Project description:Functional categorization of transcriptome in the species Symphysodon aequifasciatus Pellegrin 1904 (Perciformes: Cichlidae) exposed to benzo[a]pyrene and phenanthrene
Project description:The discus fish (Symphysodon aequifasciatus) is an ornamental fish, which occupies important position on the freshwater aquarium trade. We built two cDNA libraries from an adult male brain and an adult female brain, and performed RNA-sequencing for identifying sex-biased candidate genes , a total number of 40209 non-redundant genes (unigenes) were obtained, of which 250 unigenes were significant overexpressed in the male brain, and 436 unigenes were significant overexpressed in the female. A total of 439 miRNAs were identified, of which 60 miRNAs were differentially expressed between male brain and female brain. These results can provide important evidence for better understanding the molecular mechanisms of the brain's amphoteric dimorphism in discus fish
Project description:This study aims to evaluate the transcriptome alterations, through cDNA libraries, associated with the effects of the combination of two PAHs, benzo[a]pyrene (0.5μg/L) and phenanthrene (50μg/L), present in crude oil, on specimens of Symphysodon aequifasciatus (discus fish) after 48h of exposure. The cDNA libraries were constructed according to the SOLiDTM SAGETM protocol for sequencing in the SOLiD v.3 Plus sequencer. The results were analyzed by bioinformatics and differentially expressed genes were categorized using the gene ontology program (AmiGO v.1.8). The functional categories (terms) found in the gene ontology and the gene network generated using STRING software were used to predict the adverse effects in the liver. In the present study, 27,127 genes (compared to Danio rerio database) were identified. Considering only those genes with a p-value less than or equal to 0.05 and a greater than or equal to two-fold change in expression across libraries, we found 804 genes, 438 down-regulated (54%) and 366 up-regulated genes (46%), in the experimental group compared to the control group. Out of this total, 327 genes were successfully categorized, 174 down-regulated and 153 up-regulated genes, using gene ontology tool. The final confidence gene network, analyzed in STRING, was composed by 199 nodes of proteins, 124 of them resulted in 274 interactions. The results showed that even an acute exposure of 48 h caused metabolic change in response to environmental contaminants, resulting in changes of cell integrity, changes in oxidation-reduction processes, disturbances of intracellular signaling and changes in the immune response of discus fish. Also the gene network interactions have showed no central interplay cluster, exhibiting interconnected clusters interactions and sparsely connected sub-networks. These findings highlight that even an acute and sublethal exposure of PAHs can cause metabolism changes that may affect this fish species survival rates. Our findings using the SAGE-method and the SOLiD sequencer showed that this is a powerful tool for gene expression analysis in discus fish, a non-model organism.
Project description:This study aims to evaluate the transcriptome alterations, through cDNA libraries, associated with the effects of the combination of two PAHs, benzo[a]pyrene (0.5M-NM-<g/L) and phenanthrene (50M-NM-<g/L), present in crude oil, on specimens of Symphysodon aequifasciatus (discus fish) after 48h of exposure. The cDNA libraries were constructed according to the SOLiDTM SAGETM protocol for sequencing in the SOLiD v.3 Plus sequencer. The results were analyzed by bioinformatics and differentially expressed genes were categorized using the gene ontology program (AmiGO v.1.8). The functional categories (terms) found in the gene ontology and the gene network generated using STRING software were used to predict the adverse effects in the liver. In the present study, 27,127 genes (compared to Danio rerio database) were identified. Considering only those genes with a p-value less than or equal to 0.05 and a greater than or equal to two-fold change in expression across libraries, we found 804 genes, 438 down-regulated (54%) and 366 up-regulated genes (46%), in the experimental group compared to the control group. Out of this total, 327 genes were successfully categorized, 174 down-regulated and 153 up-regulated genes, using gene ontology tool. The final confidence gene network, analyzed in STRING, was composed by 199 nodes of proteins, 124 of them resulted in 274 interactions. The results showed that even an acute exposure of 48 h caused metabolic change in response to environmental contaminants, resulting in changes of cell integrity, changes in oxidation-reduction processes, disturbances of intracellular signaling and changes in the immune response of discus fish. Also the gene network interactions have showed no central interplay cluster, exhibiting interconnected clusters interactions and sparsely connected sub-networks. These findings highlight that even an acute and sublethal exposure of PAHs can cause metabolism changes that may affect this fish species survival rates. Our findings using the SAGE-method and the SOLiD sequencer showed that this is a powerful tool for gene expression analysis in discus fish, a non-model organism. Transcriptome analysis of differentially expressed genes in liver in benzo[a]pyrene and phenanthrene-exposed and non-exposed fish (N=6 per treatment)
Project description:Differential expression and correlation analysis of mRNA and miRNA based on Brain transcriptome in the discus fish (Symphysodon aequifasciatus)
Project description:With the goal of contributing to the taxonomy and systematics of the Neotropical cichlid fishes of the genus Symphysodon, we analyzed 336 individuals from 24 localities throughout the entire distributional range of the genus. We analyzed variation at 13 nuclear microsatellite markers, and subjected the data to Bayesian analysis of genetic structure. The results indicate that Symphysodon is composed of four genetic groups: group PURPLE-phenotype Heckel and abacaxi; group GREEN-phenotype green; group RED-phenotype blue and brown; and group PINK-populations of Xingú and Cametá. Although the phenotypes blue and brown are predominantly biological group RED, they also have substantial contributions from other biological groups, and the patterns of admixture of the two phenotypes are different. The two phenotypes are further characterized by distinct and divergent mtDNA haplotype groups, and show differences in mean habitat use measured as pH and conductivity. Differences in mean habitat use is also observed between most other biological groups. We therefore conclude that Symphysodon comprises five evolutionary significant units: Symphysodon discus (Heckel and abacaxi phenotypes), S. aequifasciatus (brown phenotype), S. tarzoo (green phenotype), Symphysodon sp. 1 (blue phenotype) and Symphysodon sp. 2 (Xingú group).