Project description:Caenorhabditis elegans, a free-living nematode, were exposed to sulfomethaxozale (SMX) for 11 consecutive generations. The F11 nematodes and their first non-exposed progeny (F14’) went through chromatin immune-precipitation at H3K4me3 site and a subsequent DNA-sequencing. Results showed that F11 and F14’ nematodes had 3-fold more H3K4me3 biding genes than the control. These genes showed the highest enrichment in the promoter region with 42.11% and 73.72% in F11 and F14’ nematodes, respectively, indicating increased activity of their regulated genes. In F11 nematodes, the genes regulating metabolic and biosynthetic processes of phospholipid, glycerolipid and glycerophospholipid were significantly activated with a mean enrichment fold change of 50.57. The genes regulating nervous system and development were also activated with a mean enrichment fold change of 65.03 and 58.14, respectively. In F14’ nematodes, 96 and 67 genes showed up- and down-regulations compared with those in F11 nematodes. In the up-regulation, genes regulating development, reproduction and transmembrane transport showed mean enrichment fold changes of 2.52, 22.41 and 34.47, respectively. The down-regulated genes were also related with development, reproduction and transmembrane activities with mean enrichment fold changes ranging from 1.51 to 8.32. Our findings demonstrated the epigenetic involvement in the SMX trans-generational effects.
Project description:Bio-electrospray, the direct jet-based cell handling apporach, is able to handle a wide range of cells. Studies at the genomic, genetic, and the physiological level have shown that, post-treatment, cellular integrity is unperturbed and a high percentage (>70%, compared to control) of cells remain viable. Although, these results are impressive, it may be argued that cell based systems are oversimplistic. This study utilizing a well characterised multicellular model organism, the non-parasitic nematode Caenorhabditis elegans. Nematodes were subjected to bio-electrosprays to demonstrate that bio-electrosprays can be safely applied to nematodes.
Project description:In the current study a systematic investigation of life stage, tissue and cell dependent sensitivity to ionizing radiation in the nematode Caenorhabditis elegans was conducted. This revealed that individuals that have reached the post-mitotic L4 stage showed no significant effects with respect to mortality, morbidity or reproduction when subjected to either acute dose ≤6 Gy(1500 mGy/h) or chronic exposure ≤4 Gy( ≤ 100 mGy/h). In contrast, chronic exposure from embryo to young adult stage caused a dose and dose rate dependent reprotoxicitiy with 43% reduction in total brood size at 6.7Gy (107 mGy/h). Systematic targeted irradiation of developmental stages showed that exposure during L1 to young L4 was sufficient to induce reprotoxic effects. Exposure during these stages was associated with a dose rate dependent genotoxic effects on gonads with 1.7 to 3.2 fold increase in germ cell apoptosis in larvae subjected to 40-100 mGy/h, respectively. Importantly, exposure to gamma radiation significantly impaired spermatogenesis in a dose rate dependent manner. The observed reduction in the number of spermatids accounted for xx% of the reprotoxic effects, thus signifying spermatids as the most radiosensitive cell type in C. elegans. Molecular responses analyzed by RNAseq of nematodes irradiated from L1 to L4 stage revealed a significant enrichment of genes related to both male and hermaphrodite reproductive processes. Gene network analysis identified adverse genotoxic effects related to down-regulation of genes required for spindle formation and sperm meiosis/maturation, including smz-1, smz-2 and htas-1. The expression of a subset of 28 set-17 regulated Major Sperm Proteins (MSP) required for spermatids production was correlated to the reduction in reproduction and the number of spermatids, thus corroborating the impairment of spermatogenesis as the major cause of gamma radiation induced life-stage dependent reprotoxic effect. Furthermore, the progeny of irradiated nematodes showed significant embryonal DNA damage that was associated with persistent effect on somatic growth. Unexpectedly, these nematodes did however maintain much of their reproductive capacity in spite of the reduced growth.
Project description:We assessed the whole genome response of C. elegans exposed for 48 hours from L1 to the pristine silver nanomterials, artifically aged silver nanomatierls, and AgNO3. Single time point RNA extraction from a population of 2000-3000 nematodes exposed to the EC30 for reproduction.
Project description:We have previously reported that tyrosol (TYR), one of the main phenols in extra virgin olive oil (EVOO), promotes lifespan extension in the nematode Caenorhabditis elegans, also inducing a stronger resistance to thermal and oxidative stress in this animal model. Although the influence of several longevity-related genes in these effects has been reported by our group, we decided to perform a whole genome DNA-microarray approach in order to identify other genes and molecular pathways further involved in TYR effects on C. elegans longevity. Microarray analysis identified 208 differentially expressed genes (206 overexpressed and 2 underexpressed) when comparing TYR-treated nematodes with non-treated controls. Many of these genes seem linked to processes such as regulation of growth, transcription, reproduction, lipid metabolism and body morphogenesis. Data obtained by microarray was validated by qRT-PCR analysis of selected genes. Our results confirm that several important cellular mechanisms related to longevity are influenced by TYR treatment in this animal model. Moreover, we detected an interesting overlap between the expression pattern elicited by TYR and those induced by other dietary polyphenols known to extend lifespan in C. elegans, such as quercetin and tannic acid.
Project description:Comparison of miRNA profiles of wildtype and lin-28(n719); lin-46(ma164) Caenorhabditis elegans nematodes at the L1 stage Two genotypes, wildtype vs. mutant. Biological replicates: 3 wild type, 3 mutant, independently grown and harvested. One replicate per slide.
Project description:This project defines the transcriptomes of XO (male) and XX (female or mutant pseudo-female) Caenorhabditis nematodes. The data allow the overall composition and sexual regulation of the transcriptome within a single species to be determined. In addition, the five related species studied allow meta-comparisons between them. Because two of the five (C. elegans and C. briggsae) produce a self-fertile XX hermaphrodite, while the XX sex in the remaining three (C. japonica, C. remanei, and C. brenneri) are true females, the data are particularly useful for inferring effects of sexual mode on genome-wide gene expression.
Project description:The nematode Caenorhabditis elegans contains each of the broad classes of eukaryotic small RNAs, including microRNAs (miRNAs), endogenous small-interfering RNAs (endo-siRNAs) and piwi-interacting RNAs (piRNAs). To better understand the evolution of these regulatory RNAs, we deep sequenced small RNAs from C. elegans and three closely related nematodes: C. briggsae, C. remanei and C. brenneri. The results reveal a fluid landscape of small RNA pathways with essentially no conservation of individual sequences aside from a subset of miRNAs. We identified 52 miRNA families that are conserved in each of the four species as well as numerous miRNAs that are species specific or shared between only two or three species. Despite a lack of conservation of individual piRNAs and siRNAs many of the features of each pathway, including genomic distribution, are conserved. We show that in each species, 26G siRNAs trigger stage-specific secondary siRNA formation. We also observe that piRNAs trigger siRNA formation from targets containing up to three mismatches in each species. Finally, we show that nematodes produce two distinct sex-specific classes of piRNAs, suggesting different roles for piRNAs in male and female germlines. Sequencing small RNAs from four Caenorhabditis species: C. elegans, C. briggsae, C. remanei and C. brenneri