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 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. Largemouth bass fed diedrin for two months once a day ad libitium; 4 biological replicates for each group
Project description:Female largemouth bass were injected with 10mg/kg dieldrin and sacrificed after 7 days. Hypothalami were dissected and total RNA extracted for microarray analysis. Exposure to dieldrin induces neurotoxic effects in the vertebrate CNS and disrupts reproductive processes in teleost fish. Reproductive impairment observed in fish is likely the result of multiple mechanisms of action along the hypothalamic-pituitary-gonadal axis. To better elucidate the mode of action of dieldrin in the hypothalamus, we measured neurotransmitter levels and examined the transcriptomic response of female largemouth bass (LMB) to an acute treatment of dieldrin. Female LMB were injected with either vehicle or 10 mg/kg dieldrin and sacrificed after seven days. The neurotransmitter γ-aminobutyric acid was significantly elevated by approximately 25-30% in the hypothalamus and cerebellum but there was no change in dopamine levels in the hypothalamus, telencephalon, or cerebellum. We identified 270 transcripts (p<0.001) as being differentially regulated by dieldrin. Functional enrichment analysis identified transcription, DNA repair, ubiquitin pathway, cell communication, and phosphorylation as biological processes over-represented in the microarray analysis. Pathway analysis identified DNA damage, inflammation, regeneration, and Alzheimerâs disease as major cell processes and diseases affected by dieldrin. Using multiple bioinformatics approaches, this study demonstrates that the teleostean hypothalamus is a target for dieldrin-induced neurotoxicity and provides mechanistic evidence that dieldrin activates similar cell pathways and biological processes that are involved in the etiology of human neurological disorders. Key words: ubiquitin-proteasome pathway, mutagenicity, neurodegeneration, apoptosis, DNA damage Largemouth bass injected with single i.p. with 10 mg/kg diedrin; sacrificed 7 days later, hypothalamic tissue studied
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:This study examines the genomic effects of dieldrin in the hypothalamus of largemouth bass. Dieldrin is an insectide and organic pollutant.
Project description:White bass (Morone chrysops) are a popular sportfish throughout the southern United States, and one parent of the commercially successful hybrid striped bass (M. chrysops x M. saxatilis). Currently, white bass are cultured using diets formulated for other carnivorous fish, such as largemouth bass (Micropterus salmoides) or hybrid striped bass and contain a significant percentage of marine fish meal. Since there are no studies regarding the utilization of alternative proteins in this species, we evaluated global gene expression of white bass fed diets in which fish meal was partially or totally replaced by various combinations of soybean meal, poultry by-product meal, canola meal, soy protein concentrate, wheat gluten, or a commercial protein blend (Pro-Cision). Significant differential expressed genes and gene ontology of pairwise comparisons between control diet and each test diet are presented and discussed.
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).