Exposure of zebrafish larvae to 3g and 5g hyper gravity between 5-6 days post-fertilization.
Ontology highlight
ABSTRACT: The general objective of the study was to determine modulation of gene expression by environmental factors, with a special emphasis on bone formation. For this reason, the specific period of treatment was chosen between 5-6 days post-fertilization (dpf), when bone formation and calcification are taking place. Zebrafish larvae were placed at 5 dpf into a Large Diameter Centrifuge and brought to a gravitational force of 3g or 5g for 24 hours. We show that this treatment causes a clear increase of bone formation, as illustrated by cranial skeleton staining of the bone matrix by Alizarin Red, by morphometric analysis of the resulting images and by gene expression studies of selected genes. Thus, a whole genome micro-array experiment was conducted to identify genes that may be involved in the observed effect on bone formation.
Project description:The general objective of the study was to determine modulation of gene expression by environmental factors, with a special emphasis on bone formation. For this reason, the specific period of treatment was chosen between 5-6 days post-fertilization (dpf), when bone formation and calcification are taking place. We show that treatment with Para-Thyroid Hormone (PTH) causes a clear decrease of bone formation, as illustrated by cranial skeleton staining of the bone matrix by Alizarin Red, by morphometric analysis of the resulting images and by gene expression studies of selected genes. Thus, a whole genome micro-array experiment was conducted to identify genes that may be involved in the observed effect on bone formation.
Project description:The general objective of the study was to determine modulation of gene expression by environmental factors, with a special emphasis on bone formation. For this reason, the specific period of treatment was chosen between 5-6 days post-fertilization (dpf), when bone formation and calcification are taking place. We show that treatment with Vitamin D3 (VitD3) causes a clear increase of bone formation, as illustrated by cranial skeleton staining of the bone matrix by Alizarin Red, by morphometric analysis of the resulting images and by gene expression studies of selected genes. Thus, a whole genome micro-array experiment was conducted to identify genes that may be involved in the observed effect on bone formation.
Project description:The general objective of the study was to determine modulation of gene expression by environmental factors, with a special emphasis on bone formation. For this reason, the specific period of treatment was chosen between 5-6 days post-fertilization (dpf), when bone formation and calcification are taking place. This experiment was designed as a new type of gravitational experiment, which we like to call \relative microgravity\, referring to the fact that the larvae first grow in hyper gravity for 5 days and are then returned to 1g normal gravity for 1 day. Zebrafish embryos were placed on a Large Diameter Centrifuge at 3 hpf, brought to a gravitational force of 3 g until 5 dpf. Reference embryos were kept in parallel at 1g (Inc). At 5dpf, one batch was left at 3g (3g), one batch was returned to 1g (3g>1g), while a third batch was returned to 1g, but left on the axis of the centrifuge (Axe; 3g>Axe). The experiment was repeated 4 times, each time with 4 batches of 60 larvae.
Project description:The general objective of the study was to determine modulation of gene expression by environmental factors, specifically simulation of microgravity, with a special emphasis on bone formation. For this reason, the specific period of treatment was chosen between 5-6 days post-fertilization (dpf), when bone formation and calcification are taking place. Zebrafish larvae were placed at 5 dpf into a clinostat (CLINO) for 24 hours, which was shown to simulate microgravity by the specific rotational movements it generates. We show that CLINO exposure causes a clear decrease of bone formation, as illustrated by cranial skeleton staining of the bone matrix by Alizarin Red, by morphometric analysis of the resulting images. Thus, a whole genome micro-array experiment was conducted to identify genes that may be involved in the observed effect on bone formation.
Project description:Autosomal optic atrophy (AOA) is a form of hereditary optic neuropathy characterized by the irreversible and progressive degermation of the retinal ganglion cells. Most cases of AOA are associated with a single dominant mutation in OPA1, which encodes a protein required for fusion of the inner mitochondrial membrane. It is unclear how loss of OPA1 leads to neuronal death, and despite ubiquitous expression appears to disproportionately affect the RGCs. This study introduces two novel in vivo models of OPA1-mediated AOA, including the first developmentally viable vertebrate Opa1 knockout (KO). These models allow for the study of Opa1 loss in neurons, specifically RGCs. Though survival is significantly reduced in Opa1 deficient zebrafish and Drosophila, both models permit the study of viable larvae. Moreover, zebrafish Opa1 KO larvae show impaired visual function but unchanged locomotor function, indicating that retinal neurons are particularly sensitive to Opa1 loss. Proteomic profiling of both models reveals marked disruption in protein expression associated with mitochondrial function, consistent with an observed decrease in mitochondrial respiratory function. Similarly, mitochondrial fragmentation and disordered cristae organization were observed in neuronal axons in both models highlighting Opa1’s highly conserved role in regulating mitochondrial morphology and function in neuronal axons. Importantly, in Opa1 deficient zebrafish, mitochondrial disruption and visual impairment precede degeneration of RGCs. These novel models mimic key features of AOA and provide valuable tools for therapeutic screening. Our findings suggest that therapies enhancing mitochondrial function may offer a potential treatment strategy for AOA.
Project description:Transcriptional Regulation in Testis Associated with Developmental and Reproductive Effects in Male Zebrafish Exposed to Natural Mixtures of Persistent Organic Pollutants from Mjosa Lake
Project description:The role of deiodinase-mediated TH effects in early vertebrate development is only partially understood. Therefore, we investigated the role of deiodinases during early development of zebrafish until 96 hours post fertilization at the level of the transcriptome, biochemistry, morphology and physiology using morpholino (MO) knockdown. Knockdown of D1+D2 (D1D2MO) and knockdown of D3 (D3MO) both resulted in transcriptional regulation of metabolism and (muscle) development in abdomen and tail, together with reduced growth, impaired swim bladder inflation, reduced protein content and reduced motility. The reduced growth and impaired swim bladder inflation in D1D2MO could be due to lower levels of T3 which is known to drive growth and development. The pronounced upregulation of a large number of transcripts coding for key proteins in ATP-producing pathways in D1D2MO could reflect a compensatory response to a decreased metabolic rate, also typically linked to hypothyroidy. Compared to D1D2MO, the effects were more pronounced or more frequent in D3MO, in which hyperthyroidy is expected. More specifically, increased heart rate, delayed hatching and increased carbohydrate content were observed only in D3MO. An increase of the metabolic rate, a decrease of the metabolic efficiency and a stimulation of gluconeogenesis using amino acids as substrates may have been involved in the observed reduced protein content, growth and motility in D3MO larvae. Furthermore, expression of transcripts involved in eye development and phototransduction was decreased in both knockdown conditions, suggesting that both may impair eye development and function. This study provides new insights, not only into the role of deiodinases, but also into the importance of a correct TH balance during vertebrate embryonic development. A-optimal design. Experimental design, D1D2MO vs SCMO and D3MO vs SCMO. Biological replicates: 4 SCMO, 4 D1D2MO, 4 D3MO
Project description:The role of deiodinase-mediated TH effects in early vertebrate development is only partially understood. Therefore, we investigated the role of deiodinases during early development of zebrafish until 96 hours post fertilization at the level of the transcriptome, biochemistry, morphology and physiology using morpholino (MO) knockdown. Knockdown of D1+D2 (D1D2MO) and knockdown of D3 (D3MO) both resulted in transcriptional regulation of metabolism and (muscle) development in abdomen and tail, together with reduced growth, impaired swim bladder inflation, reduced protein content and reduced motility. The reduced growth and impaired swim bladder inflation in D1D2MO could be due to lower levels of T3 which is known to drive growth and development. The pronounced upregulation of a large number of transcripts coding for key proteins in ATP-producing pathways in D1D2MO could reflect a compensatory response to a decreased metabolic rate, also typically linked to hypothyroidy. Compared to D1D2MO, the effects were more pronounced or more frequent in D3MO, in which hyperthyroidy is expected. More specifically, increased heart rate, delayed hatching and increased carbohydrate content were observed only in D3MO. An increase of the metabolic rate, a decrease of the metabolic efficiency and a stimulation of gluconeogenesis using amino acids as substrates may have been involved in the observed reduced protein content, growth and motility in D3MO larvae. Furthermore, expression of transcripts involved in eye development and phototransduction was decreased in both knockdown conditions, suggesting that both may impair eye development and function. This study provides new insights, not only into the role of deiodinases, but also into the importance of a correct TH balance during vertebrate embryonic development. A-optimal design. Experimental design, D1D2MO vs SCMO and D3MO vs SCMO. Biological replicates: 4 SCMO, 4 D1D2MO, 4 D3MO
Project description:Transcriptional Regulation in liver and ovary associated with developmental and reproductive effects in female Zebrafish exposed to natural mixtures of persistent organic pollutants from Lake Mjosa or Lake Losna