title: Promoter complexity and tissue-specific expression of stress response components in Mytilus galloprovincialis, a sessile marine invertebrate species.
abstract: 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.
authors.affiliation: Department of Genetics, Development & Molecular Biology, School of Biology, Faculty of Sciences, Aristotle University of Thessaloniki, Thessaloniki, Greece.
authors.forename: Chrysa
authors.initials: C
authors.lastname: Pantzartzi
authors.forename: Elena
authors.initials: E
authors.lastname: Drosopoulou
authors.forename: Minas
authors.initials: M
authors.lastname: Yiangou
authors.forename: Ignat
authors.initials: I
authors.lastname: Drozdov
authors.forename: Sophia
authors.initials: S
authors.lastname: Tsoka
authors.forename: Christos A
authors.initials: CA
authors.lastname: Ouzounis
authors.forename: Zacharias G
authors.initials: ZG
authors.lastname: Scouras
mesh_terms: D000704:Analysis of Variance; D000818:Animals; D001483:Base Sequence; D016000:Cluster Analysis; D017124:Conserved Sequence; D020869:Gene Expression Profiling; D018841:HSP90 Heat-Shock Proteins / Q000235:genetics / Q000378:metabolism; D020084:Long Interspersed Nucleotide Elements / Q000235:genetics; D008957:Models, Genetic; D015233:Models, Statistical; D008969:Molecular Sequence Data; D049878:Mytilus / Q000235:genetics*; D009369:Neoplasms / Q000235:genetics; D009928:Organ Specificity; D025341:Principal Component Analysis; D011401:Promoter Regions, Genetic; D016415:Sequence Alignment; D013312:Stress, Physiological / Q000235:genetics*; D016159:Tumor Suppressor Protein p53 / Q000235:genetics / Q000378:metabolism
chemical_list: D018841:HSP90 Heat-Shock Proteins; D016159:Tumor Suppressor Protein p53