (0–2) treatment for 45 min. Cold shock was used to prevent extrusion of the second polar body. In the control treatments, one or more of these steps was omitted to separately assess the effectiveness of UV irradiation and cold shock. When the initial treatment was applied 3 min after hatching (treatment duration, 45 min), the fertilization rate of eggs activated by UV-irradiated heterologous sperm was (37.2 ± 5.1)%, the malformation rate of newly hatched larvae was 8.3 ± 2.5)%, and the hatching rate was up to (9.4 ± 0.71)%. Flow cytometry and chromosome karyotyping were used to examine the ploidy level of larvae experienced to the cold-shock treatment. All of the gynogenetic larvae were diploid (2n = 48), and no haploid or aneuploid phenomena were detected. The duration of hatching of haploid embryos and gynogenetic embryos was significantly different from that of control normal embryos. There were no significant differences in the morphological index between gynogenetic diploids and normal larvae (>0.05). All of the haploid larvae (100%) showed abnormal external morphology (<0.05) while normal diploid larvae and gynogenetic diploid larvae showed normal morphologies. In summary, these methods resulted in successful diploid gynogenesis in southern flounder using heterologous sperm. This technique could serve as a useful tool to produce monosex progenies of southern flounder.

Abstract:this study was to investigate the effects of starvation, refeeding, and feeding frequency on the growth and digestive enzyme activity of rock bream ( In the starvation and refeeding experiment, the body weight, proteinase ( activities decreased with increasing starvation time. There were significant differences in body weight and pepsin activity between the control group and the group starved for 6 days. After 9 days of starvation, the lipase activity was significantly lower than that of the control group. Theactivity fluctuated throughout the experimental period. After refeeding, the fish body weights and specific growth rates (SGRs) of all groups (except S3: starvation for 3 d and refeeding for 27d) were significantly lower than those of the control group. However, there were no significant differences in body weight and SGR between the S3 group and the control. The proteinase and lipase activities increased after recovery feeding. There was no significant difference in proteinase activity between the starved groups and the control. However, the lipase activity after a starvation (9–12 days) did not return to the level of the control group. five experimental groups were fed 0.5, 1, 2, 3 or 4 times per day in a 30-day trial. The results showed that SGR tended to increase with increased feeding frequencyHowever, there were no significant increases in SGR and digestive enzyme activity at higher feeding frequencies (more than twice per day). In conclusion, the results of this study indicate that starved for 3 days had fully compensatory growth ability, and

Abstract:Pallas in the Yalu River and its tributaries is a promising and emerging aquaculture population in northeast China. However, the wild population of in the river has declined recently. We studied embryonic development, the effects of starvation, and the point of no return (PNR) of Yalu River and its tributaries. Three batches of . Mature eggs were spherical, ecru, and (1.94±0.13) mm in diameter. Fertilized eggs were spherical, adhesive, and (3.07±0.12)  mm in diameter.℃ normal embryonic development to progress through , cell division, blastula, gastrula, neurula, and organ formation stages. Newly-hatched larvae were (8.07±0.27) mm in total length and the yolk sac was (0.55±0.12) mm³ in volume. The yolk sac had absorbed completely at 6 days post-hatch (dph). The total length and body weight of the control group (feeding 2 times everyday ) had increased to(12.58±1.03) mm0.010 8±0.002 2) g, respectiveand (=0.982 6) and body weight (=0.963 6) in experimental groups were both positively correlated to dph in the control group. In contrast, both total length and weight of the starved larvae began to decrease after absorption of the yolk sac at 6 dph, declining to (9.32±0.47) mm and (0.0022±0.0005) g, respectively, at 13 dph. Control larvae started to feed at 5 dph, at which time the feeding rate was 65%; 100% were feeding at 7 to 10 dph. Starved larvae suffered from PNR at 12−13 dph, and all died by 14 dph. Understanding embryonic development and knowing the effects of starvation will be important to artificially propagating and in fish ecology and fisheries biology. Our research will play a key role in artificially propagating large numbers of individuals to augment the wild population and its recruitment deficits.

Abstract:Scophthalmus maximus. We investigated the causes of albinism in cultured turbot by constructing 32 full-sib turbot families using standardized larval-rearing in 2009. We measured weight and documented the morphology of 16 full-sib families (including 6 pairs of half-sib families) with higher rates of albinism 85 days post hatching (dph). We compared the morphology of albino juveniles and normal juveniles in every F₂ family. In addition, we selected a fast growing family and three high-body type families as candidates for a selective breeding program. The skin pigmentation pattern could be classified into 3 types: albino, partial albino, and normal, in which the partial albino was classified as being within the range of albinism. The albino rate of every F₂ family was between 17.2 and 86.7%. There was a significant difference in the rate of albinism among half-sib families, which was likely caused by maternal inheritance and ovular quality. We also found a significant difference in total length, body length, total height, body height, and total weight (<0.05) between albino and normal juveniles in families C, Hand R. In addition, total height and body weight were significantly different among the 16 full sib families (<0.05). There was no significant difference in any of the measures between albino and normal juveniles within the same family, with the exception of families H and R. In summary, there were no significant differences in growth rates and body shape between albino and normal juveniles. Our results suggest that although genetics play a role in albinism, it is not the determining factor.

Abstract:Embryonic development is a critical period that determines the quality of juvenile fish. Our objective was to determine the mechanisms modulating metabolism during embryonic developmentA number of key enzymes play an important role during the process of embryonic development, including MDA) content reflects the level of lipid peroxidation, which results from the reduction of antioxidant defenses. healthy embryos at several stages following fertilization and measured LSZ and LSZ and CAT activity decreased gradually during development of the embryos. LSZ activity was lowest after 96 h, i.e. (0.450±0.064) U/mg. Furthermore, LSZ activity was lower at 96, 120, and 144 h than that at 24 h (<0.05). CAT activity also decreased significantly after 96, 120, and 144 h (<0.05), relative to levels in 24 h old embryos. In contrast, MDA content increased gradually throughout embryonic development, with the largest increase occurring after 96 h. MDA content was significantly higher after 120 and 144 h than after 24 h (<0.05). In summary, LSZ and CAT activities gradually decreased during development and were generally significantly lower than initial levels by 96 h. This decrease is likely due to metabolism of maternal enzymes and the poor ability of the embryos to synthesize new enzymes. The decrease in CAT activity likely resulted in a surplus of reactive oxygen species, leading to the accumulation of MDA. Our results suggest that the embryos were subject to certain level of oxidative stress. Furthermore, it appears that the first 96 h of embryonic development is critical in determining the future of embryonic development. Therefore, goldfish embryos should be handled with care during this period to minimize stress. The duration of embryonic development should also be maintained within a suitable range by manipulating temperature because the extension of developmental time will result in oxidative stress and increase the risk of mortality in the embryos.

Abstract:). esponse surface methodology (RSM) based on a two-factor Central Composite Rotatable Design (CCD) of experiments to optimize the level of these two factors within the range 18–37 and 0–16. The linear and quadratic effects of temperature and salinity had a significant effect on SGR and survival (). larval growth and survival increased then decreased with as temperature or salinity increased. In addition, the interaction between temperature and salinity had a significant effect on growth and survival (). SGR and survival were higher at 18–20 between salinities 5 and 7. In contrast, SGR and survival were higher at ~salinity 4 at between 35–37yielding values of 0.979 6 and 0.982 1 (), and had good predictive value. Temperature had a great influence on SGR survivalSolving the regression equation for temperature equal to 29.1and salinity equal to 5.4, the optimum predicted value for specific growth rate and survival is 10.08%∙d^{desirability is 0.973). Thus, our data suggest the growth and survival of tilapia larvae can be improved by rearing the species at an optimal combination of temperature and salinity}

Abstract:Antimicrobial peptides have attracted considerable attention because of their potential use for therapy and prophylaxis. We evaluated the effects of dietary supplementation with recombinant antimicrobial peptide on growth, immunity, and performance in the protest test in 10.68g±0.53g. The fish were divided into six treatment groups and fed experimental diets containing cell numbers, and catalase activity were significantly higher in the groups supplemented with 5 and 10 mg/kg compared with the control. The specific growth rate was highest in the group given 5 mg/kg RAP. Liver lysozyme activity were significantly lower in the group given 50 mg/kg RAP than in the control. Supplementation with 100 mg/kg florfenicol increased the number of red blood cells, but had no effect on the other indexes. Following infection with , the death rate was significantly lower in groups fed between 5–20 mg/kg RAP than in the control. The survival was highest in the group fed 5 mg/kg. Our results suggest that dietary supplementation with appropriate levels of antimicrobial peptide improves growth, immunity, and performance in the protest test . However, increasing the dose can lead to negative effects on growth and enzyme activity. Therefore, we recommend that supplementation should not exceed 20 mg/kg. Our results provide insight into the proper application of recombinant antimicrobial peptides to

Abstract:on growth, digestive enzyme activity, and non-specific immunity in hybrid sturgeon ( ♀) juveniles. The hybrid sturgeon fingerlings (=225, initial average weight: 10.34 g±0.19 g) were randomly assigned to 5 groups (3 replicates/group, =15 per replicate) that were fed one of five diets containing 0 (control), 0.05% (group ), or 0.5% (group for 30 d. Growth was improved in hybrid sturgeon fed a diet containing 0.25% . Weight gain and the specific growth ratio increased by 54.31% and 28.61%, respectively, compared with the control group (<0.05). The feed conversion ratio was 36.02% lower than in the control group (<0.05). The activities of amylase, lipase, and protease were higher in the intestine in all groups compared with the control group. Furthermore, activity was higher on day 15 than on day 30. Digestive enzyme activity was highest in group and was significantly higher than in the control group (<0.05). Similarly, lysozyme, superoxide dismutase, and alkaline phosphatase activity and total antioxidant capacity were higher in group III than in the remaining groups on day 15 (<0.05). The indices of non-specific immunity were lower on day 30 than on day 15 in group III and were not significantly different from the control group to the diet increases digestive enzyme activity and non-specific immunity and promotes the growth of hybrid sturgeon juveniles. The benefits were most pronounced at a level of 0.25% with repeated supplementation every 15 d.

Abstract:can develop to physiology maturity and exhibit strong secondary sex characters. Conversely, the gonads of female triploid rainbow trout are typically underdeveloped and are characterized by a We evaluated the effect of chromatosome polyploidy on the reproductive potential of triploid male rainbow trout. We obtained hybrid embryos by artificially inseminating diploid female trout with sperm from triploid male rainbow trout. The diploid females were obtained from a superior strain of two generation family selective breeding. The male triploid was obtained by artificially inducing triploidy using heat shock. We monitored the development of the hybrid embryos and measured their DNA content (ploidy) using flow cytometry. The fertility, eyed rate, and hatching rate of hybrid embryos were significantly lower than the control diploid embryos (fry died during early development or within a short time after hatching. There was considerable variation in the DNA content of the hybrid embryos. The to 3n and their DNA content was ~2.5 times that of the control embryos. The ploidy of the remaining 16% ranged from 3n to 4n. Our results suggest that karyoplasm between the gametes of male triploid and femalediploid rainbow trout. We hypothesize that the hybrid embryos do not survive because of disorders of gene expression and regulation.

Abstract:We evaluated genetic diversity and differentiation among five wild populations of the swimming crab () using eight polymorphic microsatellite loci. We collected crabs from Zhoushan (ZS), Haizhou Bay (HZ), Huichang (HC), Laizhou Bay (LZ), and the mouth of the Yalu River (YL). We isolated 72 alleles from eight loci among the five populations. The number of alleles ranged from 6 to 12 and the average number of alleles () were 9.0 and 5.467 7, respectively. The mean PICvalue for the eight microsatellite loci was 0.696 7. The expected heterozygosity () of each population was as followsHZ (0.741 5), and ZS (0.728 3). The observed heterozygosity () was between 0.648 1 and 0.760 4. Six loci deviated significantly or very significantly from Hardy-Weinberg equilibrium. The genetic distances among populations ranged from 0.245 1 to 0.517 9. The UPGMA tree suggested that there were two different groups: one being composed of YL and LZ, and the other of HC, HZ and ZS. The values ranged from 0.054 8 to 0.108 3, suggesting that the degree of differentiation was moderate among the five wild populations (0.05<<0.15).

Abstract:Marine ecosystems, particularly the structure of fish assemblages are increasingly affected by human activity.We evaluated the structure and distribution of fish resources using data collected by trawl surveys in May and October of 2006 in the Yellow Sea off Shandong (35º00E). We collected samples at 45 sites and standardized the survey data using the sweep area and capture coefficient. The capture coefficient was set to 0.55 for pelagic fish, 0.35 for demersal fish, and 0.25 for benthic fish. The abundance index was much higher in the coastal waters than in the deeper, offshore waters in spring. During this time, most species migrate to the coastal regions to spawn. In addition, winter-spawning species, such as pacific sandeel (), were still feeding in the coastal waters during the time of the surveys. In autumn, the abundance index was slightly higher in the coastal waters than in the offshore areas. The highest abundance index was measured in Haizhou Bay, both in spring and autumn. We collected a total of 61 species, 50 in spring and 50 in autumn. The structure of fish resources was analyzed based on economic value, habitat layer, and temperature-adapted components. The lower-valued species were dominant in spring and autumn. The lower-valued species constituted 91.0% of the biomass in spring and 80.9% in autumn. The demersal fish were dominant in spring (76.7% of the biomass) whereas pelagic fish, dominated in autumn (75.1% of the biomass). The biomass was dominated by cold-water species (75.0%) in spring and warm-water species (50.1%) in autumn.Engraulis japonicas), fang’s blenny (). Conversely, the assemblage was dominated by Sardinella zunasiThrissa kammalensis), silver pomfret, gizzard shad smallhead hairtail, spotted mackerel, and scaly hairfin anchovy in autumn. We used the Normalized Biomass Size Spectra (NBSS) to compare the community composition between months and years. Species that contributed <0.01% to the total biomass were excluded. The slope was regressed by log₂ (total biomass of every weight class/10) to log₂ (upper limit of average individual weight class). The NBSS slope was <1 in both spring and autumn, suggesting the biomass decreased as individual body weight increased. The average individual body weight was 2.36 g/individual in spring and 3.34 g/individual in autumn. The proportion of species whose average individual body weight was <10 g was 95.74% in spring and 82.09% in autumn. Compared with the 1980s, we conclude that: 1) The low-valued species are more dominant, 2) though there has been a partial recovery in the fishery, the larger, high value species have not recovered at the same rate, and 3) the dominant species has changed significantly due to an increase in the number of fang’s blenny. Given our results, we propose an earlier beginning to the closed fishing period during summer.

Abstract:Our objective was to evaluate ecosystem status before and after fishery enhancement. We analyzed the feeding habits, food consumption, and trophic level of the species constituting 90% of total biomass in bottom trawl surveys conducted in May and August of 2010. We compared the traits of the five dominant species (by total biomass) with those collected in 1985 and 2000. In addition, we evaluated decadal-scale variation in the mean TL of the fish community in the north Yellow Sea. The fish community in the north Yellow Sea was dominated by nine species, though these differed between May and August. The most dominant species in May included small yellow croaker , half-fin anchovy Cleisthenes herzensteini, Pacific cod . Conversely, in August the fishery was dominated by anchovy , small yellow croaker, elongate eelpout, and Pacific cod. Thus, the assemblage in May was characterized by a lack of nektivores, a decrease in the proportion of generalist predators, and an increase in the proportion of zooplanktivores relative to August. The mean trophic level of the fish community was 3.75 in May and 3.57 in August. The primary prey groups included euphausiids, copepods, hyperiid amphipods, crustacea larva, shrimps, ophiuroidea, bivalvia, polychaeta, and other fish species. We estimated the fish community consumed 0.5 million tons and 19.6 million tons of these prey items in May and August, respectively. Fish and shrimp were the dominant prey groups in May, accounting for 46.9% and 39.2% of the total food consumption, respectively. Similarly, fish, shrimp, and zooplankton were the dominant prey groups in August, accounting for 33.9%, 31.4%, and 30.8% of the total food consumed, respectively. The primary prey species were , small yellow croaker, in May. Consumption of these species equaled 0.3 million tons, accounting for 65% of the total food consumption. The primary prey species in August were Calanus sinicus, and anchovy. Consumption of these species equaled 12.4 million tons, accounting for 62.9% of the total food consumption. Thus, as in the central and southern Yellow Sea, , small yellow croaker, and anchovy were the most important prey species in the north Yellow Sea. The mean trophic level of fish community declined from 4.26 in 1985 to 3.66 in 2010 in the north Yellow Sea,. This decrease was more rapid than in the Bohai Sea and central and southern Yellow Sea and was caused by a shift in the dominant species in the fish community. The percentage of nektivores decreased concomitantly with an increase in generalist predators between 1985 to 2010. The rate of change in trophic level has decreased from 0.28 decade^{between 2000 and 2010, but has remained higher than the global rate. Given this, we recommend continuing efforts to enhance the fishery.}