Promoter Complexity and Tissue-Specific Expression of Stress Response Components in Mytilus galloprovincialis, a Sessile Marine Invertebrate Species

The mechanisms of stress tolerance in sessile animals, such as molluscs, can offer fundamental insights into the adaptation of organisms for a wide range of environmental challenges. One of the best studied processes at the molecular level relevant to stress tolerance is the heat shock response in the genus Mytilus. We focus on the upstream region of Mytilus galloprovincialis Hsp90 genes and their structural and functional associations, using comparative genomics and network inference. Sequence comparison of this region provides novel evidence that the transcription of Hsp90 is regulated via a dense region of transcription factor binding sites, also containing a region with similarity to the Gamera family of LINE-like repetitive sequences and a genus-specific element of unknown function. Furthermore, we infer a set of gene networks from tissue-specific expression data, and specifically extract an Hsp class-associated network, with 174 genes and 2,226 associations, exhibiting a complex pattern of expression across multiple tissue types. Our results (i) suggest that the heat shock response in the genus Mytilus is regulated by an unexpectedly complex upstream region, and (ii) provide new directions for the use of the heat shock process as a biosensor system for environmental monitoring

The Wave equation : control and numerics

International audienc

Determination of the phenolic profile of peach (Prunus persica L.) kernels using UHPLC-LTQ OrbiTrap MS/MS technique

Recently, search for new natural sources of compounds with health-enhancing properties prompted interest in fruit kernels. This paper aims to assess peach kernels as a source of nutritionally important compounds, such as phenolic compounds. A total of 25 kernels from various peach germplasm differing in origin and ripening time were characterized by their phenolic profiles. Ultra-high-Performance Liquid Chromatography coupled with Linear Trap Quadrupole and OrbiTrap MS/MS hybrid mass spectrometry was used for determination of 76 different organic compounds. The content of identified phenolic compounds indicated peach kernel as reliable source of bioactive substances with prevalent concentrations of catechin and several phenolic acids. Statistical procedures confirm that phenolic compounds could be used as phytochemical biomarkers to differentiate peach kernel samples belonging to different cultivars/genotypes according to their origin and ripening time. The CATPCA confirmed the possibility of application of chemical profiles presented only as categorical variables for classification