Project description:This SuperSeries is composed of the following subset Series: GSE38456: Characterizing gene regulatory networks in the brain of largemouth bass inhabiting rivers containing high levels of methyl-mercury (lab study) GSE38458: Characterizing gene regulatory networks in the brain of largemouth bass inhabiting rivers containing high levels of methyl-mercury (field study) Refer to individual Series
Project description:Characterizing gene regulatory networks in the brain of largemouth bass inhabiting rivers containing high levels of methyl-mercury (field study)
Project description:Characterizing gene regulatory networks in the brain of largemouth bass inhabiting rivers containing high levels of methyl-mercury (lab study)
Project description:Background and Methods: High mercury (Hg) levels are a significant concern in many aquatic environments, and adverse effects of Hg exposure in fish can include altered behavior, reproduction, growth, and increased stress responses. In addition, human health concerns over Hg continue to warrant new research on its mechanisms of action. The objectives of this study were to investigate the impacts of Hg on the female largemouth bass (LMB) central nervous system transcriptome by conducting a laboratory injection experiment with 2.5 M-BM-5g/g body weight in addition to sampling LMB from an environment that contains high levels of Hg (St. MaryM-bM-^@M-^Ys River, Florida, USA). These animals were compared to LMB that inhibit river systems with lower Hg (Big Wekiva, Santa Fe and St. JohnM-bM-^@M-^Ys Rivers Florida, USA). A LMB 8 x 15 K microarray was used for hypothalamic (laboratory) and whole brain (field) transcriptomics analysis. Results: Mercury in the blood of LMB collected from St MaryM-bM-^@M-^Ys River was significantly elevated 3-fold (~ 0.1 ng Hg/ml blood) compared to LMB collected from the other three sites (~ 0.03 ng Hg/ml blood). In the hypothalamus of Hg injected LMB, there were 937 genes that showed differential expression (raw p = 0.05) but there were no probes that passed an FDR for multiple hypothesis correction. In contrast, in field collected LMB there were 2909 genes that that showed differential expression (raw p = 0.05) of which 38 were significant after correction for multiple hypothesis testing (FDR = 0.05). These included Hsp90 co-chaperone Cdc37, multicopper oxidase, mismatch repair protein Msh6, and 16 kDa heat shock protein A. Functional enrichment in whole brains of LMB collected from the field sites revealed that genes involved in the biological processes of protein folding and targeting, regulation of protein metabolic process, and protein degradation (i.e. ubiquitin cycle) were over-represented. Interestingly, gene set enrichment analysis identifed expression targets that were in common between the laboratory experiment (MeHg injected) and field collected LMB and these consisted of mainly homeobox transcription factors (PROP paired-like homeobox 1, LIM homeobox 3 and paired-like homeodomain 1 and 2). Lastly, prevalent themes emerged in the SNEA expression targets that included neuropeptide receptor signaling, steroid signaling, and structural components, such as beta-actin, integrins, and stress fibres. Conclusions: This study characterizes novel cell signaling pathways that underlie Hg toxicity in the teleostean central nervous system. field study with methyl mercury
Project description:We sequenced mRNA from 9 liver samples of juvenile largemouth bass (Micropterus salmoides) taken from different lead concentration exposure treatment fish and control fish to investigate the transcriptome and comparative expression profiles of largemouth bass liver undergoing lead exposure.
Project description:This study examines the genomic effects of dieldrin in the hypothalamus of largemouth bass. Dieldrin is an insectide and organic pollutant. Largemouth bass fed diedrin for two months once a day ad libitium; 4 biological replicates for each group
Project description:This SuperSeries is composed of the following subset Series: GSE38738: High contaminant loads in Lake Apopka mesocosms affect the ovarian transcriptome in largemouth bass [April] GSE38773: High contaminant loads in Lake Apopka mesocosms affect the ovarian transcriptome in largemouth bass [January] Refer to individual Series
Project description:This study examines the genomic effects of dieldrin in the hypothalamus of largemouth bass. Dieldrin is an insectide and organic pollutant.
Project description:Intensive aquaculture and environmental changes will inevitably lead to hypoxic stress for largemouth bass (Micropterus salmoides). To better understand the hypoxia responds mechanisms of largemouth bass, we compared the miRNA profile in liver under different environmental DO to determine which miRNAs are most affected during hypoxia. A total of 266 miRNAs were identified, and 84 miRNAs were differentially expressed compared with in control group. GO and KEGG analysis indicated that the miRNAs may play important roles in environment information processing. Specifically, we considered the VEGF signaling pathway, Phosphatidylinositol signaling system and MAPK signaling pathway, the results show that, the 13 miRNAs (miR-15b-5p, miR-30a-3p, miR-133a-3p, miR-19d-5p, miR-1288-3p, miR456, miR-96-5p, miR-23a-3p, miR-23b, miR-214, miR-24, miR-20a-3p and miR-2188-5p) involved in these three pathways are significantly down-regulated during hypoxia stress. And 12 target genes of these miRNAs were showed a higher degree of expression. We found the obvious negative correlation between miRNA and their target mRNAs, providing several miRNA-mRNA interaction networks in largemouth bass in response to hypoxia. Although relatively little information is currently available concerning the biological function of miRNAs identified to date, we strongly suggest that miRNAs play an important role in modulating gene expression involved in the physiological response to hypoxic stress in the fish liver.
Project description:A novel custom microarray for largemouth bass (Micropterus salmoides) was designed from sequences obtained from a normalized cDNA library using the 454 Life Sciences GS-20 pyrosequencer. The GS-20 yielded in excess of 58 million bases of high-quality sequence. The sequence information was combined with 2,616 reads obtained by traditional suppressive subtractive hybridizations to derive a total of 31,391 unique sequences. Annotation and coding sequences were predicted for these transcripts where possible. 16,350 annotated transcripts were selected as target sequences for the design of the custom largemouth bass oligonucleotide microarray. The microarray was validated by examining the transcriptomic response in male largemouth bass exposed to 17 -oestradiol. Transcriptomic responses were assessed in liver and gonad, and indicated gene expression profiles typical of exposure to oestradiol. The results demonstrate the potential to rapidly create the tools necessary to assess large scale transcriptional responses in non-model species, paving the way for expanded impact of toxicogenomics in ecotoxicology. Keywords: E2 exposure, array validation