Project description:To understand molecular mechanisms of the joint effects of 2,4,6-trinitrotoluene (TNT) and hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX), both widely used ordnance compounds, we constructed a microarray consisting of 4,032 cDNA isolated from the earthworm Eisenia fetida using the suppressive subtractive hybridization technique. Worms were exposed to TNT-, RDX-, or TNT+RDX-spiked soil for 28 days (TNT 50 mg/kg, RDX 30 mg/kg). Keywords: Combined toxicity of TNT and RDX to earthworm (Eisenia fetida)
Project description:To understand molecular mechanisms of the chronic, sublethal toxicity of 2,4,6-trinitrotoluene (TNT), a widely used ordnance compound of public concerns, we constructed a microarray consisting of 4,032 cDNA isolated from the earthworm Eisenia fetida using the suppressive subtractive hybridization technique. Worms were exposed to a gradient of TNT-spiked soil for 28 days. Based on the reproduction response to TNT, four treatments, i.e., control, 7, 35 and 139 ppm, were selected for gene expression studies. Keywords: Sublethal toxicity of TNT (dose-response) to earthworm (Eisenia fetida)
Project description:To understand molecular mechanisms of the joint effects of 2,4,6-trinitrotoluene (TNT) and hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX), both widely used ordnance compounds, we constructed a microarray consisting of 4,032 cDNA isolated from the earthworm Eisenia fetida using the suppressive subtractive hybridization technique. Worms were exposed to TNT-, RDX-, or TNT+RDX-spiked soil for 28 days (TNT 50 mg/kg, RDX 30 mg/kg). Keywords: Combined toxicity of TNT and RDX to earthworm (Eisenia fetida) We analyzed 40 arrays for 4 treatments (control, TNT 50ppm, RDX 30ppm, TNT 50ppm + RDX 30ppm) with 5 biological replicates per treatment using an interwoven loop design.
Project description:Purpose: We studied the potential effects of lindane aging in soil on model earthworm Eisenia fetida at the transcriptomic level. Methods: transcriptomes of earthworms were generated by RNA sequencing using Illumina Hiseq Xten platform. Results: There were 1325 DE unigenes in G2 (1074 up and 251 down), 784 DE unigenes in G3 (457 up and 327 down), 3658 DE unigenes in G4 (2294 up and 1364 down), and 1511 DE unigenes in G5 (929 up and 582 down) compared with G1. Except in G2, lindane exposure caused significant impacts on cholinergic and GABAergic synaptic transmission in earthworms in other groups. The metabolic processes of ACh were also altered. It was of note that the term positive regulation of locomotion (GO:0040017) in G5 could be regarded as the phenotype of the interaction of two NTs. Conclusions: We found that aging of lindane prior to exposure promoted the disrupting effects of lindane on earthworm neurotransmission.
Project description:The earthworm Eisenia fetida is one of the most used species in standardized soil ecotoxicity tests. Endpoints such as survival, growth and reproduction are ecologically relevant but provide little mechanistic insight into the toxicity pathways, especially at the molecular level. To better understand toxicological modes of action and to facilitate the development of molecular biomarkers, we have obtained 30,245 unique EST sequences from E. fetida and have designed a novel microarray with 15,119 60-mer oligonucleotide probes. These probes target the unique non-redundant EST sequences identified in E. fetida. Using this array we have profiled gene expression of E. fetida after exposure to CL-20, a cage cyclic nitramine previously found exhibiting reversible neurotoxicity to worms. Worms were exposed for 6 days to CL-20. Half of the exposed worms were allowed to recover in a clean environment for 7 days. Electrophysiological analysis showed that the conduction velocity of worm medial giant nerve fiber was significantly decreased after 6-d exposure to CL-20, and that giant nerve fiber function was restored at the end of the 7-d recovery period. Total RNA samples isolated from four treatment groups (6 replicates per group), i.e., 6-d control, 6-d exposed, 13-d control and 6-d exposed with 7-d recovery, were analyzed using the new 15K oligo array. Bioinformatics and statistical analyses have identified specific neurological pathways affected by CL-20 and recovery of these pathways after CL-20 removal. These results provide significant insights on the CL-20 toxic mode of action and how earthworms can recover from chemical stressors.