Genetic variation between hybrid (Labeo rohita ♂, Cirrhinus mrigala ♀ and Labeo rohita) by RAPD marker / Variação genética entre híbridos (Labeo rohita ♂, Cirrhinus mrigala ♀ e Labeo rohita) a partir do marcador RAPD

The present work was to study the genetic variability between the major carps Labeo rohita and Cirrhinus mrigala and their hybrids of L. rohita (male♂) and C. mrigala (female♀). Genetic variability was studied by employing RAPD molecular markers. 25 samples of each target species having different sizes with the same age group for the determination of interspecific variation were collected. The morphometric parameters such as body weight, total length, tail length, and lengths of dorsal and anal fins of each individual were recorded and results showed that wet body weight, total length, dorsal fin, anal fin, and tail fin length are positively correlated and then the DNA was extracted using the inorganic salt-based method and conformed by Gel electrophoresis. Twenty-four arbitrary decamer primers were used to get species-specific RAPD analysis Distinct and highly reproducible RAPD profiles with significant genetic variability was detected among species. Only five primers showed amplification. The RAPAD primer OPB-05 produced a total of seven bands out of these 5 monomorphic and 2 polymorphic, so in this case, the percentage polymorphism was 28.57%. The Hybrid show more than a 50% difference from the Labeo rohita. This shows that the Hybrid more resembles C.mrigala. Phylogenetic analysis demonstrated that hybrid (L. rohita ♂ X Cirrhinus mrigala ♀) is the closest to C. mrigala and the farthest from L. rohita. Overall data are presented concerning the applications of RAPD markers for hybrid identification, genetic diversity assessment, and studying taxonomic relationships at a molecular level.

O presente trabalho teve como objetivo estudar a variabilidade genética entre as carpas maiores Labeo rohita e Cirrhinus mrigala e seus híbridos de L. rohita (machos) e C. mrigala (fêmeas). A variabilidade genética foi estudada empregando marcadores moleculares RAPD. 25 amostras de cada espécie-alvo com tamanhos diferentes e com a mesma faixa etária foram coletadas para a determinação da variação interespecífica. Os parâmetros morfométricos como peso corporal, comprimento total, comprimento da cauda e comprimento das nadadeiras dorsal e anal de cada indivíduo foram registrados. O DNA foi extraído através do método à base de sal inorgânico e conformado por eletroforese em gel. 24 primers decâmeros arbitrários foram usados ​​para obter a análise RAPD espécie-específica. Perfis RAPD distintos e altamente reprodutíveis com significativa variabilidade genética foram detectados entre as espécies. Apenas 5 primers apresentaram amplificação. O primer RAPAD OPB-05 produziu um total de 7 bandas, dessas, 5 monomórficas e 2 polimórficas, portanto, neste caso, o percentual de polimorfismo foi de 28,57%. O Hybrid mostrou mais de 50% de diferença do Labeo rohita. Isso mostra que o híbrido se parece mais com o C.mrigala. A análise filogenética demonstrou que o híbrido (L. rohita macho X Cirrhinus mrigala fêmea) é o mais próximo de C. mrigala e o mais distante de L. rohita. Foram apresentados dados relativos à aplicação de marcadores RAPD para identificação de híbridos, avaliação de diversidade genética e estudo de relações taxonômicas ao nível molecular.

Molecular characterization and expression analysis of anti-Müllerian hormone in common carp (Cyprinus carpio) adult testes.

Anti-Müllerian hormone (Amh) is a member of the transforming growth factor-ß (Tgf-ß) superfamily required in the regression of Müllerian ducts during gonadal sex differentiation of higher vertebrates. Teleost fish lack Müllerian ducts, but identified Amh orthologs have been shown to exert crucial functions during sex determination and differentiation of several species of teleosts. However, the function of Amh during gametogenesis in adult fish remains poorly investigated. Therefore, to expand present knowledge on the role of Amh in teleosts, the present study aimed to isolate and clone full-length amh cDNA in the common carp, Cyprinus carpio, and examine its expression levels throughout the male reproductive cycle and in response to different hormone treatments of testicular explants. Molecular cloning and characterization showed that the common carp Amh precursor amino acid sequence shared common features to other fish Amh precursors, including a conserved C-terminus (Tgf-ß domain) and a double proteolytic cleavage site (R-X-X-R-X-X-R) upstream to the Tgf-ß domain. Expression analysis showed amh dimorphic expression in the adult gonads with higher expression in the testes than ovaries. In testes, amh mRNA was detected in Sertoli cells contacting different types of germ cells, although the expression was greatest in Sertoli cells associated with type A undifferentiated spermatogonia. Expression analysis during the reproductive cycle showed that amh transcripts were down-regulated during the developing phase, which is characterized by an increased proliferation of type A undifferentiated spermatogonia and Sertoli cells and appearance of spermatocytes (meiosis) in the testes. Furthermore, ex vivo experiments showed that a 7 day exposure to Fsh or estrogens was required to decrease amh mRNA levels in common carp testicular explants. In summary, this study provided information on the molecular characterization and transcript abundance of amh in common carp adult testes. Altogether, these data will be useful for further investigations on sex determination and differentiation in this species, and also to improved strategies for improved carp aquaculture, such as inhibiting precocious maturation of males.

Geno-cytotoxicity and congenital malformations produced by relevant environmental concentrations of aluminum, diclofenac and their mixture on Cyprinus carpio. An interactions study.

Several studies highlight the presence of aluminum and diclofenac in water bodies around the world and their ability to induce oxidative stress and a negative effect on biomolecules in several aquatic species. However, studies evaluating the toxic effect of mixtures of these contaminants are scarce. The objective of this work was to determine the genotoxic, cytotoxic and embryotoxic effect of the mixture of aluminum and diclofenac at environmentally relevant concentrations on Cyprinus carpio. Juveniles of Cyprinus carpio were exposed to 0.31 µg L-1 of diclofenac, 24.45 mg L-1 of aluminum, and a mixture of both contaminants at the same concentrations for 12, 24, 48, 72 and 96 h. After the exposure time the liver, gills and blood were extracted and the following biomarkers were evaluated: micronucleus frequency, comet assay, caspase activity and TUNEL test. On the other hand, Cyprinus carpio embryos were exposed to diclofenac (0.31 µg L-1), aluminum (0.06 mg L-1) and their mixture at the same concentrations and exposure time. Microscopic observation was performed to evaluate embryonic development at 12, 24, 48, 72 and 96 h. Diclofenac (0.31 µg L-1) induces significant increases in micronucleus frequency with respect to control (p < 0.05), in all tissues. Aluminum (24.45 mg L-1) significantly increases DNA damage index in liver and blood cells with respect to control (p < 0.05). All treatments increase caspases activity in all tissues with respect to control (p < 0.05). Diclofenac increases the percentage of TUNEL-positive cells in liver and blood; while aluminum and the mixture increases it significantly in gills and blood with respect to the control (p < 0.05). The mixture significantly delays embryonic development, while aluminum and the mixture significantly increase teratogenic index with respect to control (p < 0.05). In conclusion, exposure to environmental concentrations of aluminium, diclofenac and their mixture induces genotoxic damage, cell death by apoptosis and negative effects on the development of Cyprinus carpio and the toxic response is modified by the interaction of the xenobiotics.

Tissue distribution and early developmental expression patterns of aldolase A, B, and C in grass carp Ctenopharyngodon idellus.

Aldolase is a key enzyme involved in glycolysis, gluconeogenesis, and the pentose phosphate pathway. To establish the expression patterns of all three aldolase isozyme genes in different tissues and during early embryogenesis in lower vertebrates, as well as to explore the functional differences between these three isozymes, the grass carp was selected as a model owing to its relatively high glucose-metabolizing capability. Based on the cDNA sequences of the aldolase A, B, and C genes, the expression patterns of these three isozymes were analyzed in different tissues and during early embryogenesis using quantitative real-time polymerase chain reaction (qRT-PCR). Sequence analysis of cDNAs indicated that aldolase A, B, and C (GenBank accession numbers: KM192250, KM192251, and KM192252) consist of 364, 364, and 363 amino acids, respectively. The qRT-PCR results showed that the expression levels of aldolase A, B, and C were highest in the muscle, liver, and brain, respectively. Aldolase A and C exhibited similar expression patterns during embryogenesis, with high levels observed in unfertilized and fertilized eggs and at the blastocyst stage, followed by a decline and then increase after organogenesis. In contrast, aldolase B transcript was not detected during the unfertilized egg stage, and appeared only from gastrulation; the expression increased markedly during the feeding period (72 h after hatching), at which point the level was higher than those of aldolase A and C. These data suggest that the glucose content of grass carp starter feed should be adjusted according to the metabolic activity of aldolase B.

Association study between single nucleotide polymorphisms in leptin and growth traits in Cyprinus carpio var. Jian.

Leptin is a hormone that affects the regulation of body weight, energy expenditure, fat metabolism, food intake, and appetite. In this study, we cloned the jlLEP-A1 and jlLEP-A2 genes in Jian carp (Cyprinus carpio var. Jian) and performed an association analysis between identified polymorphisms and growth traits. Three polymorphisms in exons of jlLEP-A1 (A1-T113C) and jlLEP-A2 (A2-G415A and A2-G427A) were identified, and genotyped by the polymerase chain reaction - restriction fragment length polymorphism method in 263 female and 294 male Jian carp. All three SNPs were missense mutations. Association analysis revealed that the three SNPs were significantly associated with growth traits in male Jian carp. Only SNP A1-T113C was significantly associated with growth traits in female Jian carp. Analysis of diplotypes derived from jlLEP-A2 SNPs revealed an association with growth traits in male but not female Jian carp. These results demonstrate that polymorphisms in the leptin gene are associated with growth traits and may be used for marker-assisted selection programs in Jian carp breeding and production.

Characterization of grass carp spleen transcriptome during GCRV infection.

The aim of the study was to investigate the grass carp hemorrhagic infection pathway and its key-related genes. Grass carp reovirus (GCRV) might cause hemorrhagic disease in grass carps. Healthy grass carp fingerlings (N = 60) were divided into control and infected groups. Fish in the control group were intraperitoneally (ip) injected with 0.6% fish physiological saline; the infected group received 5,000,000 50% tissue culture infective doses of GCRV 873 standard strain, a double-stranded RNA (dsRNA) virus strain, ip, in 0.5 mL. Illumina HiSeqTM 2000 was used for transcriptome sequencing, and real-time polymerase chain reaction (PCR) used to detect complement factors II (C2), III (C3), and V (C5); profibrinolysin (PLG); and coagulation factor II (F2) expression. A total of 2,722,223 reads were detected in the control group, and 2,751,111 in the infected group. Among 11,023 unigenes obtained after transcriptome assembly, 10,021 unigenes were significantly differentially expressed. Gene ontology and KEGG analysis, a collection of databases dealing with genomes and biological pathways, were performed to classify unigenes into functional categories, to understand gene function and identify regulatory pathways. Real-time PCR analysis showed that C2, C3, C5, PLG, and F2 expression levels were down-regulated, confirming results of pathway-enrichment analysis. This is the first application of high-throughput sequencing technology to investigate the in vivo effects of GCRV, on genes and pathways involved in the immune response to infection in grass carp.

A 425 T>C polymorphism in complement C7 association with resistance to Aeromonas hydrophila in grass carp.

Aeromonas hydrophila, a widespread bacterium in the aquatic environment, causes hemorrhagic septicemia in fish. In the last decade, the disease has caused mass mortalities and tremendous economic loss in cultured fish. The complement component C7 is a terminal component of complement that interacts in a sequence of polymerization reactions with other terminal complement components to form a membrane attack complex. The formation of the membrane attack complex creates a pore in the membranes of certain pathogen that can lead to their death. The objective of this study was to identify single nucleotide polymorphisms (SNPs) in the C7 gene and to assess their association with A. hydrophila resistance in grass carp. A resource population consisting of 186 susceptible and 191 resistant grass carp was constructed. We sequenced a total of 7826 bp of the C7 gene and identified 6 SNPs that were genotyped in the resource population. The SNP -1575 A>C was positioned in the promoter region of the gene. The SNP 425 C>T identified in the coding exon was a synonymous substitution in the fourth exon. Statistical analysis showed that SNP 425 C>T was associated with the incidence of hemorrhagic septicemia. The SNPs -1575 A>C, -688 T>C, and -266 A>C were highly linked together (r(2) > 0.85). No haplotypes generated with these 3 SNPs were associated with resistance to A. hydrophila in grass carp. These findings suggest that the 425 C>T polymorphism in C7 gene may be a significant molecular marker for resistance to A. hydrophila in grass carp.

Large-scale tissue-specific and temporal gene expression profiles in Pengze crucian carp.

In the present study, the tissue-specific and temporal gene expression profiles of four catalogues of gonadal development-related genes (sex differentiation-related, steroid receptor, steroidogenic, and structural genes) were detected in nine tissues and during 11 successive developmental stages in the Pengze crucian carp (Pcc) (a triploid mono-female gynogenic fish). The results showed that these target genes exhibited overlapping distributions in various tissues, with the exception of Pcc-vasa and Pcc-cyp17a1. Gene expression profiling of the developmental stages showed that all of the target genes simultaneously reached peak expression levels at 40 and 48 days post hatching (dph). Both 40 and 48 dph appeared to be two key time points associated with the process of Pcc gonadal development. These data will provide a clear understanding of gene expression patterns associated with the gonadal development-related genes of this gynogenic teleost.

Cloning, characterization and expression analysis of coagulation factor II gene in grass carp (Ctenopharyngodon idella).

Here, we characterized the structure and function of the coagulation factor II (FII) gene in grass carp and determined its role in coagulation mechanisms. The FII gene EST was obtained using a constructed splenic transcriptome database; the full-length FII gene sequence was obtained by 3' and 5' RACE. The open reading frame (ORF) of FII was cloned and the full-length gene was found to be 1718 bp, with an ORF of 1572 bp; the gene contained a 25 bp 5'-untranslated region (UTR) and 108 bp 3'-UTR. The ORF encoded 524 amino acids, including 74 alkaline amino acids (arginine and lysine) and 69 acidic amino acids (aspartic acid and glutamic acid). The theoretical pI was 6.22. The calculated instability index (II) was 39.81, indicating that FII was a stable protein; the half-life period was predicted to be approximately 30 h. Amino acid sequence comparisons indicated that grass carp FII showed most similarity (71%) to FII of Takifugu rubripes, followed by Oplegnathus fasciatus (48% similarity) and Larimichthys crocea (47% similarity). A real-time reverse transcription PCR analysis showed that under normal circumstances, FII was most highly expressed in the liver, followed by the gill, spleen, thymus, and head-kidney (P < 0.001). After injection of the grass carp reovirus 873 (GCRV873), the pattern of FII expression was significantly altered (P < 0.001); gene expression was high after injection, suggesting a response involving the initiation of the coagulation system and defense of the body in combination with the platelet and complement system.

Single nucleotide polymorphisms of Δ6-desaturase and Elovl5 segments and their associations with common carp (Cyprinus carpio) growth traits.

Highly unsaturated fatty acids (HUFAs) are crucial for the nutritional health, physiology, and reproduction of vertebrates. The Δ6-desaturase and Elovl5 elongase genes produce essential enzymes in the biosynthetic pathway of HUFAs. Single nucleotide polymorphism (SNP) analysis of genes functionally related to the growth traits of the common carp (Cyprinus carpio var. Jian) can provide useful information for common carp molecular breeding. In this study, we isolated two Δ6 Fad genes and two Elovl5 genes from the common carp. Polymerase chain reaction-restriction fragment length polymorphism was performed, and the genotypes of three SNPs (Δ6Fad-a intron 10_C73T, Δ6Fad-b intron 10_A56G, and Elovl5-a intron 5_C64A) in 712 individuals (383 females and 329 males) were detected. Correlation analysis between the genotypes and weight gain revealed that intron 10_C73T of Δ6Fad-a, intron 10_A56G of Δ6Fad-b, and intron 5_ C64A of Elovl5-a were significantly associated with common carp weight gain. Weight gain increased with the enrichment of molecular SNP markers, consistent with the characteristics of quantitative traits. Our results indicate that Δ6Fad and Elovl5 elongase genes could be candidate genes for the molecular breeding of the common carp. This study provides useful information for the improvement of this species.

Characterization and expression of the calpastatin gene in Cyprinus carpio.

Calpastatin, an important protein used to regulate meat quality traits in animals, is encoded by the CAST gene. The aim of the present study was to clone the cDNA sequence of the CAST gene and detect the expression of CAST in the tissues of Cyprinus carpio. The cDNA of the C. carpio CAST gene, amplified using rapid amplification of cDNA ends PCR, is 2834 bp in length (accession No. JX275386), contains a 2634-bp open reading frame, and encodes a protein with 877 amino acid residues. The amino acid sequence of the C. carpio CAST gene was 88, 80, and 59% identical to the sequences observed in grass carp, zebrafish, and other fish, respectively. The C. carpio CAST was observed to contain four conserved domains with 54 serine phosphorylation loci, 28 threonine phosphorylation loci, 1 tyrosine phosphorylation loci, and 6 specific protein kinase C phosphorylation loci. The CAST gene showed widespread expression in different tissues of C. carpio. Surprisingly, the relative expression of the CAST transcript in the muscle and heart tissues of C. carpio was significantly higher than in other tissues (P < 0.01).

Genetic analysis of QTL for eye cross and eye diameter in common carp (Cyprinus carpio L.) using microsatellites and SNPs.

A group of 107 F1 hybrid common carp was used to construct a linkage map using JoinMap 4.0. A total of 4877 microsatellite and single nucleotide polymorphism (SNP) markers isolated from a genomic library (978 microsatellite and 3899 SNP markers) were assigned to construct the genetic map, which comprised 50 linkage groups. The total length of the linkage map for the common carp was 4775.90 cM with an average distance between markers of 0.98 cM. Ten quantitative trait loci (QTL) were associated with eye diameter, corresponding to 10.5-57.2% of the total phenotypic variation. Twenty QTL were related to eye cross, contributing to 10.8-36.9% of the total phenotypic variation. Two QTL for eye diameter and four QTL for eye cross each accounted for more than 20% of the total phenotypic variation and were considered to be major QTL. One growth factor related to eye diameter was observed on LG10 of the common carp genome, and three growth factors related to eye cross were observed on LG10, LG35, and LG44 of the common carp genome. The significant positive relationship of eye cross and eye diameter with other commercial traits suggests that eye diameter and eye cross can be used to assist in indirect selection for many commercial traits, particularly body weight. Thus, the growth factor for eye cross may also contribute to the growth of body weight, implying that aggregate breeding could have multiple effects. These findings provide information for future genetic studies and breeding of common carp.

Body color development and genetic analysis of hybrid transparent crucian carp (Carassius auratus).

The aim of this study was to investigate the genetic mechanism of the transparent trait in transparent crucian carp. We observed body color development in transparent crucian carp larvae and analyzed heredity of color in hybrids produced with red crucian carp, ornamental carp, and red purse carp. The results showed that the body color of the newly hatched larvae matured into the adult pattern at approximately 54 days post-hatching. Two inter-species reciprocal crosses between transparent crucian carp and red crucian carp, and self-cross F1 of transparent crucian carp and self-cross F1 of red marking transparent crucian carp were conducted, and results indicated that the transparent-scaled trait is dominant over the normal-scaled trait. Furthermore, the transparent trait is a quantitative trait. All offspring in the four inter-genera reciprocal crosses of transparent crucian carp with ornamental carp and red purse carp were hybrids of common carp and crucian carp, and had a relatively low survival rate of 10-20%. Moreover, the transparent-scaled trait was observed to be dominant over the normal-scaled trait in the hybrid fish. In conclusion, our results suggest that the genetic mechanism underlying the color of goldfish is complex and requires further investigation.

Involvement of the mitfa gene in the development of pigment cell in Japanese ornamental (Koi) carp (Cyprinus carpio L.).

A colored phenotype is an important feature of ornamental fish. In mammals, microphthalmia-associated transcription factor (MITF) was found to regulate the development of melanocytes. In this study, the mitfa cDNA was first cloned from the Japanese ornamental (Koi) carp (Cyprinus carpio L.), an important ornamental freshwater fish. The full-length cDNA of the mitfa gene contains 1634 bp, coding for 412 amino acids in Koi. The identity degree of mitfa amino acid sequences between the Koi carp and zebrafish is 92.9%. We tested the expression of the mitfa gene in several varieties of Koi using reverse transcription-polymerase chain reaction and found that the mitfa gene is highly expressed in the skin tissues of the Taisho sanke and the Procypris merus. Interestingly, the mitfa gene was also expressed in the Kohaku and Yamabaki ogon, although melanocytes were not observed in the skin. Koi carp embryos were transparent and colorless, while after hatching, different types of pigment cells successively emerged in a fixed order. In Taisho sanke, melanocytes first appeared in the trunk at approximately 12 days of age. Subsequently, there was a large area of melanocytes by 30 days of age. The expression level of the mitfa mRNA was low in early embryos and newly hatched larvae, and increased to high levels in 30-day-old fry. The results show that the mitfa gene is involved in regulating fish body color in the development of both melanocytes and pigment cells.

Polymorphism analysis of the intron one of insulin-like growth factor 2 receptor gene (IGF2R) in FFRC strain common carp (Cyprinus carpio L.) and its relationship with growth performance.

The insulin-like growth factor 2 receptor gene (IGF2R) encodes a transmembrane protein receptor and acts to sequester and degrade excess circulating insulin-like growth factor 2, which is critical for normal mammalian growth and development. Thus, IGF2R may serve as a candidate gene underlying growth trait in the common carp. In this study, we isolated the intron one of common carp IGF2R and detected the diversity in 3 continuous generations of FFRC strain common carp. A total of 8 loci were detected within this region, which were named in accordance with their location (i.e., Loc84, Loc106, Loc119, Loc130, Loc145, Loc163, Loc167, and Loc265). Loc106, Loc119, and Loc145 were moderately polymorphic; while Loc84, Loc130, Loc163, Loc167, and Loc265 exhibited slight level of polymorphism. However, significant differences between polymorphism information content values were not observed among the different generations. For Loc145, all generations deviated from Hardy-Weinberg equilibrium. The total number of significant linkage disequilibria for all generations equaled 40. Among them, 4 pairs were detected in each population, while 8 pairs were found in the 2nd and 3rd generations. For Loc130, the G/T genotype exhibited higher body weight when compared to that of the G/G genotype. The frequency of the homozygous G/G genotype reached 87.96%; thus, we can improve FFRC strain common carp growth performance by increasing the percentage of the G/T genotype within a breeding population. Therefore, the G/T genotype could be used as a molecular marker for superior growth traits.

Transcriptome analysis of the grass carp (Ctenopharyngodon idella) using 454 pyrosequencing methodology for gene and marker discovery.

Total RNA isolated from the brain, muscle, liver, gonad, and intestinal tissues of grass carp was pooled to construct cDNA libraries. Using 454 pyrosequencing, a total of 738,604 high-quality reads were generated from the normalized cDNAs of the pooled individuals. Clustering and assembly of these reads produced a set of 37,086 all-unigene sequences after BLAST. Of these, 24,010 (64.74%) were annotated in the National Center for Biotechnology Information database, and 3715 simple sequence repeats and 2008 single nucleotide polymorphisms were identified in this EST dataset as potential molecular markers. This study provides new data for functional genomic and biological research on grass carp. The markers identified in this study will enrich the currently used molecular markers and facilitate marker-assisted selection in grass carp-breeding programs. These results also demonstrate that transcriptomic analysis based on 454 sequencing is a powerful tool for gene discovery and molecular marker development in non-model species.

Efficiency of DNA extraction from different carp tissue using the sodium chloride (NaCl) protocol / Eficiência na extração de DNA de diferentes tecidos de carpas através do protocolo de cloreto de sódio (NaCl)

With advances of farming and research in the area of molecular genetics, studies that can help with obtaining good quality DNA are necessary. The objective was to evaluate the efficiency of DNA extraction in different types of tissues of three species of carp by using the protocol of DNA extraction with Sodium Chloride (NaCl). The samples were subjected to DNA extraction, and the integrity was visualized on 1.5% agarose gel. In a total of 72 samples used for DNA extraction, all of them were positive, confirmed by the presence of bands on agarose gel. The capacity of amplifying the extracted DNA was tested by amplification reactions using the RAPD (random amplification of polymorphic DNA) technique, confirming that the DNA was of good quality for use in subsequent studies with molecular markers.(AU)

Com o avanço da piscicultura e das pesquisas na área da genética molecular, existe a necessidade de estudos que possam aperfeiçoar a obtenção de DNA com boa qualidade. Diante disso, o objetivo desse trabalho foi avaliar a eficiência da extração de DNA em diferentes tipos de tecidos de três espécies de carpas, através do protocolo de extração de DNA com cloreto de sódio (NaCl). As amostras foram submetidas à extração de DNA e a integridade foi visualizada em gel de agarose 1,5%. Em um total de 72 amostras utilizadas na extração de DNA, todas foram positivas, confirmadas com a presença de banda no gel de agarose. A capacidade de amplificação do DNA extraído foi testada através de reações de amplificação utilizando a técnica RAPD (polimorfismos de DNA amplificados ao acaso), confirmando que o DNA apresenta boas condições para utilização em estudos posteriores com marcadores moleculares.(AU)

Efficiency of DNA extraction from different carp tissue using the sodium chloride (NaCl) protocol / Eficiência na extração de DNA de diferentes tecidos de carpas através do protocolo de cloreto de sódio (NaCl)

With advances of farming and research in the area of molecular genetics, studies that can help with obtaining good quality DNA are necessary. The objective was to evaluate the efficiency of DNA extraction in different types of tissues of three species of carp by using the protocol of DNA extraction with Sodium Chloride (NaCl). The samples were subjected to DNA extraction, and the integrity was visualized on 1.5% agarose gel. In a total of 72 samples used for DNA extraction, all of them were positive, confirmed by the presence of bands on agarose gel. The capacity of amplifying the extracted DNA was tested by amplification reactions using the RAPD (random amplification of polymorphic DNA) technique, confirming that the DNA was of good quality for use in subsequent studies with molecular markers.

Com o avanço da piscicultura e das pesquisas na área da genética molecular, existe a necessidade de estudos que possam aperfeiçoar a obtenção de DNA com boa qualidade. Diante disso, o objetivo desse trabalho foi avaliar a eficiência da extração de DNA em diferentes tipos de tecidos de três espécies de carpas, através do protocolo de extração de DNA com cloreto de sódio (NaCl). As amostras foram submetidas à extração de DNA e a integridade foi visualizada em gel de agarose 1,5%. Em um total de 72 amostras utilizadas na extração de DNA, todas foram positivas, confirmadas com a presença de banda no gel de agarose. A capacidade de amplificação do DNA extraído foi testada através de reações de amplificação utilizando a técnica RAPD (polimorfismos de DNA amplificados ao acaso), confirmando que o DNA apresenta boas condições para utilização em estudos posteriores com marcadores moleculares.

Molecular characterization, expression, and immunological response analysis of the TWEAK and APRIL genes in grass carp, Ctenopharyngodon idella.

TWEAK and APRIL are important members of the TNF superfamily, which play a crucial role in several diseases. Here, we describe the identification of grass carp (Ctenopharyngodon idella) homologs of TWEAK and APRIL (designated gcTWEAK and gcAPRIL, respectively) and their response to Aeromonas hydrophila and Aquareovirus infection. The gcTWEAK cDNA sequence contains 2273 bases with an open reading frame of 753 bases encoding 250-amino acid residues. The gcTWEAK protein contains a predicted transmembrane domain, a putative furin protease cleavage site, 3 conserved cysteine residues, and a typical TNF homology domain. The gcAPRIL cDNA sequence contains 1408 bases with an open reading frame of 747 bases encoding 248-amino acid residues. The gcAPRIL protein contains a predicted transmembrane domain, a putative furin protease cleavage site, 2 conserved cysteine residues, and a typical TNF homology domain corresponding to other, known APRIL homologs. Reverse transcription-polymerase chain reaction analysis shows that both gcTWEAK and gcAPRIL transcripts are predominantly expressed in the skin, spleen, and head kidney, and they are significantly upregulated in most immune tissues by A. hydrophila and Aquareovirus infections. Our results demonstrate that liver is the most responsive tissue against bacterial infection, whereas gill is the most responsive tissue against viral infection. The association of increased gcTWEAK and gcAPRIL expression after bacterial and viral infections suggests that they play a potentially important role in the immune system of fish.

Complete mitochondrial genome of a natural triploid crucian carp mutant, Carassius auratus var. pingxiangnensis, and phylogenetic analysis of different ploidies in crucian carp.

Carassius auratus var. pingxiangnensis is a natural triploid crucian carp mutant. In order to understand its placement and genetic background at the gene level, the characteristics of mitochondrial DNA sequences and phylogenetic relationship were examined. The results showed that the mitochondrial DNA is a circular double-stranded DNA molecule that is 16,576 bp in length with 13 protein-coding genes, 22 transfer RNA genes, 2 ribosomal RNA genes, and a non-coding control region. Mitochondrial genes overlapped by a total of 40 bp in 11 different locations from 1 to 14 bp. The base composition of the C. auratus mitogenome was estimated to be 29.70% A, 26.74% C, 15.35% G, and 28.21% T. The central conserved blocks and the conserved blocks were compared and were similar among C. auratus var. pingxiangnensis and six other cyprinids with different ploidies. The origin of light strand replication was similar to that of other vertebrates; it was 33 bp, but the characteristic sequence motif 5ꞌ-GCCGG-3ꞌ at the base of the stem within tRNA(Cys) was mutated to 5ꞌ-GGCGG- 3ꞌ. Our phylogenetic analysis based on whole mitogenome sequences indicated that C. auratus var. pingxiangnensis was clustered with C. auratus and then sister-grouped with Carassius gibelio. The systemic developmental tree of crucian carp with different chromosome ploidies showed that diploid C. auratus auratus was clustered with triploid C. auratus auratus, sister-grouped with tetraploid C. auratus auratus, and clustered with other diploid, triploid, and tetraploid C. auratus.