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
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 This experiment tested two organs - liver and gonad from either E2-exposed or control fish, 4 fish (biological replicates) per treament (control and E2).
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 study examines the genomic effects of dieldrin in the hypothalamus of largemouth bass. Dieldrin is an insectide and organic pollutant.
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 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:Male largemouth bass were injected with 25 mg/kg MXC and sacrificed after 48 hours; liver dissected and used for total RNA extraction Keywords: Methoxychlor injection; single injection and time point The organochlorine pesticide methoxychlor (MXC) (1,1,1-trichloro-2,2-bis(p-methoxyphenyl)ethane) has been used increasingly as an insecticide since the banning of DDT, the primary advantage being that MXC is rapidly metabolized and does not show high levels of bioaccumulation in non-target organisms. However, studies have shown that MXC can be metabolized into additional metabolites, such as mono-demethylated 2-(p-hydroxyphenyl)-2-(p-methoxyphenyl)-1,1,1-trichloroethane (OH-MXC) and bis-demethylated 2,2-bis(p-hydroxyphenyl)-1,1,1-trichloroethane (HPTE), both of which are estrogenic in mammals. In addition, there is increased potential for disruptions to normal hepatic physiology (Schlenk et al., 1998; Stuchal et al., 2006). The objectives of the present study were to study the hepatic genomic response in male largemouth bass to an i.p. injection of MXC. We performed a microarray analysis on 25 mg/kg MXC 48 hour injection because there was a significant induction of ERα and ERβb mRNA in the liver which was comparable to a 48 hour 1 mg/kg injection of E2 (previous work done by Blum et al., 2008; Aquat Toxicol. 86(4), 459-469). We chose the liver because of the significant role this tissue plays in detoxification of contaminants and due to the high capacity to produce vitellogenin in response to estrogenic chemicals. We were also interested in comparing the genomic response of MXC to estradiol alone to identify putative candidate genes and pathways that may be specific to MXC and not due to direct estrogenic effects mediated via E2 receptors. Largemouth bass injected with single i.p. with 25 mg/kg methoxychlor; sacrificed 48 days later,liver tissue studied. 4 individual liver samples (control and treatment)
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.