De novo transcriptome assembly, functional annotation and differential gene expression analysis of juvenile and adult E. fetida, a model oligochaete used in ecotoxicological studies

BACKGROUND: Earthworms are sensitive to toxic chemicals present in the soil and so are useful indicator organisms for soil health. Eisenia fetida are commonly used in ecotoxicological studies; therefore the assembly of a baseline transcriptome is important for subsequent analyses exploring the impact of toxin exposure on genome wide gene expression. RESULTS: This paper reports on the de novo transcriptome assembly of E. fetida using Trinity, a freely available software tool. Trinotate was used to carry out functional annotation of the Trinity generated transcriptome file and the transdecoder generated peptide sequence file along with BLASTX, BLASTP and HMMER searches and were loaded into a Sqlite3 database. To identify differentially expressed transcripts; each of the original sequence files were aligned to the de novo assembled transcriptome using Bowtie and then RSEM was used to estimate expression values based on the alignment. EdgeR was used to calculate differential expression between the two conditions, with an FDR corrected P value cut off of 0.001, this returned six significantly differentially expressed genes. Initial BLASTX hits of these putative genes included hits with annelid ferritin and lysozyme proteins, as well as fungal NADH cytochrome b5 reductase and senescence associated proteins. At a cut off of P = 0.01 there were a further 26 differentially expressed genes. CONCLUSION: These data have been made publicly available, and to our knowledge represent the most comprehensive available transcriptome for E. fetida assembled from RNA sequencing data. This provides important groundwork for subsequent ecotoxicogenomic studies exploring the impact of the environment on global gene expression in E. fetida and other earthworm species.

Etanol e isopropanol: genotoxicidad y teratogénesis evaluada aplicando el modelo de Drosophila melanogaster / Ethanol and isopropanol: genotoxicity and teratogenicity evaluated using Drosophila melanogaster as a model system

El etanol y el isopropanol son, de los alcoholes alifáticos de cadena corta, los más frecuentemente asociados a la actividad humana tanto a nivel industrial como en el entorno doméstico. En este trabajo se presentan los principales hallazgos reportados en la literatura para ensayos de genotoxicidad y teratogénesis en modelos experimentales de distinto nivel de complejidad, con especial énfasis en Drosophila melanogaster. El metabolismo de estos alcoholes es semejante en Drosophila y en humanos por lo cual la mosca es un buen modelo in vivo para la evaluación de sus potenciales efectos tóxicos, genotóxicos y teratogénicos.

Ethanol and isopropanol are two of the short chain aliphatic alcohols more frequently associated to the human environment, both in the industrial and domestic conditions. The aim of this work was to present the main findings reported in the literature about their genotoxicity and teratogenicity in experimental models of different level of complexity, with special emphasis in Drosophila melanogaster. Taking into account that the metabolism of both alcohols in Drosophila and humans is similar, the fly is a good model for the evaluation of their potentially toxic, genotoxic and teratogenic effects.