Project description:Gene set and sub-network enrichment analysis provides an integrated approach for identifying gene regulatory networks underlying development. Anuran development is a coordinated process, and levels of mRNA are first dominated by maternally deposited genes, followed by active transcription of embryonic genes as the embryo undergoes morphogenesis and organ formation. The objectives of this study were to characterize early gene regulatory networks underlying Silurana tropicalis development. A custom Agilent 4 x 44 K microarray was developed to characterize networks during early development (1, 17, 36, 96 hpf). Cluster analysis revealed that each stage showed unique gene expression profiles and that 1 hpf was most different than the other three stages. There were > 8000 unique gene probes (p<0.01, FDR = 5%) that were differentially expressed between 1 hpf (2 cell stage) and 17 hpf and > 2000 gene probes differentially expressed between 36 hpf and 96 hpf. Genes higher in abundance (>100-fold) at 1 hpf compared to 17 hpf included oocyte-specific histone RNA stem-loop-binding protein 2, mitogen-activated protein kinase 14, and cyclin B5, suggesting these transcripts are maternally inherited or actively transcribed at fertilization. Gene ontology revealed that genes involved in nucleosome assembly, cell division, pattern specification, neurotransmission, and general metabolism were increasingly regulated throughout development, consistent with active development. In the period between 17-36 hpf, gene networks that play a role in organogenesis and organ function, including those related to the heart (heart morphogenesis, central nervous system (olfactory bulb development, dopamine metabolism), and kidney (renal reabsorption, water balance) were activated while between 36-96 hpf, networks involving in gut development, immune responses, lipid metabolism, hormone signaling, and brain development were prevalent. This study increases understanding of the spatiotemporal S. tropicalis embryonic development using gene regulatory networks. Gene expression analysis was performed with four biological replicates for four developmental stages (n = 16). Stages were NF stages 2, 16, 34, and 46.
Project description:Gene set and sub-network enrichment analysis provides an integrated approach for identifying gene regulatory networks underlying development. Anuran development is a coordinated process, and levels of mRNA are first dominated by maternally deposited genes, followed by active transcription of embryonic genes as the embryo undergoes morphogenesis and organ formation. The objectives of this study were to characterize early gene regulatory networks underlying Silurana tropicalis development. A custom Agilent 4 x 44 K microarray was developed to characterize networks during early development (1, 17, 36, 96 hpf). Cluster analysis revealed that each stage showed unique gene expression profiles and that 1 hpf was most different than the other three stages. There were > 8000 unique gene probes (p<0.01, FDR = 5%) that were differentially expressed between 1 hpf (2 cell stage) and 17 hpf and > 2000 gene probes differentially expressed between 36 hpf and 96 hpf. Genes higher in abundance (>100-fold) at 1 hpf compared to 17 hpf included oocyte-specific histone RNA stem-loop-binding protein 2, mitogen-activated protein kinase 14, and cyclin B5, suggesting these transcripts are maternally inherited or actively transcribed at fertilization. Gene ontology revealed that genes involved in nucleosome assembly, cell division, pattern specification, neurotransmission, and general metabolism were increasingly regulated throughout development, consistent with active development. In the period between 17-36 hpf, gene networks that play a role in organogenesis and organ function, including those related to the heart (heart morphogenesis, central nervous system (olfactory bulb development, dopamine metabolism), and kidney (renal reabsorption, water balance) were activated while between 36-96 hpf, networks involving in gut development, immune responses, lipid metabolism, hormone signaling, and brain development were prevalent. This study increases understanding of the spatiotemporal S. tropicalis embryonic development using gene regulatory networks.
Project description:Dyes used in fabric and leather industry are being released and accumulated into Canadian ecosystems. Recent studies have demonstrated that dyes made of azo compounds significantly increase toxicity in biota, which is explained by their toxic metabolites (e.g., aromatic amines). The metabolites of azo compounds interact with hydrophobic surfaces of cell membranes causing expansion of the membrane which impede normal cellular functions. It has been suggested that this process leads to cell death due to improper ion balance. Currently, it is estimated that between 10 and 15% of azo dyes are released in the environment as effluent. The aim of this study was to evaluate toxicity and gene networks altered by azo compounds in amphibians using ecotoxicogenomic approaches. Larvae of the frog Silurana tropicalis (Western clawed frog) were exposed to sediment contaminated to 887 ppm Disperse Yellow 7 (DY7). Larvae were exposed from Nieuwkoop-Faber developmental stage 12 to 46. Data suggest that the azo dye DY7 induced cellular stress and interfered with androgen biosynthesis in early tadpole development. At exposure completion, RNA was isolated from whole larvae and quality was ascertained using bioanalyzer analysis. A custom Agilent 4 X 44 K microarray for S. tropicalis was used to characterize gene regulatory networks underlying toxicity. This study presents the transcriptional regulatory pathways affected by DY7 in S. tropicalis early development. Embryos were exposed to the DY7 dye during development. There were 4 control groups exposed and 4 treatment groups exposed.
Project description:Dyes used in fabric and leather industry are being released and accumulated into Canadian ecosystems. Recent studies have demonstrated that dyes made of azo compounds significantly increase toxicity in biota, which is explained by their toxic metabolites (e.g., aromatic amines). The metabolites of azo compounds interact with hydrophobic surfaces of cell membranes causing expansion of the membrane which impede normal cellular functions. It has been suggested that this process leads to cell death due to improper ion balance. Currently, it is estimated that between 10 and 15% of azo dyes are released in the environment as effluent. The aim of this study was to evaluate toxicity and gene networks altered by azo compounds in amphibians using ecotoxicogenomic approaches. Larvae of the frog Silurana tropicalis (Western clawed frog) were exposed to sediment contaminated to 887 ppm Disperse Yellow 7 (DY7). Larvae were exposed from Nieuwkoop-Faber developmental stage 12 to 46. Data suggest that the azo dye DY7 induced cellular stress and interfered with androgen biosynthesis in early tadpole development. At exposure completion, RNA was isolated from whole larvae and quality was ascertained using bioanalyzer analysis. A custom Agilent 4 X 44 K microarray for S. tropicalis was used to characterize gene regulatory networks underlying toxicity. This study presents the transcriptional regulatory pathways affected by DY7 in S. tropicalis early development.