Project description:The study aimed to characterize miRNA expression in rainbow trout ovary during ovarian development from immature to mature stages. Whole ovary were collected at the following stages: immature pre-vitelogenesis (IMM), mid-vitellogenesis (MV), late vitellogenesis (LV), post-vitellogenesis (PV) and mature while meiotic maturation is in progress (MAT). miRNA expression in rainbow trout ovary was measured at 5 different stages (immature, mid-vitellogenesis, late vitellogenesis, post-vitellogenesis and mature). Two to three biological replicates were used for each stages.
Project description:The study aimed to characterize gene expression in rainbow trout ovary during ovarian development from immature to mature stages. Whole ovary were collected at the following stages: immature pre-vitelogenesis (IMM), mid-vitellogenesis (MV), late vitellogenesis (LV), post-vitellogenesis (PV) and mature while meiotic maturation is in progress (MAT). Gene expression in rainbow trout ovary was measured at 5 different stages (immature, mid-vitellogenesis, late vitellogenesis, post-vitellogenesis and mature). Three to four biological replicates were used for each stages.
Project description:Zygotic repair of paternal genome is a key event after fertilization. Spermatozoa accumulate DNA single and double strand breaks during spermatogenesis and can suffer additional damage before fertilization by different factors, including cryopreservation. Fertilization with DNA damaged spermatozoa (DDS) is considered to promote implantation failures and abortions, but also long term effects in the progeny that could be related to a defective repair. Base excision repair (BER) pathway is considered the most active in zygotic DNA repair, but healthy oocytes contain enzymes for all repairing pathways. In this study the effects of the inhibition of the BER pathway in the zygote, were analyzed on the progeny obtained after fertilization with differentially DDS. Massive gene expression (37.394 transcripts) was analyzed after hatching using microarrays. Trout oocytes are easily fertilized with DDS and the high prolificacy allows obtaining live progeny even with a high rate of abortions. Results showed that DDS, even if increased the number of abortions, provided normal progeny. Nevertheless, the zygotic inhibition of PARP, upstream the BER pathway, result 810 differentially expressed genes (DEGs) after hatching. DEGs are related to DNA repair, apoptosis, telomere maintenance or growth and development, revealing a scenario of impaired DNA damage signalization and repair. Down-regulation of the apoptotic cascade was noticed, suggesting a selection of embryos tolerant to residual DNA damage during embryo development. Our results suggest a high zygotic capacity to repair paternal DNA damage and reveals changes in the progeny from defective repairing zygotes whose long term consequences should be deeply analyzed Gene expression was analyzed in trout larvae one day after hatching obtained from differentially DNA damaged sperm with or without zygotic inhibition of the BER pathway of DNA repair. Eggs from two females were pooled and fertilized with sperm fresh (F samples) or cryopreserved using different procedures (LDL and EY samples). Ten min later two batches from each sperm kind were treated with 3-aminobenzamide (3AB) to inhibit the PARP activity. Ten larvae per each one of the 6 treatments (3sperm kind x 2 zygotic treatments) were analyzed after pooling RNA. Four replicates per treatment were done fertilizing eggs from the same females with sperm from 4 different males.
Project description:Fish in use in aquaculture display large variation in gamete biology. To reach better understanding around this issue, this study aims at identifying if M-bM-^@M-^\egg life history traitsM-bM-^@M-^] can be hidden in egg transcriptomes. To pursue this, salmon and cod eggs were selected due to their largely differencing phenotypes (size, robustness, fresh/marine). An oligo microarray analysis was performed on ovulated eggs from cod (~23M-BM- 000 genes, n=8) and salmon (~44M-BM- 000 genes, n=7). The arrays were normalized to a similar spectrum for both arrays. Both arrays were re-annotated based on official gene symbol to retrieve an orthologous KEGG annotation, in salmon and cod arrays this represented 14009 and 7437 genes respectively. The probe linked to the highest gene expression for that particular KEGG annotation was used to compare expression between species. Differential expression was calculated for genes that had an annotation with score > 300, resulting in a total of 2354 KEGG annotations (genes) being differently expressed between the species. The most differentially expressed genes in salmon and cod (FDM-bM-^IM-%2), were used to reveal pathways that were overrepresented in the eggs of each species. This analysis revealed that immune, signal transduction, and excretory related pathways were overrepresented in salmon compared to cod. The most overrepresented pathways in cod were related to regulation of genetic information processing and metabolism. To conclude this analysis clearly point at some distinct transcriptome repertoires for cod and salmon and that these differences may explain some of the species-specific biological features for salmon and cod eggs. 16 samples
Project description:Sleep has been strongly implicated in learning and especially in the reprocessing of recently acquired memory. Children with intellectual disability (ID) tend to have sleep-wake disturbances, which may contribute to the pathophysiology of the disease. As far as sleep is, in part, a circadian process, we decided to study rhythmic gene expression in hippocampus, a brain structure, which plays a key role in memory in human and rodents. By investigating the transcriptome of mouse adult hippocampus, we report here the identification of 663 circadian rhythm (CR)-regulated genes, which have been clustered in four categories, based on their temporal pattern of expression. In addition to the standard core-clock genes, enrichment analysis of the hippocampal CR-regulated genes revealed the presence of several transcription factors, underlying the existence of an inter-regulation of genes' expression between clusters. Interestingly, these hippocampal circadian rhythm-regulated genes are very enriched in sleep/wakefulness related genes. We show here that glucocorticoid signaling, already shown to be involved in memory regulation, is a circadian regulated pathway in hippocampus. Furthermore, we identified a list of 30 CR-regulated ID genes. Our results demonstrate that hippocampus can be considered as a peripheral oscillator and illustrate the link between circadian rhythm, sleep, intellectual disability and memory consolidation. In order to identify circadian rhythm-regulated genes in mouse hippocampus, we realized a study in dark-dark conditions, thus allowing to overcome the effects induced by light changes. To systematically identify genes with circadian regulated expression, RNA samples from the hippocampus of three mice at four Circadian Time (CT) points were used for expression profiling using Agilent microarray technology. The dark/dark period started at 7 p.m. The Circadian Time (CT) 18 samples were taken after 30 h of continuous dark; the other circadian times followed at 6-h intervals: CT0, CT6 and CT12 after 36, 42 and 48 h of continuous darkness, respectively.
Project description:To further develop gene expression approach to miRNA biomarker discovery, we have employed miRNA microarray expression profiling as a discovery platform to identify miRNA with the potential to regulated the gene expression signatures in the process of tumor development. Human FFPE tissues from grade 1, 2 and 3 were used to profile miRNA. The miRNA targeted genes were also studied for expression along with the selected miRNA, from this signature in the same RNA samples by real-time PCR, confirming the selected miRNA has regulatory action on the target gene expression. miRNA were profiled with less number of samples from each grade using miRNa microarray hybridization. Confirmation of the expression was carried out with more (20 from each grade)number of samples and targetted gene expression regulation was confirmed using RT PCR.
Project description:Free-range chickens were sampled from homesteads in South Africa where DDT is sprayed for malaria control. The purpose was to detect potential effects associated with contamination. Livers were sampled post-mortem & analysed for DDTs (DDT and metabolites) contamination. Samples from two birds were further processed by microarray analysis – one with a relatively low (1,116.0 ng/g wet weight; sample SA1) and one with a relatively high (1,938.0 ng/g wet weight; sample SA2) level of contamination by DDTs.
Project description:Molecular basis of transition to addiction in vulnerable individuals is largely unknown. We hypothesized that human susceptibility genes can be identified on the basis of conserved molecular mechanisms in rodent brains. We used a short-term cocaine-dependent conditioned place preference (CPP) to identify genetic hallmarks of early steps of reward memory in basal ganglia including accumbens nucleus (NAc), globus pallidus (GP) and subthalamic nucleus (STN). Using genome-wide microarray analysis and CPP as a quantitative trait, we found that synaptic plasticity-related genes are deregulated in these three structures. A significant enrichment in bona fide transcripts involved in dendritic spine local translation was evidenced. mGluR5 is transcriptionally deregulated in Acc and GP of cocaine-treated animals. Grin3a that encodes a NMDA receptor subunit involved in Ca++ permeability is deregulated in NAc. Furthermore, Orexin/Hcrt transcript level is decreased in STN, a region known to be involved in discriminating addictive drugs and natural rewards. We also found that mGluR5 and Grin3a expression deregulation is sufficient to induce changes in synaptic plasticity-related genes. Altogether, these results suggest that a combined deregulation of mGluR5 and Grin3A pathway in NAc, mGluR5 in GP and orexin system in STN may generate an incentive memory contrasted between addictive drugs and natural rewards. Such pathways may include clusters of genes that are potential susceptibility genes for transition to addiction. Agilent Whole Mouse Genome oligomicroarrays (GEO accession no. GPL2872, Agilent Technologies, Palo Alto, CA) were used. They contain 60-mer DNA probes synthesized in situ in a 44k format. Of 44,290 spots, 2756 are controls. The remaining 41,534 spots represent 33,661 unique transcripts which correspond to 20,202 unique human genes. Five independent (four accumbens nuclei from mice treated with cocaine compared to four accumbens nuclei from mice treated with saline solution) measurements were carried out for each group of biological conditions using exchanged dye-labeled RNA targets (i.e., Cy3 and Cy5 dyeswapping experiments). Each hybridization was numerized hybridization by a GenePix 4000B Microarray Scanner and an Agilent G6525 Microarray Scanner.
Project description:The aim of this study was to measure chronic sublethal effects of the flame retardant Tris(2-butoxyethyl)phosphate (TBEP) on gene expression, associated protein activity and life-history endpoints (reproduction, development) in the freshwater crustacean Daphnia magna. We exposed <24h old D. magna neonates for 21 days to culture medium (control) and to 3 sublethal doses of TBEP: 14.7, 147 and 1470 M-BM-5g/L. Exposure doses were chosen from 48h acute toxicity testing and represent 1/10000, 1/1000 and 1/100 of the LC50, respectively. Each condition (control and the 3 different doses) were performed on 3 independant biological replicates, with 10 individuals each. We used a custom 15000 sequences D. magna microarray to measure transcriptional effect of each of the TBEP doses in comparison to unexposed controls. We exposed <24h old Daphnia magna to culture medium (unexposed controls) and 3 sublethal doses of TBEP (14.7M-BM-5g/L, 147M-BM-5g/L and 1470M-BM-5g/L) for 21 days. We used 3 biological replicates of 10 individuals for each condition.
Project description:MicroRNAs regulate various cellular processes. While several genes associated with replicative senescence have been described in endothelial cells, miRNAs that regulate these genes remain largely unknown. The present study was designed to identify miRNAs associated with replicative senescence and their target genes in HUVECs. We have employed Agilent Human MicroRNAs microarray platform to evaluate the expressions of 866 human miRNAs and 89 human viral miRNAs, based on Sanger miRNA database release 12.0 miRNA expression profiles were established for young and replicative senescent HUVECs