Carp Research Articles

Identification, Molecular Characterization and Expression Pattern Analysis of SoxD Subgroup Genes in Yellow River Carp (Cyprinus carpio)

Identification, Molecular Characterization and Expression Pattern Analysis of SoxD Subgroup Genes in Yellow River Carp (Cyprinus carpio)

Identification of suh gene and evidence for involvement of notch signaling pathway on gonadal differentiation of Yellow River carp (Cyprinus carpio).

The suh gene is crucial in Notch pathway and regulates mammalian gonad development. In this study, the sequences of suh1 and suh2 genes in Yellow River carp (Cyprinus carpio) were verified. The partial 5'-flanking regions of suh1 and suh2 were analyzed and several potential transcription factor-binding sites were identified. Phylogenetic, gene structure, and chromosome synteny analyses revealed that carp suh1 and suh2 were orthologs and homologous to vertebrate suh. Investigation of the expression profiles of suh1 and suh2 with qPCR showed that these genes were abundant in the brain and gonad of carp, with suh1 exhibiting sexual dimorphism expression pattern in gonad. To study the relationship between gonad differentiation and Notch signaling, primordial gonads were exposed to DAPT, an inhibitor of Notch signaling, in vitro and in vivo. The results revealed a significant downregulation of suh1 and other Notch genes in vitro. In addition, expression of male-biased genes, such as amh, dmrt1, etc., was downregulated, whereas that of female-biased genes, such as foxl2, gdf9, etc., was upregulated. When the primordial gonads were subjected to long-term DAPT exposure, an increased proportion of ovary and delay in testis development were observed. These results suggest that suh gene may have a conservative function between teleosts and mammals. Furthermore, Notch signaling was found to be involved in gonad differentiation in Yellow River carp, and DAPT was noted to inhibit and enhance the expression of male- and female-biased genes, respectively, and induce the increase in number of females.

Effects of triclosan (TCS) on hormonal balance and genes of hypothalamus-pituitary- gonad axis of juvenile male Yellow River carp (Cyprinus carpio)

Triclosan (TCS) is a broad spectrum antimicrobial agent which has been widely dispersed and determinated in the aquatic environment. However, the effects of TCS on reproductive endocrine in male fish are poorly understood. In this study, male Yellow River carp (Cyprinus carpio) were exposed to 0, 1/5, 1/10 and 1/20 LC50 (96 h LC50 of TCS to carp) TCS under semi-static conditions for 42 d. Vitellogenin (Vtg), 17β-estradiol (E2), testosterone(T), gonadotropin (GtH), and gonadotropin-releasing hormone (GnRH) levels were measured by enzyme-linked immunosorbent assay (ELISA). Meanwhile, we also examined the mRNA expressions of aromatase, GtHs-β, GnRH, estrogen receptor (Er), and androgen receptor (Ar) by quantitative Real-time Polymerase Chain Reaction (qRT-PCR). TCS induced Vtg levels of hepatopancreas, E2 levels of serum, and inhibited Ar and Er mRNA levels, suggesting that the induction of Vtg production by TCS was indirectly caused by non-Er pathways. TCS-induced Vtg levels by interfering with the reproductive axis at plenty of latent loci of male carps: (a) TCS exposure increased the aromatase mRNA expression of hypothalamus and gonad aromatase, consequently increasing serum concentrations of E2 to induce Vtg in hepatopancreas; (b) TCS treatment changed GtH-β and GnRH mRNA expression and secretion, causing the disturbance of reproductive endocrine; (c) TCS exposure decreased Ar mRNA levels, indicating potential Ar-mediated antiandrogen action. These mechanisms showed that TCS may induce Vtg production in male carp by non-Er-mediated pathways.

Fine mapping of growth-related quantitative trait loci in Yellow River carp (Cyprinus carpio haematoperus)

Genetic linkage map and quantitative trait loci (QTL) mapping are powerful tools for genetic analysis of a series of economic traits in aquatic animals. Yellow River carp (Cyprinus carpio haematoperus), one of the famous common carp strains, is widely cultured in northern China, however, genetic and genomic bases of growth-related traits have been rarely studied in this carp strain. In present study, an F2 family of Yellow River carp (8months old) was used for constructing genetic linkage map and detecting potential QTL for growth traits, including total length (TL), body length (BL), body height (BH), head length (HL) and body weight (BW). A high-density genetic linkage map was constructed mainly based on 2b-RAD technology, with 6230 SNPs and 65 SSRs assigned onto 50 linkage groups, covering 98.2% of the Yellow River carp genome (average 0.59cM/marker). Comparative mapping showed high levels of syntenic relationship between our map and the genomes of two cyprinid fish (Denio rerio and Ctenopharyngodon idellus), while a lower synteny was detected between our map and C. c. carpio genome. Twelve chromosome-wide and two genome-wide growth-associated QTL were detected in our study, with the phenotypic variance explained ranging from 11.9% to 16.2%. These QTL were scatteredly distributed on 8 LGs of our sex-averaged linkage map. Fifteen candidate genes (e.g. INSIG1, 3β-HSD, HGF) were identified by BLAST searching the sequences of QTL-linked markers in Yellow River carp against Denio rerio genome, and their functions involve in the regulation of development, cell-proliferation, energy metabolism, and so on. The identification of significant QTL and potential growth-related genes in this study provides valuable genomic resources for the study of genetic mechanism underlying growth and development, and would contribute to accelerate the progress of marker-assisted selection in Yellow River carp.

Soil-Induced Increased Fertilization and Hatching of Carps

Soil-Induced Increased Fertilization and Hatching of Carps

Effects of triclosan on hormones and reproductive axis in female Yellow River carp (Cyprinus carpio): Potential mechanisms underlying estrogen effect

Triclosan (TCS), a member of the class of compounds called pharmaceutical and personal care products (PPCPs), is a broad antibacterial and antifungal agent found in a lot of consumer products. However, TCS hormone effect mechanism in teleost female fish is not clear. Female Yellow River carp (Cyprinus carpio) were exposed to 1/20, 1/10 and 1/5 LC50 TCS (96h LC50 of TCS to carp) under semi-static conditions for 42days. Vitellogenin (Vtg), 17β-estradiol (E2), testosterone(T), estrogen receptor (Er), gonadotropin (GtH), and gonadotropin-releasing hormone (GnRH) levels were measured by enzyme-linked immunosorbent assay (ELISA). Meanwhile, we also examined the mRNA expressions of aromatase, GtHs-β, GnRH, and Er by quantitative real-time PCR (qRT-PCR). The results indicated that 1/5 LC50 TCS induced Vtg in hepatopancreas of female carps by interference with the hypothalamic–pituitary–gonadal (HPG) axis at multiple potential loci through three mechanisms: (a) TCS exposure enhanced the mRNA expression of hypothalamus and gonadal aromatase which converts androgens into estrogens, subsequently increasing serum concentrations of E2 to induce Vtg in hepatopancreas; (b) TCS treatment increased GnRH and GtH-β mRNA expression and secretion, causing the disturbance of reproductive endocrine and the increase of E2 to induce Vtg in hepatopancreas; (c) TCS exposure enhanced synthesis and secretion of Er, then it bound to Er to active Vtg synthesis. These mechanisms showed that TCS may induce Vtg production in female Yellow River carp by Er-mediated and non-Er-mediated pathways.

Transcriptome analysis of three critical periods of ovarian development in Yellow River carp (Cyprinus carpio)

Ovary development is a complex process involving numerous genes; the molecular mechanism underlying the ovary development of carp is still unknown. Here we used Illumina HiSeq™ 2500 to explore the transcriptome of undifferentiated gland (PG), juvenile ovary (OJ) and adult ovary (OA) of Yellow River carp (Cyprinus carpio). A total of 58,749 unigenes were obtained, comprising 45,707 known genes and 13,042 new genes. We identified differentially-expressed genes (DEGs) during development and characterized the functional properties of DEGs by comparison with the gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes databases. qRT-PCR was used to analyze the expression of 22 DEGs and the results corresponded with those of RNA-Seq. Among DEGs between PG and OJ, some upstream regulators of gonad development were upregulated in PG, such as cyp19a and sox9, while some oocyte-specific genes were upregulated in OJ, such as nobox, bmp15 and zp2. Among DEGs between OJ and OA, many oocyte physiological function-related genes were upregulated in OA, such as fem-1 and foxl2. GO analysis showed a higher number of DEGs from PG–OJ analysis were assigned to reproduction terms. Furthermore, our investigation has also revealed DEGs identified from PG–OJ analysis were enriched in several important functional pathways, such as Fanconi anemia and the notch signal pathway. These data suggested a dynamic shift in gene expression during ovary development, and DEGs between PG and OJ provided crucial candidate gene data for the study of ovarian differentiation. Additionally, a total of 1,776,769 single nucleotide polymorphisms and 157,279 INDEs were revealed from transcriptome data. This result will contribute to knowledge of ovary differentiation of Yellow River carp.

An effective memetic algorithm for heterogeneous vehicle CARP

An effective memetic algorithm for heterogeneous vehicle CARP

Reaffirming the Failure Causes of CARP and CARPER in the Philippines

Reaffirming the Failure Causes of CARP and CARPER in the Philippines

Identification and profiling of Cyprinus carpio microRNAs during ovary differentiation by deep sequencing

BackgroundMicroRNAs (miRNAs) are endogenous small non-coding RNAs that regulate gene expression by targeting specific mRNAs. However, the possible role of miRNAs in the ovary differentiation and development of fish is not well understood. In this study, we examined the expression profiles and differential expression of miRNAs during three key stages of ovarian development and different developmental stages in common carp Cyprinus carpio.ResultsA total of 8765 miRNAs were identified, including 2155 conserved miRNAs highly conserved among various species, 145 miRNAs registered in miRBase for common carp, and 6505 novel miRNAs identified in common carp for the first time. Comparison of miRNA expression profiles among the five libraries identified 714 co-expressed and 2382 specific expressed miRNAs. Overall, 150, 628, and 431 specifically expressed miRNAs were identified in primordial gonad, juvenile ovary, and adult ovary, respectively. MiR-6758-3p, miR-3050-5p, and miR-2985-3p were highly expressed in primordial gonad, miR-3544-5p, miR-6877-3p, and miR-9086-5p were highly expressed in juvenile ovary, and miR-154-3p, miR-5307-5p, and miR-3958-3p were highly expressed in adult ovary. Predicted target genes of specific miRNAs in primordial gonad were involved in many reproductive biology signaling pathways, including transforming growth factor-β, Wnt, oocyte meiosis, mitogen-activated protein kinase, Notch, p53, and gonadotropin-releasing hormone pathways. Target-gene prediction revealed upward trends in miRNAs targeting male-bias genes, including dmrt1, atm, gsdf, and sox9, and downward trends in miRNAs targeting female-bias genes including foxl2, smad3, and smad4. Other sex-related genes such as sf1 were also predicted to be miRNA target genes.ConclusionsThis comprehensive miRNA transcriptome analysis demonstrated differential expression profiles of miRNAs during ovary development in common carp. These results could facilitate future exploitation of the sex-regulatory roles and mechanisms of miRNAs, especially in primordial gonads, while the specifically expressed miRNAs represent candidates for studying the mechanisms of ovary determination in Yellow River carp.

Histopathological study of common carp (Cyprinus carpio) fed aflatoxin-contaminated diets

This study aimed to evaluate the effects of aflatoxin-contaminated diet on histopathological alterations of the gill, liver, kidney and intestine tissues in common carp. Fish were randomly distributed into 15 tanks, i.e. in five experimental groups; (I) control fed with normal diet without solvent and aflatoxin, (II) positive control received feed with only solvent, and (III-V) fed on diets containing 0.5, 0.7 and 1.4 mg kg -1 of aflatoxin, respectively. After 21-days, 12 fish per treatment were randomly caught, anesthetized and euthanized. Then, histological sections of the tissues were prepared. The main aflatoxicosis symptoms in the gills were fusion and disorganisation of the secondary gill lamellae, shortening of the secondary lamellae, inflammation of mucous membranes, and exfoliation of the gill epithelium. Liver of the infected fish indicated cloudy swelling of hepatocytes, cellular hypertrophy, formation of vacuoles in the cytoplasm, and necrosis of liver parenchyma. Expansion of Bowman’s space, necrosis of urinary tract, exfoliation and degeneration of the urinary tract epithelium, expansion of the urinary lumen and dilation of the urinary space were observed symptoms in the kidney. Changes in the intestine of the aflatoxin-treated fish were; expansion of goblet cells, necrosis of mucous layers, exfoliation of the mucous epithelium, and bleeding in the intestinal wall. The results indicates that feeding common carp with diets contaminated with aflatoxin, even in low concentrations (≤ 1.4 mg kg -1 feed) can cause histopathological damages and disturb their physiological balance.

Effect of Ethanolic and Aquatic Extract of Harmal ( Peganum harmala ) on the Activity of Staphylococcus aureus in Minced Meat of Silver Carp ( Hypophthalmichthys molitrix ) in Different Times of Storage at Refregerated (4°C)

In this study, the plant Peganum collected for providing its ethanolic and aquatic extract. 0.01, 0.02 and 0.35 µg/ml of it were prepared and kept at 4°C for evaluating it’s effect on growth of Staphylococcus aureus in minced meat of Silver carp in days 0, 1, 2, 5, 7, 9, 11, 13. Results showed the ethanolic extract of Peganum harmala at 0.35 µg/ml has the most anti-microbial effect and also, the aquatic extract prevented the growth of Staphylococcus aureus. Proxide value (PV) was minimum in control during 13 days. The maximum and minimum of thiobarbiutic acid (TBA) observed at 13th day in control and day zero at 0.01 µg/ml, respectively. The minimum of fat was in control in 11th and 13th days. Maximum level of fat observed at 0.35 µg/ml at the first and 13th day. Based on results adding 0.35 µg/ml of harmal in minced meat of Sliver carp is recomended.

Identification of differentially-expressed genes in early developmental ovary of Yellow River carp (Cyprinus carpio var) using Suppression Subtractive Hybridization

Ovary development appears to be under polygenic control, and is influenced by multiple genetic factors that may vary from organism to organism. To gain a better insight into the molecular mechanisms of carp ovary development, Suppression Subtractive Hybridization (SSH) DNA libraries in two species of Yellow River carp were analyzed. Primordial gonads and stage II ovaries were used as testers, and adult ovaries as drivers. One hundred and fifty differentially-expressed candidate genes were examined by Southern blot microarray hybridization. We identified 41 differentially-expressed genes in the PG (Primordial gonad) library and 37 in the stage II ovary library. Gene Ontology Biological Pathway analysis showed the genes were involved in signal transduction, proteolysis process, cell differentiation, TGF-β signal and other biological responses. Twenty-two candidate genes were selected and further characterized using qRT-PCR. Pvalb, epd, and MYH were found specifically expressed in PG, while bmp2b, desmin and fp1 were specifically expressed in stage II ovary. Our results indicate that these genes could be used as biomarkers of the early development of carp ovary. This finding will provide a basis for further understanding of the complex gonad developmental molecular mechanisms in Yellow River carp.

Dispersal patterns of endogenous bacteria among grass carp (Ctenopharyngodon idellus) guts

The formation and regulation of vertebrate endogenous intestinal microbiota has been widely studied as the microbiota plays a crucial role in the host nutrition, development, and health. Despite the importance of microbiota for host health, it is still unclear whether the endogenous intestinal microorganisms are genetically distinct or whether they are genetically related with each other in different host individuals. In the present study, the dispersal situation of the endogenous intestinal bacteria in grass carp was investigated by constructing bacterial 16S rRNA gene clone libraries. The results indicate that the bacteria harbored in the grass carp gut could be separated into the following two groups: a- the private operational taxonomic units (OTUs), which include Cetobacterium somerae, Aeromonas jandaei, Citrobacter freundii, Achromobacter xylosoxidans and Bacteroides species; b- the shared OTUs, which include Vibrio cholerae, Plesiomonas shigelloides and Pasteurella speices. The results obtained in this investigation provide valuable information for assessing the mechanism of spread of the endogenous intestinal bacteria, especially the pathogenic ones. However, the mechanisms involved in different modes of bacterial dispersal in the grass carp gut still require further research.

Short communication: Determination of total mercury in common carp, Cyprinus carpio, large scaled barb, Barbus grypus, tiger tooth croaker, Otolithes ruber and from surface waters in Khuzestan, Iran

Short communication: Determination of total mercury in common carp, Cyprinus carpio, large scaled barb, Barbus grypus, tiger tooth croaker, Otolithes ruber and from surface waters in Khuzestan, Iran

Reviewing Nutritional Quality of Small Freshwater Fish Species

Small freshwater fish species (SIFFs) constitute one of the major sources of nutritious food for human being as they provide balanced nutrition; subsistence and supplementary income to the rural population in India. The nutritive values of them depend upon their biochemical composition, such as protein, amino acids, lipid, fatty acids, carbohydrate, vitamins and minerals. This review addresses motivating interest in this attractive group of SIFFs by summarizing what little we do know about them comparing with other freshwater fish species found in India as well as different parts of the world. It is observed that SIFFs with a high content of MUFA (mono unsaturated fatty acid), PUFA (poly unsaturated fatty acid) as well as EPA (eicosapentaenoic acid) and DHA (docosahexaenoic acid); which makes them curative diet also. Until recently, possibilities of culturing them in combination with the IMC (Indian major carp) are unexplored. This study also exposed that the small and shallow water bodies may open-handedly be used for SIFFs culture and indicates the feasibility of attaining a good production of the same along with IMCs. Conservation strategy should be undertaken and taking SIFFs in every day diet may result in better and advanced protection against coronary heart disease (CHD) and other lifestyle related disease. Exploration of the nutritional eminence of them will encourage fish farmers to promote mixed culture of SIFFs in India in proper scientific way.

Common carp - still unused potential

Karpfen –vernachlässigte hochwertige Nährstoffquelle Der Karpfen gehört zu den kultiviertesten Fischarten weltweit; seine Produktion steigt kontinuierlich an. Der Süßwasserfisch stellt eine bedeutende Nahrungsquelle in den Entwicklungsländern dar; in den entwickelten Ländern wird er aber häufig für eine teuere Delikatesse gehalten. Der Fisch ist nicht nur ein hervorragendes und äußerst nahrhaftes Nahrungsmittel (Eiweiße, Lipide, Mikronährstoffe), er enthält zudem wichtige bioaktive Inhaltsstoffe mit einer wohltuenden Wirkung auf die menschliche Gesundheit; dabei spielen insbesondere die n-3 mehrfach ungesättigten Fettsäuren (PUFA) eine bedeutende Rolle bei der Vorbeugung von Herz-Gefäßkrankheiten. Trotz dem hohen Gehalt an wertvollen Nährstoffen wird der Süßwasserfisch als eine bedeutende Nährstoffquelle sehr häufig vernachlässigt. Seit einigen Jahren kommt dem Süßwasserfisch als einer Quelle von n-3 mehrfach ungesättigten Fettsäuren eine immer größere Bedeutung zu. In den letzten Jahren wurde die mögliche Schutzwirkung des Karpfens auf das Herz untersucht; dabei konnte nachgewiesen werden, dass das Karpfenfleisch zahlreiche positive Auswirkungen bei der Vorbeugung von Herz-Gefäßkrankheiten hat und es als gesunde Nahrung anerkannt und gefördert werden sollte. Um Karpfenprodukte mit bestmöglicher Qualität liefern zu können, bedarf es zahlreicher Untersuchungen und Innovationen zur Verbesserung der kompletten Produktionskette vom Fischteich bis zum Teller.

Growth and Skin Color of Red- and White-colored Fancy Carp Cyprinus carpio var. koi Reared at Different Water Temperatures

Growth and Skin Color of Red- and White-colored Fancy Carp Cyprinus carpio var. koi Reared at Different Water Temperatures

АНАЛІЗ ГЕНЕТИЧНОЇ СТРУКТУРИ ОКРЕМИХ ТИПІВ УКРАЇНСЬКОГО ЛУСКАТОГО КОРОПА

АНАЛІЗ ГЕНЕТИЧНОЇ СТРУКТУРИ ОКРЕМИХ ТИПІВ УКРАЇНСЬКОГО ЛУСКАТОГО КОРОПА

Painting of a carp jumping & painting of a carp changing into a dragon

Painting of a carp jumping & painting of a carp changing into a dragon