RESUMO
BACKGROUND: Brachyura crab is the largest branch of Decapoda crustacean. Phylogenetic relationships within Brachyura remain controversial to be investigated. The mitochondrial genome (mitogenome) is an important molecular marker for studying the phylogenetic relationships of Brachyura. METHODS AND RESULTS: To understand the phylogeny of Brachyura, the three complete mitogenomes from Charybdis annulata, Leptodius exaratus, and Spider crab were sequenced and annotated. Their full length was 15,747, 15,716, and 16,608 bp long, respectively. The first two crabs both contained 13 protein-coding genes (PCGs), two rRNA genes, 22 tRNA genes and a control region. However, Spider crab contained 13 PCGs, two rRNA genes, 25 tRNA genes and a control region. The mitogenomes of each of the three crabs exhibited high AT content (67.8%, 69.1%, and 70.8%), with negative AT skews (-0.014, - 0.028, and - 0.017) and GC skews (-0.269, - 0.286, and - 0.341). The gene order of C. annulata was identical to the ancestor of Brachyura. Compared with the ancestor of Brachyura, L. exaratus exhibited the gene rearrangements of Val (V)-rrnS-control region, and Spider crab had the four copies of Lys (K). Phylogenetic analyses indicated that C. annulata belonged to Portunidae family, Portunoidea superfamilies, L. exaratus belonged to Xanthidae family, Xanthoidea superfamilies, and Spider crab belonged to Mithracidae family, Majoidea superfamilies. Phylogenetic analyses showed that the two species (Somanniathelphusa boyangensis and Huananpotamon lichuanense) belonging to the Potamoidea were sister groups to the Thoracotremata, thus supporting the conclusion that Heterotremata is polyphyletic. CONCLUSION: The results of this study enriched the crab mitogenome database and enabled us to better understand the phylogenetic relationships of Brachyura.
Assuntos
Braquiúros , Genoma Mitocondrial , Animais , Filogenia , Genoma Mitocondrial/genética , Braquiúros/genética , Rearranjo Gênico/genética , RNA de Transferência/genéticaRESUMO
Sesarmops sinensis is a dominant omnivorous crab species, which plays an important ecological function in salt marsh ecosystems. To better understand its immune system and immune related genes under pathogen infection, the transcriptome was analyzed by comparing the data of S. sinensis hepatopancreas stimulated by PBS and PGN. A set of assembly and annotation identified 39,039 unigenes with an average length of 1105 bp, obtaining 1300 differentially expressed genes (DEGs) in all, which included 466 remarkably up-regulated unigenes and 834 remarkably down-regulated unigenes. In addition, based on mensurable real time-polymerase chain reaction and high-throughput sequencing, several immune responsive genes were found to be markedly up-regulated under PGN stimulation. In conclusion, in addition to enriching the existing transcriptome data of S. sinensis, this study also clarified the immune response of S. sinensis to PGN stimulation, which will help us to further understand the crustacean's immune system.
Assuntos
Braquiúros , Hepatopâncreas , Animais , Braquiúros/genética , Ecossistema , Perfilação da Expressão Gênica , Peptidoglicano/genética , TranscriptomaRESUMO
This study isolated CFI gene from Pelteobagrus fulvidraco and named it PfCFI. The cDNA of PfCFI is 2374â¯bp long, including a 52â¯bp 5' untranslated sequence, a 222â¯bp 3' untranslated sequence, and an open reading frame (ORF) of 2100â¯bp encoding polypeptide consisting of 699 amino acids. Phylogenetic analysis revealed that the PfCFI was closely related to CFI of Ictalurus punctatus. Real-time quantitative reverse transcription-PCR (qRT-PCR) analysis indicate that there is the PfCFI gene which expressed in all the rest of tested tissues in varied levels, and mainly distributed in liver and least in heart. The reseachers induce the expressions level of PfCFI gene in liver, spleen, head kidney and blood at different points in time after challenged with lipopolysaccharide (LPS), and polyriboinosinic polyribocytidylic acid (poly I:C), respectively. Together these results suggested that CFI gene plays an important role in resistance to pathogens in yellow catfish immunity.
Assuntos
Peixes-Gato/genética , Fator I do Complemento/genética , Proteínas de Peixes/genética , Imunidade Inata , Animais , Peixes-Gato/imunologia , Fator I do Complemento/metabolismo , Proteínas de Peixes/metabolismo , Rim/metabolismo , Lipopolissacarídeos/toxicidade , Fígado/metabolismo , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Baço/metabolismoRESUMO
As an important economic species in China, aquaculture of the crayfish Procambarus clarkii has suffered huge losses due to infection by pathogenic bacteria, mainly by Aeromonas hydrophila, which leads to high mortality and huge economic loss. To better understand the immune response of crayfish against bacterial infection, we compared and analyzed transcriptome data of hepatopancreatic tissue from P. clarkii that were either challenged with A. hydrophila or treated with PBS. After assembly and annotation of the data, 32,041 unigenes with an average length of 1512 base pairs were identified. Compared to control group, Differential gene expression (DEG) analysis revealed 608 DEGs were obtained, of which 274 unigenes were upregulated and 334 were downregulated in the A. hydrophila group. Furthermore, the expression levels of eight selected immune-related DEGs were validated by qRT-PCR, substantiating the reliability of RNA-seq results. This study not only provides effective data support for immune defense strategies of P. clarkii in response to bacterial infections, but also provides new information about the P. clarkii immune system and defense mechanisms, and a valuable basis for further studies to elucidate the molecular immune mechanisms of this species.
Assuntos
Aeromonas hydrophila , Astacoidea , Animais , Astacoidea/genética , Perfilação da Expressão Gênica , Reprodutibilidade dos Testes , TranscriptomaRESUMO
Chromium (Cr) as a chromate anion has a strong redox capacity that seriously threatens the ecological environment and human health. Cr can contaminate water and impart toxicity to aquatic species. Procambarus clarkii is an important food source that once represented a large proportion of the aquaculture industry due to its rapid reproduction and high economic value. However, there have been reports on the death of P. clarkii due to heavy metal pollution. The underlying mechanism regarding heavy metal toxicity was studied in this paper. The transcriptome data of hemocytes extracted from P. clarkii injected with Cr were analyzed by high-throughput sequencing and compared to the control group. In total, 48,128,748 clean reads were obtained in the treatment group and 56,480,556 clean reads were obtained in the control group. The reads were assembled using Trinity and the identified unigenes were then annotated. Then, 421 differentially-expressed genes (DEGs) were found, 170 of which were upregulated and 251 downregulated. Many of these genes were found to be related to glutathione metabolism and transportation. The glutathione metabolic pathway of P. clarkii was thus activated by Cr exposure to detoxify and maintain body function. Validation of DEGs with quantitative real-time PCR confirms the changes in gene expression. Thus, this study provides data supporting a glutathione-focused response of P. clarkii to exposure to heavy metals.
Assuntos
Astacoidea , Clarkia , Animais , Antioxidantes , Astacoidea/genética , Cromo/toxicidade , Mecanismos de Defesa , Perfilação da Expressão Gênica , Humanos , TranscriptomaRESUMO
Mitochondrial genomes (mitogenomes) help advance our learning of molecular evolution and phylogenetic relationships. The mitogenome of H. latimera is 16,246 bp in length, which typically contains 37 animal mitogenome genes consisting of 13 protein-coding genes (PCGs), two rRNA genes, and 22 tRNA genes, as well as a control region. The AT content of H. latimera is 69.1%. The A + T skew of the mitogenome of H. latimera was slightly negative (-0.017). The size of Thirteen PCGs is from 162 bp to 1731 bp. Twenty-two tRNA genes ranged from 62 to 73 bp and were highly A + T biased. All tRNA genes owed a typical cloverleaf structure, not including the trnS1 gene lacking a dihydroxyuridine arm. One PCG, two rRNAs, and 12 of the tRNAs were rearranged compared to the pancrustacean gene order. Phylogenetic analysis revealed the locationt of H. latimera among the Varunidae family.
Assuntos
Braquiúros/genética , Genoma Mitocondrial , Animais , Braquiúros/classificação , Proteínas Mitocondriais/genética , Filogenia , RNA de Transferência/genéticaRESUMO
Procambarus clarkii is one of the most important aquatic invertebrates in China and has high commercial value. However, aquaculture has suffered great economic loss due to outbreaks of infectious diseases in P. clarkii. To identify red swamp crayfish related proteins involved in the response to bacterial infection, we analysed immune-related proteins following lipopolysaccharide (LPS) stimulation by quantitative proteomics. The proteome of the hepatopancreas of P. clarkii challenged with LPS and phosphate-buffered saline was analysed to evaluate the immune response. Based on liquid chromatography coupled with tandem mass spectrometry, 16 upregulated and 29 downregulated proteins were identified. A Gene Ontology analysis demonstrated 5 biological process, 11 cellular component, and 6 molecular function subcategories. The Kyoto Encyclopedia of Genes and Genomes pathway enrichment analysis indicated that the identified proteins were mainly involved in metabolism, phagosome, and ribosome. Real-time quantitative reverse transcription-PCR revealed that eight immune-related genes were upregulated after LPS stimulation compared to the control. Taken together, the data enhance our understanding of the immune response of crayfish to LPS.
Assuntos
Astacoidea/imunologia , Hepatopâncreas/imunologia , Lipopolissacarídeos/imunologia , Animais , Aquicultura , Proteínas de Artrópodes/genética , Proteínas de Artrópodes/metabolismo , Astacoidea/genética , Perfilação da Expressão Gênica , Regulação da Expressão Gênica/imunologia , Hepatopâncreas/metabolismo , ProteômicaRESUMO
The mitochondrial genome (mitogenome) can provide important information for understanding phylogenetic analysis and molecular evolution. Herein, we amplified the complete mitogenome sequence of Pelteobagrus fulvidraco. The mitogenome was 16,526â¯bp in length and included 13 protein-coding genes (PCGs), 22 transfer RNA genes, two ribosomal RNA genes and a non-coding control region (D-loop). Both the organization and location of genes in the mitogenome were consistent with those from Siluriformes fishes previously published in GenBank. The phylogenetic relationships based on Bayesian inference (BI) and Maximum likelihood (ML) methods showed that P. fulvidraco has close relationships with Pelteobagrus eupogon and Tachysurus intermedius, suggesting that P. fulvidraco belongs to Tachysurus. This study provides evidence that Tachysurus, Pseudobagrus and Leiocassis do not form monophyly, but that these three genera form a monophyletic group. Our results provide reference for further phylogenetic research of the Bagridae species.
Assuntos
Peixes-Gato/genética , Genoma Mitocondrial , Animais , Peixes-Gato/classificação , Proteínas de Peixes/genética , Filogenia , RNA Ribossômico/genética , RNA de Transferência/genéticaRESUMO
In this study, we identified a fish-specific Toll-like receptor (TLR) in Pelteobagrus fulvidraco, an economically important freshwater fish in China. This TLR, PfTLR26, was shown to be encoded by a 3084 bp open reading frame (ORF), producing a polypeptide 1027 amino acids in length. The PfTLR26 protein contains a signal peptide, eight leucine-rich repeat (LRR) domains, two LRR_TYP domains in the extracellular region, and a Toll/interleukin (IL)-1 receptor (TIR) domain in the cytoplasmic region, consistent with the characteristic TLR domain architecture. This predicted 117.1â¯kDa protein was highly homologous to those of other fish, with phylogenetic analysis revealing the closest relation to TLR26 of Ictalurus punctatus. Real-time quantitative reverse transcription-PCR (qRT-PCR) analysis showed that the PfTLR26 gene was expressed in all tissues tested, with the highest expression levels seen in the head kidney and blood, and the lowest seen in muscle. PfTLR26 exhibited significant upregulation in liver, spleen, head kidney, and blood at different time points following challenge with the common TLR agonists lipopolysaccharide (LPS) and polyriboinosinic polyribocytidylic acid (Poly I:C). Taken together, these results suggest that PfTLR26 may be an important component of the P. fulvidraco innate immune system, participating in the transduction of TLR signaling under pathogen stimulation.
Assuntos
Peixes-Gato/imunologia , Imunidade Inata , Receptores Toll-Like/genética , Receptores Toll-Like/imunologia , Animais , Peixes-Gato/genética , Clonagem Molecular , Doenças dos Peixes/imunologia , Perfilação da Expressão Gênica , Regulação da Expressão Gênica , Lipopolissacarídeos/farmacologia , Poli I-C/farmacologia , RNA MensageiroRESUMO
To learn more about red swamp crayfish related genes in response to bacterial infections, we investigated immune-related genes induced by lipopolysaccharide (LPS) in the hepatopancreas using high-throughput sequencing method. In present the study, a total of 55,107 unigenes were identified, with an average length of 678 bp. A total of 2215 differentially expressed genes (DEGs) were found, including 669 up-regulated genes and 1546 down-regulated genes. The result of Gene ontology (GO) analysis revealed that 3017 DEGs were enriched in 19 biological process subcategories, 17 cellular component subcategories and 15 molecular function subcategories. The top 20 Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways showed that "ribosome" was the most abundant group, which had 34 DEGs. KEGG enrichment analysis identified several immune response pathways. Real-time quantitative reverse transcription-PCR (qRT-PCR) results exhibited that several immune responsive genes were greatly up-regulated following LPS stimulation as observed in the results of high-throughput sequencing. Overall, this study provides new insight into the immune defense mechanisms of P. clarkii against LPS infection.
Assuntos
Astacoidea/genética , Astacoidea/imunologia , Lipopolissacarídeos/administração & dosagem , Transcriptoma , Animais , Astacoidea/efeitos dos fármacos , Perfilação da Expressão Gênica , Ontologia Genética , Sequenciamento de Nucleotídeos em Larga EscalaRESUMO
Because of the high protein content and rich meat quality of crayfish Procambarus clarkii, it has become widely popular in China in recent years and has a high economic value. When P. clarkii is stimulated by heavy metals, it reacts to oxidation. P. clarkii has evolved antioxidant defense systems, including antioxidant enzymes such as catalase (CAT). The hexavalent form of Cr (VI) is a pathogenic factor that is of particular concern in aqueous systems because of its great toxicity to living organisms. In this study, we characterized the transcriptome of P. clarkii using a RNA sequencing method and performed a comparison between K2Cr2O7-treated samples and controls. In total, 34,237 unigenes were annotated. We identified 5098 significantly differentially expressed genes (DEGs), including 2536 and 2562 were significantly up-regulated and down-regulated, respectively. In addition, quantitative real time-PCR (qRT-PCR) confirmed the up-regulation of a random selection of DEGs. Our results contribute to a more comprehensive understanding of the antioxidant defense system used by P. clarkii in response to heavy metal stress.
Assuntos
Astacoidea/efeitos dos fármacos , Cromatos/toxicidade , Compostos de Potássio/toxicidade , Poluentes Químicos da Água/toxicidade , Animais , Antioxidantes/metabolismo , Astacoidea/genética , Astacoidea/metabolismo , Perfilação da Expressão Gênica , TranscriptomaRESUMO
Procambarus clarkii is one of the most economically important species in Chinese aquaculture, and is widely cultured. Infection of P. clarkii populations with bacterial pathogens causes high mortality and great economic loss, therefore disease control is of significant economic importance. P. clarkii is a model system for studying immune responses in invertebrates, and its immune system consists solely of the innate response. In the present study, we examined gene expression related to immune function in P. clarkii in response to pathogen challenge. The transcriptome of hepatopancreas tissue from P. clarkii challenged with peptidoclycan (PGN) was analyzed and compared to control specimens. After assembly and annotation, 48,661 unigenes were identified with an average length of 671.54 bp. A total of 2533 differentially expressed genes (DEGs) were obtained, including 765 significantly up-regulated unigenes and 1757 significantly down-regulated unigenes. Gene ontology (GO) analysis demonstrated 19 biological process subcategories, 16 cellular component subcategories, and 17 molecular function subcategories that were enriched among these DEGs. Enrichment analysis using the Kyoto Encyclopedia of Genes and Genomes (KEGG) database revealed enrichment among immune responses pathways. Taken together, this study not only enriches the existing P. clarkii transcriptome database, but also elucidates immune responses of crayfish that are activated in response to PGN challenge.
Assuntos
Astacoidea/genética , Perfilação da Expressão Gênica , Hepatopâncreas/efeitos dos fármacos , Peptidoglicano/farmacologia , Animais , Astacoidea/imunologia , Ontologia Genética , Hepatopâncreas/imunologiaRESUMO
Iron in excess can have toxic effects on living organisms. In China, the freshwater crayfish Procambarus clarkii is a source of aquatic food with high-quality protein and has significant commercial value. P. clarkii shows oxidative stress on exposure to heavy metals, and antioxidant enzymes, such as ubiquitination enzymes and proteasomes, play important roles in oxidative stress. To understand the antioxidant defense system of P. clarkii, we analyzed the hepatopancreas transcriptomes of P. clarkii after stimulation with FeCl3. In total, 5199 differentially expressed genes (DEGs) were identified (2747 upregulated and 2452 downregulated). GO analysis revealed that these DEGs belonged to 16 cellular component, 16 molecular function, and 19 biological process subcategories. A total of 1069 DEGs were classified into 25 categories by using COG. Some antioxidant defense pathways, such as "Ubiquitin mediated proteolysis" and "Glutathione metabolism," were identified using KEGG. In addition, quantitative real time-PCR (qRT-PCR) substantiated the up-regulation of a random selection of DEGs including antioxidant and immune defense genes. We obtained information for P. clarkii transcriptome databases and new insights into the responses of P. clarkii hepatopancreas to heavy metals.
Assuntos
Antioxidantes/metabolismo , Astacoidea/efeitos dos fármacos , Compostos Férricos/toxicidade , Hepatopâncreas/efeitos dos fármacos , Estresse Oxidativo/efeitos dos fármacos , Transcriptoma/efeitos dos fármacos , Animais , Astacoidea/genética , China , Perfilação da Expressão Gênica , Hepatopâncreas/metabolismo , Estresse Oxidativo/genética , Distribuição Aleatória , Reação em Cadeia da Polimerase em Tempo RealRESUMO
The mudflat crab Helice tientsinensis is one of the most economically important aquaculture species in China. Nevertheless, it is susceptible to various diseases caused by viruses, bacteria and rickettsia-like organisms. A better understanding of the immune system and genes related to the responses to bacterial and viral infection is required. Herein, the hepatopancreas transcriptome of H. tientsinensis was analyzed by comparing control and lipopolysaccharide (LPS)-stimulated RNA-Seq data, yielding 91,885,038 bp and 13.78â¯Gb of clean reads. Following assembly and annotation, 93,207 unigenes with an average length of 883 bp were identified, of which 31,674 and 13,700 were annotated in Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) databases, respectively. Following LPS, 4845 differentially expressed genes (DEGs) were identified, of which 2491 and 2354 were up- and down-regulated, respectively. To further investigate immune-related DEGs, KEGG enrichment analysis identified immune response pathways, most notably the peroxisome and Toll-like receptor signaling pathways. Quantitative real time-PCR (qRT-PCR) confirmed the up-regulation of a random selection of DEGs. This systematic transcriptomic analysis of the innate immune pathway in H. tientsinensis expands our understanding of the immune system in crabs.
Assuntos
Proteínas de Artrópodes/genética , Braquiúros/genética , Braquiúros/imunologia , Hepatopâncreas/metabolismo , Animais , Perfilação da Expressão Gênica , Lipopolissacarídeos/farmacologiaRESUMO
The yellow catfish, Pelteobagrus fulvidraco, has been recognized as an important freshwater aquaculture species in Eastern and Southeast Asia. To gain a better understanding of the immune response in P. fulvidraco, we analyzed its transcriptome following stimulation with lipopolysaccharide (LPS). Phosphate buffer saline (PBS) was used as control. Following assembly and annotation, 72,152 unigenes with an average length of 1090 bp were identified. A total of 370 differentially expressed genes (DEGs) in the P. fulvidraco were observed at 12 h post LPS treatment, including 197 up-regulated genes and 173 down-regulated genes. Clusters of Orthologous Groups of proteins (KOG/COG) annotation demonstrated that a total of 18,819 unigenes classified into 26 categories. Gene ontology (GO) analysis revealed 20 biological process subcategories, 7 cellular component subcategories and 20 molecular function subcategories. The Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis identified immune responses pathways. Quantitative reverse transcription polymerase chain reaction measured the expression of 18 genes involved in the immune response. CXCL2-like chemokine (CXCL2), goose-type lysozyme (LYZ G), and cathepsin K (CTSK) were significantly up-regulated. This study enriches the P. fulvidraco transcriptome database and provides insight into the immune response of P. fulvidraco against infection.
Assuntos
Peixes-Gato/genética , Peixes-Gato/imunologia , Proteínas de Peixes/genética , Regulação da Expressão Gênica/imunologia , Imunidade Inata/genética , Lipopolissacarídeos/farmacologia , Transcriptoma , Animais , Proteínas de Peixes/metabolismo , Fígado/efeitos dos fármacos , Fígado/imunologia , Reação em Cadeia da Polimerase Via Transcriptase Reversa/veterináriaRESUMO
In this study, the complete mitochondrial genome (mitogenome) of Clostera anachoreta (Lepidoptera: Notodontidae) was sequenced. It comprises 15,456 base pairs (bp), including 13 protein-coding genes (PCGs), two ribosomal RNAs (rRNAs), 22 transfer RNAs (tRNAs) and one non-coding control region (CR), as found in other lepidopterans. Gene order is identical to that of typical lepidopterans. There are 15 intergenic spacers ranging from 2 to 49bp, and 9 overlapping regions ranging from 1 to 8bp, occurring throughout the genome. The CR is 347bp long. All PCGs are initiated by ATN codons. We found a typical gene rearrangement in C. anachoreta (tRNAMet-tRNAIle-tRNAGln), which is different from ancestral insects (tRNAIle-tRNAGln-tRNAMet). The gene rearrangement can be explained by a duplication/random loss model. Phylogenetic analyses indicate that C. anachoreta belongs to Notodontidae, and that the monophyly of Lepidopteran families is well supported.
Assuntos
Genoma de Inseto , Genoma Mitocondrial , Mariposas/genética , Filogenia , Animais , Sequência de Bases , Ordem dos Genes , Análise de Sequência de DNARESUMO
The mitochondrial genome (mitogenome) provides important information for phylogenetic analysis and understanding evolutionary origins. Herein, we sequenced, annotated, and characterised the mitogenome of the crab Helice wuana to better understand its molecular evolution and phylogeny. The 16,359bp mitogenome includes 13 protein-coding genes (PCGs), 22 transfer RNA (tRNA) genes, two ribosomal RNA (rRNA) genes and one control region. The genome composition is highly A+T biased 68.42%, and exhibits a negative AT-skew (-0.036) and GC-skew (-0.269) among Brachyura crabs. Gene rearrangements were detected, as was tandem duplication followed by random loss, which explains the translocation of mitochondrial genes. Phylogenetic analysis showed that H. wuana and H. tientsinensis clustered on one branch with high nodal support values. These results confirm that the placement of H. wuana within the Varunidae family of Thoracotrematan crabs. This study will provided a better understanding for gene rearrangements and crab evolution in the further.
RESUMO
Gene arrangements in the mitochondrial genomes (mitogenomes) of insects are conserved across the major lineages, but can be rearranged within derived groups and may provide valuable phylogenetic characters. In this study, we sequenced the entire mitogenome of Parasa consocia, a moth of the family Limacodidae (Lepidoptera: Zygaenoidea). Compared with other lepidopterans and ancestral insects, the P. consocia mitogenome features a transfer RNA gene arrangement novel among lepidopterans between the ND3 and ND5 genes: RANSEF (the underline signifies an inverted gene), which differs from the ARNSEF arrangement of ancestral insects. This rearrangement can be explained by the tandem duplication-random loss model. We inferred a phylogenetic hypothesis for the lepidopteran superfamily based on mitochondrial amino-acid sequences using the Bayesian-inference and maximum-likelihood methods. Our results showed that P. consocia belongs to the Zygaenoidea superfamily and supported the following phylogenetic relationship: Yponomeutoidea + (Tortricoidea + Zygaenoidea + (Papilionoidea + (Pyraloidea + (Noctuoidea + (Geometroidea + Bombycoidea)))))). Comparative analyses indicated that mitogenomes are a useful phylogenetic tool at the subfamily level within the order Lepidoptera. Our findings also suggest that mitogenomes are likely to represent a valuable tool for systematics in other groups of lepidopterans.
Assuntos
Ordem dos Genes/genética , Genoma Mitocondrial/genética , RNA de Transferência/genética , Animais , Mariposas , FilogeniaRESUMO
Hepcidin is a small, cysteine-rich antimicrobial peptide with a highly conserved ß-sheet structure that plays a vital role in innate host immunity against pathogenic organisms. In this study, a hepcidin gene was identified in Pelteobagrus fulvidraco, an economically important freshwater fish in China. The gene is named PfHep. The complete PfHep cDNA was 723 bp, including a 5'-untranslated region (UTR) of 102 bp, a 3'-UTR of 339 bp and an open reading frame of 282 bp encoding a polypeptide of 93 amino acids, which includes a predicted signal peptide and the Hepcidin domain. The predicted mature, cationic PfHep protein has a typical hepcidin RX (K/R)R motif and eight conserved cysteine residues. The deduced PfHep protein sequence has 70%, 54% and 39% percent identity with hepcidins from Ictalurus punctatus, Danio rerio, and Homo sapiens, respectively. The predicted tertiary structure of PfHep is very similar to that of hepcidin in other animals. Phylogenetic analysis revealed that PfHep is closely related to the hepcidins of I. punctatus and I. furcatus. Real-time quantitative reverse transcription-PCR showed that the PfHep gene was expressed most in liver of healthy P. fulvidraco, and expressed to some extent in all the tissues tested. After challenge with lipopolysaccharide and polyriboinosinic:polyribocytidylic acid (poly I:C), respectively, the expression levels of PfHep were markedly upregulated in liver, spleen, head kidney and blood at different time points. Together these results imply that PfHep may be an important component of the innate immune system and be involved in immune defense against invading pathogens.
Assuntos
Peixes-Gato/genética , Proteínas de Peixes/genética , Regulação da Expressão Gênica , Hepcidinas/genética , Imunidade Inata , Sequência de Aminoácidos , Animais , Sequência de Bases , Peixes-Gato/imunologia , Peixes-Gato/metabolismo , Clonagem Molecular , DNA Complementar/genética , DNA Complementar/metabolismo , Proteínas de Peixes/química , Proteínas de Peixes/metabolismo , Perfilação da Expressão Gênica , Hepcidinas/química , Hepcidinas/metabolismo , Lipopolissacarídeos/farmacologia , Filogenia , Poli I-C/farmacologia , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Reação em Cadeia da Polimerase em Tempo Real/veterinária , Alinhamento de Sequência/veterináriaRESUMO
Yellow catfish (Pelteobagrus fulvidraco) is one of the most important economic freshwater species in China. However, infection by bacterial pathogenic diseases has caused high mortality and great economic loss in aquaculture. It is necessary for disease control to know more about the P. fulvidraco immune system and its related genes in response to bacterial or viral infections. In this study, the transcriptomic profiles of liver from P. fulvidraco stimulated by polyriboinosinic polyribocytidylic acid (poly I:C) was analyzed using high-throughput sequencing method. After assembly and annotation, total 67,447 unigenes were acquired, with an average length of 1091 bp. Under the infection of poly I:C, 522 differentially expressed genes (DEGs) were identified, including 307 up-regulated genes and 215 down-regulated genes. To further investigate the immune-related DEGs, Gene ontology (GO) enrichment and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment were performed. The result of GO enrichment indicated gene response to external stimulus, regulation of response to stimulus, cellular response to stimulus, immune response and immune system progress. Significant KEGG enrichment analysis identified major immune related pathways. Quantitative reverse transcription polymerase chain reaction (qRT-PCR) analysis revealed that 13 immune response genes were identified to be up-regulated after 12 h of poly I:C stimulation compared to controls. Taken together, the results of our study are beneficial for better understanding of the immune system and defense mechanisms of yellow catfish in response to poly I:C infection.