Transcription profiling of Zebrafish 1 Day post amputation vehicle or beclomethasone exposed to study regeneration
ABSTRACT: Zebrafish caudal fin regeneration is an established model to study tissue regeneration. In order to identify novel molecular signaling pathways critical for regeneration, we developed a rapid throughput in vivo regeneration assay. We screened a 2000 member structurally diverse small molecule library, followed by assessment of regenerative progression at three days post amputation. A cluster of glucocorticoids was identified among the “positive hits”. To identify the molecular targets of the activated glucocorticoid receptor, microarray analysis was performed using RNA isolated from the regenerates of control and glucocorticoid exposed zebrafish. We identified 673 transcripts that were differentially regulated. The level of expression and spatial expression pattern of select genes were completed by qPCR and by in situ hybridization, respectively. Altogether, these studies demonstrate the power of chemical genetics to identify chemical probes and their targets which will provide a path towards defining conserved regenerative pathways. Experiment Overall Design: The caudal fin of zebrafish larvae at 2days post fertilization were amputated and exposed to vehicle control alone or Beclomethasone . Regenerating fins were isolated at 1days post amputation. Three replicates were collected at each time point. 150 fins were pooled to comprise one replicate.
Project description:Exposures to dioxin, including 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) cause a wide array of toxicities in vertebrates and is mostly considered to be mediated through the inappropriate activation of the aryl hydrocarbon receptor (Ahr) signaling pathway. Although transcriptional regulation by Ahr is widely studied, the molecular mechanisms responsible for the adverse outcomes after Ahr activation are largely unknown. To identify the important events downstream of AHR activation that play an actual role in the toxic responses, we employed the zebrafish caudal fin regeneration models since Ahr activation blocks the regenerative process. Zebrafish regenerate their caudal fins by an orchestrated progression of cell migration, differentiation and proliferation controlled by a multitude of signaling pathways. This complex process was exploited as an in vivo platform to identify cross talk between Ahr and other signaling pathways. Global genomic analysis was performed in the larval regenerating fin tissue after exposure to TCDD in order to identify genes differentially regulated after Ahr activation. Comparative toxicogenomic analysis revealed that both adult and larval fins respond to TCDD during regeneration with mis-expression of Wnt signaling pathway members and Wnt target genes. Experiment Overall Design: The caudal fin of zebrafish larvae at 2days post fertilization were amputated and exposed to vehicle control alone or TCDD. Regenerating fins were isolated at 2and 3 days post amputation. Three replicates were collected at each time point. 150 fins were pooled to comprise one replicate.
Project description:Zebrafish have the remarkable ability to regenerate body parts including the heart, spinal cord and fins by a process referred to as epimorphic regeneration. Recent studies have illustrated that similar to adult zebrafish, early life stage-larvae also possess the ability to regenerate the caudal fin. A comparative genomic analysis was used to determine the degree of conservation in gene expression among the regenerating adult caudal fin, adult heart and larval fin. Results indicate that these tissues respond to amputation/injury with strikingly similar genomic responses. Comparative analysis revealed raldh2, a rate-limiting enzyme for the synthesis of Retinoic acid (RA), as one of the highly induced genes across the three regeneration platforms. Experiment Overall Design: The caudal fin of zebrafish larvae at 2days post fertilization were amputated. Caudal fin tissue at 2dpf and regenerating fins were isolated at 1, 2and 3 days post amputation. Three replicates were collected at each time point. 150 fins were pooled to comprise one replicate.
Project description:Adult zebrafish can completely regenerate their caudal fin following amputation. This complex process is initiated by the formation of an epithelial would cap over the amputation site by 12 hours post amputation (hpa). Once the cap is formed, mesenchymal cells proliferate and migrate from sites distal to the wound plane and accumulate under the epithelial cap forming the blastemal structure within 48 hpa. Blastemal cells proliferate and differentiate, replacing the amputated tissues, which are populated with angiogenic vessels and innervating nerves during the regenerative outgrowth phase which is completed around 14 days post amputation (dpa). Regenerative outgrowth does not occur in TCDD-exposed zebrafish. To identify the molecular pathways that are perturbed by TCDD exposure, male zebrafish were i.p. injected with 50 ng/g TCDD or vehicle and caudal fins were amputated. Regenerating fin tissue was collected at 1, 3 and 5 dpa for mRNA abundance analysis. Microarray analysis and quantitative real time PCR revealed that wound healing and regeneration alone altered the expression of nearly 900 genes by at least two fold between 1 and 5 dpa. TCDD altered the abundance of 370 genes at least two fold. Among these, several known aryl hydrocarbon responsive genes were identified in addition to several genes involved in extracellular matrix composition and metabolism. The profile of misexpressed genes is suggestive of impaired cellular differentiation and extracellular matrix composition potentially regulated by Sox9b. Experiment Overall Design: Regenerating fins were isolated at 1, 3 and 5 days post amputation. Three replicates were collected at each time point. 10 fins were pooled to comprise one replicate. Fish were dosed at 0 days post amputation with vehicle control alone or 50 ng/g TCDD. Experiment Overall Design: 1 Day Post Amputation Vehicle Exposed: GSM85187, GSM85188, and GSM85189 Experiment Overall Design: 1 Day Post Amputation TCDD Exposed: GSM85190, GSM85191, and GSM85192 Experiment Overall Design: 3 Days Post Amputation Vehicle Exposed: GSM85193, GSM85194, and GSM85195 Experiment Overall Design: 3 Day Post Amputation TCDD Exposed: GSM85196, GSM85197, and GSM85198 Experiment Overall Design: 5 Days Post Amputation Vehicle Exposed: GSM85199, GSM85200, and GSM85201 Experiment Overall Design: 5 Days Post Amputation TCDD Exposed: GSM85202, GSM85203, and GSM85204
Project description:Previous studies of zebrafish caudal fin regeneration have shown that multiple genetic programs are moduled through regulatory factors. MicroRNAs are short highly conserved non-coding genes that suppress expression of target genes and thereby control multiple genetic programs. Given their important regulatory roles and evolutionary conservation, we hypothesize that microRNAs define a conserved genetic regulatory circuit important for appendage regeneration. We characterized microRNA expression during zebrafish caudal fin regeneration using small RNA sequencing. The stages of caudal fin regeneration were assayed for mRNA expression using mRNA sequencing. Small RNA and mRNA gene expression profiling during 0 and 4 days post amputation.
Project description:Bone is a highly regenerative tissue but it can be permanently lost due to severe trauma and as a result of disease. In zebrafish, which are capable of complex organ regeneration, intramembranous bones of the fins and skull regenerate rapidly even after profound loss. The fin regenerate, albeit being composed of different tissues is a structure of modest complexity which, together with the fact that it is easy to access and monitor, makes it a useful system to study bone formation, wound healing and metabolic disease. Glucocorticoids are powerful drugs used in anti-inflammatory and immunosuppressive therapy. Despite their unmistakable advantages and usefulness, long term treatment with glucocorticoids can cause a variety of adverse effects such as insulin resistance, high blood pressure and bone fragility. Here we made use of proteomics to study the fin regeneration by sampling zebrafish caudal fins without prior injury and regenerated tissue 4 days post amputation at normal and perturbed conditions (prednisolone-treatment).
Project description:Genome-wide microarray analysis of the effects of swim-training on caudal fin development in zebrafish larvae. Zebrafish were subjected to swim-training from 5 days post fertilization (dpf) until 10 dpf. Subsequently, we performed a genome-wide microarray analysis on the caudal fins of control and trained fish at 10 dpf. The goal of the project was to investigate the effects of swim-training on the gene expression level during caudal fin development in zebrafish larvae. Two-condition experiment: control vs trained fish. RNA was isolated from pooled caudal fins of 15 control fish (in duplo: pooled control samples (C2 and C3)) and of 15 trained fish (in duplo: pooled trained samples( T2 and T3)). Subsequently, each pooled RNA sample of control and trained caudal fins was labeled with Cy3 and Cy5 in order to correct for dye bias. We included a technical replicate of the labeled C2 and T2 samples.
Project description:Zebrafish have the remarkable ability to regenerate body parts including the heart, spinal cord and fins by a process referred to as epimorphic regeneration. Recent studies have illustrated that similar to adult zebrafish, early life stage-larvae also possess the ability to regenerate the caudal fin. A comparative genomic analysis was used to determine the degree of conservation in gene expression among the regenerating adult caudal fin, adult heart and larval fin. Results indicate that these tissues respond to amputation/injury with strikingly similar genomic responses. Comparative analysis revealed raldh2, a rate-limiting enzyme for the synthesis of Retinoic acid (RA), as one of the highly induced genes across the three regeneration platforms. Keywords: comparative genomics Overall design: The caudal fin of zebrafish larvae at 2days post fertilization were amputated. Caudal fin tissue at 2dpf and regenerating fins were isolated at 1, 2and 3 days post amputation. Three replicates were collected at each time point. 150 fins were pooled to comprise one replicate.
Project description:Fish have a high ability to regenerate fins, including the caudal fin. After caudal fin amputation, original bi-lobed morphology is reconstructed during its rapid regrowth. It is still controversial whether positional memory in the blastema cells regulates reconstruction of fin morphology as in amphibian limb regeneration, in which limb blastema cells located at the same proximal-distal level have the same positional identity. We investigated growth period and growth rate in zebrafish caudal fin regeneration. We found that both the growth period and growth rate differed for fin rays that were amputated at the same proximal-distal level, indicating that it takes different periods of time for fin rays to restore their original lengths after straight amputation. We also show that more proximal amputation takes longer period to reconstruct the original morphology/size than more distal amputation. Statistical analysis suggested that both the growth period/rate are determined by amputated length (depth) regardless of the fin ray identity along dorsal-ventral axis. In addition, we suggest the possibility that the structural/physical condition such as width of the fin ray at the amputation site (niche at the stump) may determine the growth period/rate.
Project description:We compared transcriptional profiles of regenerating zebrafish caudal fins following fin amputation with profiles from uninjured zebrafish caudal fins Overall design: Examination of whole fin transcriptional profiles from regenerating fins (2 pools of 10 fins) and uninjured fins (2 pools of 10 fins)
Project description:Olsen et al (2010) have shown that induced Diabetes mellitus (DM) in adult Zebrafish results in an impairment of tissue regeneration as monitored by caudal fin regeneration. In those studies, streptozocin was used to induce hyperglycemia in adult zebrafish, and then, following streptozocin withdrawal, a recovery phase was allowed to re-establish euglycemia, due to pancreatic b-cell regeneration. DM-associated impaired fin regeneration continued indefinitely in the metabolic memory state (MM); allowing for subsequent molecular analysis of the underlying mechanisms of MM. This study focuses on elucidating the molecular basis explaining DM-associated impaired fin regeneration and why it persists into the MM state. The analysis of microarray data indicated that of the 14,900 transcripts analyzed, aberrant expression of 71 genes relating to tissue developmental and regeneration processes were identified in DM fish and the aberrant expression of these 71 genes persisted into the MM state. Key regulatory genes of major signal transduction pathways were identified among this group of 71; and therefore, these findings provide a possible explanation for how hyperglycemia induces impaired fin regeneration and why it continues into the MM state. Total RNA was extracted from caudal fin at 0, 12, 24 and 48 hours post amputation from untreated controls and metabolic memory zebrafish.