From cells to recapture rates: responses and recovery of a wild fish after an experimental exposure to a widely used herbicide.

Freshwater environments are biodiversity hotspots under multiple pressures, including pesticide exposure. S-metolachlor, a widely used herbicide, can induce genotoxic, cytotoxic and physiological effects in captive fish, but we have a limited understanding of the effects of exposure to S-metolachlor in free-living vertebrates. We carried out an original field experiment using integrative approaches across biological levels and temporal scales.

Xenopus as a model to study alternative splicing in vivo.

An increasing number of genes are being identified for which the corresponding mRNAs contain different combinations of the encoded exons. This highly regulated exon choice, or alternative splicing, is often tissue-specific and potentially could differentially affect cellular functions. Alternative splicing is therefore not only a means to increase the coding capacity of the genome, but also to regulate gene expression during differentiation or development.

Oligomerization of EDEN-BP is required for specific mRNA deadenylation and binding.

Background Information: mRNA deadenylation [shortening of the poly(A) tail] is often triggered by specific sequence elements present within mRNA 3' untranslated regions and generally causes rapid degradation of the mRNA. In vertebrates, many of these deadenylation elements are called AREs (AU-rich elements). The EDEN (embryo deadenylation element) sequence is a Xenopus class III ARE.

PTB regulates the processing of a 3'-terminal exon by repressing both splicing and polyadenylation.

The polypyrimidine tract binding protein (PTB) has been described as a global repressor of regulated exons. To investigate PTB functions in a physiological context, we used a combination of morpholino-mediated knockdown and transgenic overexpression strategies in Xenopus laevis embryos. We show that embryonic endoderm and skin deficient in PTB displayed a switch of the alpha-tropomyosin pre-mRNA 3' end processing to the somite-specific pattern that results from the utilization of an upstream 3'-terminal exon designed exon 9A9'.

Reconstruction of cluster distributions at 100% detection efficiency for a track-nanodosimetric counter through a Bayesian analysis.

A Bayesian unfolding has been applied to ionisation distributions due to 5.4 MeV alpha particles in a 20-nm site obtained using Monte Carlo simulations, taking into account different detection efficiency conditions. The ideal case of a target volume with uniform efficiency has been investigated to study the dependence of the reconstruction on prior distributions.