Project description:We have employed whole genome microarray expression profiling as a discovery platform to identify the change of gene in zebrafish testes between the control and MCLR groups. zebrafish were exposed to 20 μg/L MCLR for 6 weeks. Fresh testes tissue samples from 5 individuals were collected as one sample. Expression of three genes (hsp70, fgf1a and tgfβ1) from this signature was quantified in the same RNA samples by real-time PCR, confirming the reliability of microarray analysis.
Project description:Sensitivity and throughput of transcriptomics and proteomomics technologies have advanced tremendously in recent years. With the use of deep sequencing of RNA samples (RNAseq) and mass spectrometry technology for protein identification and quantitation, it is now feasible to compare gene and protein expression on a massive scale and on any organism for which genomic data is available. Although these technologies are currently applied to many research questions in various model systems ranging from cell cultures to the entire organism level, there are few comparative studies of these technologies in the same system, let alone on the same samples. Here we present a comparison between gene and protein expression in zebrafish embryos, which is an upcoming model in disease studies. We compared Agilent custom made expression microarrays with Illumina deep sequencing for RNA analysis, showing as expected a high degree of correlation of expression of a common set of 15,927 genes. Gene expression was also found to correlate with the abundance of 1,017 quantified proteins, with several categories of genes as exceptions. These exceptions include ribosomal proteins, histones and vitellogenins, for which biological and technical explanations are discussed. By comparing state of the art transcriptomic and proteomic technologies on samples derived from the same group of organisms we have for the first time benchmarked the differences in these technologies with regard to sensitivity and bias towards detection of particular gene categories. Our datasets submitted to public repositories are a good starting point for researchers interested in disease progression in zebrafish at a stage of development highly suited for high throughput screening technologies. The transcriptomics data is deposited in NCBI GEO. Proteomics informatics: Spectra were identified by Mascot and validated by PeptideProphet and ProteinProphet in the Trans-Proteomic Pipeline (TPP). The main search parameters are: full tryptic specificity, precursor mass searched within -0.5 to +2.5 Da, product ions within [-0.5,0.5] Da and allowing for one missed cleavage. Carbamidomethylation was assumed as the only and fixed PTM.
Project description:The developmental origins of health and adult disease (DOHaD) hypothesis states that exposure to various environmental stressors early in life can elicit changes to the genome and epigenome thereby resulting in an increased susceptibility of a disease state during adulthood. Atrazine, a common herbicide used throughout the Midwestern United States for control of weeds on various crops frequently contaminates potable water supplies and is a suspected endocrine disrupting chemical. Studies suggest atrazine elicits reproductive dysfunction through the hypothalamus-pituitary-gonadal (HPG) axis. In previous studies, zebrafish were exposed to 0.3, 3, or 30 parts per billion (ppb; ug/L) atrazine through embryogenesis, rinsed, and allowed to mature to adulthood. A decrease in spawning was observed in adults with an embryonic exposure. In addition, adult females had an increase in progesterone and ovarian follicular atresia, alterations in levels of a serotonin metabolite and serotonin turnover in brain tissue, and transcriptome alterations in brain and ovarian tissue supporting neuroendocrine alterations from an embryonic atrazine exposure were reported. Furthermore, offspring of the exposed population exhibited morphological alterations. As reproductive dysfunction may also be influenced by males, this study assessed transcriptomic profiles of brain and testes, morphology, histology, and hormone levels in adult males exposed to atrazine during embryogenesis. Transcriptomic profiles of adult male brain tissue revealed alterations in genes associated with cell to cell signaling and interaction of neurotransmission, cell morphology, cellular assembly and organization of neurites, cellular function and maintenance of neuritogenesis and synaptogenesis, and molecular transport of hormones. In addition, the transcriptomic profiles of adult male testes tissue demonstrated alterations in genes associated with lipid metabolism, molecular transport of steroids, small molecule biochemistry of lipids, and cell morphology. The embryonic atrazine exposure resulted in no alterations in body or testes weight, gonadosomatic index, testes histology, or levels of 11-ketotestosterone or testosterone in adult male zebrafish. Thus, although the transcriptomics data indicate later-in-life alterations on the neuroendocrine system of adult males exposed to atrazine during embryogenesis, analysis of additional endpoints is needed to determine functional impairments. We treated zebrafish embryos from approximately 1 hour post fertilization through 72 hours post fertilization (embryogenesis) to 0, 0.3, 3, or 30 parts per billion (ppb) atrazine. Following the 72 hour exposure period, larave were rinsed and allowed to mature under normal conditions until adulthood (5-6 months post fertilization). At this time, zebrafish were bred weekly for three weeks in order to initiate breeding cycles. Following this peroid, gonadal tissue was disseceted and processed for transcriptomic analysis.
Project description:The developmental origins of health and adult disease (DOHaD) hypothesis states that exposure to various environmental stressors early in life can elicit changes to the genome and epigenome thereby resulting in an increased susceptibility of a disease state during adulthood. Atrazine, a common herbicide used throughout the Midwestern United States for control of weeds on various crops frequently contaminates potable water supplies and is a suspected endocrine disrupting chemical. Studies suggest atrazine elicits reproductive dysfunction through the hypothalamus-pituitary-gonadal (HPG) axis. In previous studies, zebrafish were exposed to 0.3, 3, or 30 parts per billion (ppb; ug/L) atrazine through embryogenesis, rinsed, and allowed to mature to adulthood. A decrease in spawning was observed in adults with an embryonic exposure. In addition, adult females had an increase in progesterone and ovarian follicular atresia, alterations in levels of a serotonin metabolite and serotonin turnover in brain tissue, and transcriptome alterations in brain and ovarian tissue supporting neuroendocrine alterations from an embryonic atrazine exposure were reported. Furthermore, offspring of the exposed population exhibited morphological alterations. As reproductive dysfunction may also be influenced by males, this study assessed transcriptomic profiles of brain and testes, morphology, histology, and hormone levels in adult males exposed to atrazine during embryogenesis. Transcriptomic profiles of adult male brain tissue revealed alterations in genes associated with cell to cell signaling and interaction of neurotransmission, cell morphology, cellular assembly and organization of neurites, cellular function and maintenance of neuritogenesis and synaptogenesis, and molecular transport of hormones. In addition, the transcriptomic profiles of adult male testes tissue demonstrated alterations in genes associated with lipid metabolism, molecular transport of steroids, small molecule biochemistry of lipids, and cell morphology. The embryonic atrazine exposure resulted in no alterations in body or testes weight, gonadosomatic index, testes histology, or levels of 11-ketotestosterone or testosterone in adult male zebrafish. Thus, although the transcriptomics data indicate later-in-life alterations on the neuroendocrine system of adult males exposed to atrazine during embryogenesis, analysis of additional endpoints is needed to determine functional impairments. We treated zebrafish embryos from approximately 1 hour post fertilization through 72 hours post fertilization (embryogenesis) to 0, 0.3, 3, or 30 parts per billion (ppb) atrazine. Following the 72 hour exposure period, larvae were rinsed and allowed to mature under normal conditions until adulthood (5-6 months post fertilization). At this time, zebrafish were bred weekly for three weeks in order to initiate breeding cycles. Following this peroid, gonadal tissue was dissected and processed for transcriptomic analysis.
Project description:ZBTB48 (also known as TZAP) is a transcription factor that has previously been reported to bind to telomeres and act as a negative regulator of telomere length in human cell lines. To explore whether transcription factor activity and telomere length regulation are conserved at the organismal level in vertebrates, we generated a zbtb48-/- zebrafish line via CRISPR‒Cas genome editing. The zbtb48-/- mutants displayed no obvious physical or behavioral abnormalities in the first two generations. We found no statistically significant changes in telomere length in first-generation adults. However, for the gene regulatory aspect of Zbtb48, similar to that in human cancer cell lines, we observed downregulation of mtfp1 at both the mRNA and protein levels in the zbtb48-/- mutants. This suggests that mtfp1 is an evolutionarily conserved regulatory target of Zbtb48. Further investigation of the spatiotemporal expression of zbtb48 in previously published zebrafish data revealed low transcript expression in diverse tissues, except in germline stem cells and gametocytes of the gonads. Notably, Mtfp1 protein downregulation was detected in the ovaries of 40 dpf zbtb48-/- mutants and in the testes of both 40 dpf and 10.5-month-old zbtb48-/- mutants.