A semi-automated high-throughput approach to the generation of transposon insertion mutants in the nematode Caenorhabditis elegans

The generation of a large collection of defined transposon insertion mutants is of general interest to the Caenorhabditis elegans research community and has been supported by the European Union. We describe here a semi-automated high-throughput method for mutant production and screening, using the heterologous transposon Mos1. The procedure allows routine culture of several thousand independent nematode strains in parallel for multiple generations before stereotyped molecular analyses. Using this method, we have already generated >17 500 individual strains carrying Mos1 insertions. It could be easily adapted to forward and reverse genetic screens and may influence researchers faced with making a choice of model organism

A Genome-Wide Collection of Mos1 Transposon Insertion Mutants for the C. elegans Research Community

Methods that use homologous recombination to engineer the genome of C. elegans commonly use strains carrying specific insertions of the heterologous transposon Mos1. A large collection of known Mos1 insertion alleles would therefore be of general interest to the C. elegans research community. We describe here the optimization of a semi-automated methodology for the construction of a substantial collection of Mos1 insertion mutant strains. At peak production, more than 5,000 strains were generated per month. These strains were then subject to molecular analysis, and more than 13,300 Mos1 insertions characterized. In addition to targeting directly more than 4,700 genes, these alleles represent the potential starting point for the engineered deletion of essentially all C. elegans genes and the modification of more than 40% of them. This collection of mutants, generated under the auspices of the European NEMAGENETAG consortium, is publicly available and represents an important research resource

Dose-effect study of Gelsemium sempervirens in high dilutions on anxiety-related responses in mice

Introduction This study was designed to investigate the putative anxiolytic-like activity of ultra-low doses of Gelsemium sempervirens (G. sempervirens), produced according to the homeopathic pharmacopeia. Methods Five different centesimal (C) dilutions of G. sempervirens (4C, 5C, 7C, 9C and 30C), the drug buspirone (5 mg/kg) and solvent vehicle were delivered intraperitoneally to groups of ICR-CD1 mice over a period of 9 days. The behavioral effects were assessed in the open-field (OF) and light\u2013dark (LD) tests in blind and randomized fashion. Results Most G. sempervirens dilutions did not affect the total distance traveled in the OF (only the 5C had an almost significant stimulatory effect on this parameter), indicating that the medicine caused no sedation effects or unspecific changes in locomotor activity. In the same test, buspirone induced a slight but statistically significant decrease in locomotion. G. sempervirens showed little stimulatory activity on the time spent and distance traveled in the central zone of the OF, but this effect was not statistically significant. In the LD test, G. sempervirens increased the % time spent in the light compartment, an indicator of anxiolytic-like activity, with a statistically significant effect using the 5C, 9C and 30C dilutions. These effects were comparable to those of buspirone. The number of transitions between the compartments of the LD test markedly increased with G. sempervirens 5C, 9C and 30C dilutions. Conclusion The overall pattern of results provides evidence that G. sempervirens acts on the emotional reactivity of mice, and that its anxiolytic-like effects are apparent, with a non-linear relationship, even at high dilutions

Transcript map of the human chromosome Xq11-Xq21 region: localization of 33 novel genes and one pseudogene.

International audienceThe human Xq11-Xq21.3 region has been implicated in several inherited disorders including dystonia-parkinsonism (DYT3), sideroblastic anemia and several specific and non-specific forms of mental retardation (MR) syndromes. As part of a positional cloning effort to identify MR genes, we have generated a YAC-based transcript map. We first constructed a YAC/STS framework by extending previously published contigs. This framework map consists of a minimal set of 119 clones, covering approximately 20 Megabases (Mb) and allowing the precise ordering of 71 STSs between DXS136 and DXS472. This YAC contig was then used to define the positions of genes and expressed sequence tags (ESTs) assigned to the Xcen-Xq21.3 region. In addition to the genes previously localized to this part of the X chromosome, 18 transcription units corresponding to additional known genes or gene family members, one pseudogene and 15 novel transcripts were mapped. This transcriptional map incorporates 51 transcription units and provides a useful resource of candidate genes for some of the disorders assigned to this region of the X chromosome