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Two distinct gene-silencing phenomena are observed in plants: transcriptional gene silencing (TGS), which involves decreased RNA synthesis because of promoter methylation, and posttranscriptional gene silencing (PTGS), which involves sequence-specific RNA degradation. PTGS is induced by deliberate [1-4] or fortuitous production (R.v.B., unpublished data) of(More)
Field-selected metal tolerance in Orchesella cincta is correlated with overexpression of the single copy cadmium (Cd) inducible metallothionein (mt). Previously, we have demonstrated large phenotypic variation in mt gene expression, and a higher frequency of high-expression phenotypes in a tolerant population. Here, we describe midparent-offspring(More)
Environmental pollution is a worldwide problem, and metals are the largest group of contaminants in soil. Microarray toxicogenomic studies with ecologically relevant organisms, such as springtails, supplement traditional ecotoxicological research but are presently rather descriptive. Classifier analysis, a more analytical application of the microarray(More)
Enchytraeids are ecologically relevant soil organisms, due to their activity in decomposition and bioturbation in many soil types worldwide. The enchytraeid reproduction test (ERT) guidelines ISO 16387 and OECD 220 are exclusive to the genus Enchytraeus and recommend using the species E. albidus with a 6-week test period. The suggested alternative, E.(More)
BACKGROUND Collembola (springtails) represent a soil-living lineage of hexapods in between insects and crustaceans. Consequently, their genomes may hold key information on the early processes leading to evolution of Hexapoda from a crustacean ancestor. METHOD We assembled and annotated transcriptomes of the Collembola Folsomia candida and Orchesella(More)
The cre recombinase gene was stably introduced and expressed in tomato, petunia and Nicotiana tabacum. Some plants expressing the cre gene driven by a CaMV 35S promoter displayed growth retardation and a distinct pattern of chlorosis in their leaves. Although no direct relation can be proven between the phenotype and cre expression, aberrant phenotypes(More)
BACKGROUND In recent years, several new hypotheses on phylogenetic relations among arthropods have been proposed on the basis of DNA sequences. One of the challenged hypotheses is the monophyly of hexapods. This discussion originated from analyses based on mitochondrial DNA datasets that, due to an unusual positioning of Collembola, suggested that the(More)
Metal contamination in soil ecosystems is a permanent and often strong selection pressure. The present study investigates metal tolerance in 17 Orchesella cincta (Collembola) populations from metal-contaminated and reference sites, and combines analyses at the phenotypic and molecular level. Metal tolerance was phenotypically assayed by measuring survival(More)
Field-selected tolerance to heavy metals has been reported for Orchesella cincta (Arthropoda: Collembola, springtails) populations occurring at metal-contaminated mining sites. Metal tolerance in O. cincta is correlated with heritable increase of excretion efficiency, decrease in cadmium-induced growth reduction, and over-expression of the single copy(More)
BACKGROUND Genomic studies measuring transcriptional responses to changing environments and stress currently make their way into the field of evolutionary ecology and ecotoxicology. To investigate a small to medium number of genes or to confirm large scale microarray studies, Quantitative Reverse Transcriptase PCR (QRT-PCR) can achieve high accuracy of(More)