CanVaS: Documenting the genetic variation spectrum of Greek cancer patients.

National genetic variation registries vastly increase the level of detail for the relevant population, while directly affecting patient management. Herein, we report CanVaS, a Cancer Variation reSource aiming to document the genetic variation of cancer patients in Greece. CanVaS comprises germline genetic data from 7,363 Greek individuals with a personal and/or family history of malignancy. The data set incorporates approximately 24,000 functionally annotated rare variants in 97 established or suspected cancer susceptibility genes. For each variant, allele frequency for the Greek population, interpretation for clinical significance, anonymized family and segregation information, as well as phenotypic traits of the carriers, are included. Moreover, information on the geographic distribution of the variants across the country is provided, enabling the study of Greek population isolates. Direct comparisons between Greek (sub)populations with relevant genetic resources are supported, allowing fine-grain localized adjustment of guidelines and clinical decision-making. Most importantly, anonymized data are available for download, while the Leiden Open Variation Database schema is adopted, enabling integration/interconnection with central resources. CanVaS could become a stepping-stone for a countrywide effort to characterize the cancer genetic variation landscape, concurrently supporting national and international cancer research. The database can be accessed at: http://ithaka.rrp.demokritos.gr/CanVaS.

Brain Radiation Information Data Exchange (BRIDE): integration of experimental data from low-dose ionising radiation research for pathway discovery.

BACKGROUND: The underlying molecular processes representing stress responses to low-dose ionising radiation (LDIR) in mammals are just beginning to be understood. In particular, LDIR effects on the brain and their possible association with neurodegenerative disease are currently being explored using omics technologies. RESULTS: We describe a light-weight approach for the storage, analysis and distribution of relevant LDIR omics datasets. The data integration platform, called BRIDE, contains information from the literature as well as experimental information from transcriptomics and proteomics studies. It deploys a hybrid, distributed solution using both local storage and cloud technology. CONCLUSIONS: BRIDE can act as a knowledge broker for LDIR researchers, to facilitate molecular research on the systems biology of LDIR response in mammals. Its flexible design can capture a range of experimental information for genomics, epigenomics, transcriptomics, and proteomics. The data collection is available at: .

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 Coming of Age for Big Data in Systems Radiobiology, an Engineering Perspective.

As high-throughput approaches in biological and biomedical research are transforming the life sciences into information-driven disciplines, modern analytics platforms for big data have started to address the needs for efficient and systematic data analysis and interpretation. We observe that radiobiology is following this general trend, with -omics information providing unparalleled depth into the biomolecular mechanisms of radiation response-defined as systems radiobiology. We outline the design of computational frameworks and discuss the analysis of big data in low-dose ionizing radiation (LDIR) responses of the mammalian brain. Following successful examples and best practices of approaches for the analysis of big data in life sciences and health care, we present the needs and requirements for radiation research. Our goal is to raise awareness for the radiobiology community about the new technological possibilities that can capture complex information and execute data analytics on a large scale. The production of large data sets from genome-wide experiments (quantity) and the complexity of radiation research with multidimensional experimental designs (quality) will necessitate the adoption of latest information technologies. The main objective was to translate research results into applied clinical and epidemiological practice and understand the responses of biological tissues to LDIR to define new radiation protection policies. We envisage a future where multidisciplinary teams include data scientists, artificial intelligence experts, DevOps engineers, and of course radiation experts to fulfill the augmented needs of the radiobiology community, accelerate research, and devise new strategies.

A Time-Calibrated Mitogenome Phylogeny of Catfish (Teleostei: Siluriformes).

A very significant part of the world's freshwater ichthyofauna is represented by ancient, exceptionally diverse and cosmopolitan ray-finned teleosts of the order Siluriformes. Over the years, catfish have been established as an exemplary model for probing historical biogeography at various scales. Yet, several tantalizing gaps still exist in their phylogenetic history, timeline and mode of diversification. Here, we re-examine the phylogeny of catfish by assembling and analyzing almost all publicly available mitogenome data. We constructed an ingroup matrix of 62 full-length mitogenome sequences from 20 catfish families together with four cypriniform outgroups, spanning 15,557 positions in total. Partitioned maximum likelihood analyses and Bayesian relaxed clock dating using fossil age constraints provide some useful and novel insights into the evolutionary history of this group. Loricarioidei are recovered as the first siluriform group to diversify, rendering Neotropics the cradle of the order. The next deepest clade is the South American Diplomystoidei placed as a sister group to all the remaining Siluroidei. The two multifamilial clades of "Big Asia" and "Big Africa" are also recovered, albeit nodal support for the latter is poor. Within "Big Asia", Bagridae are clearly polyphyletic. Other interfamilial relationships, including Clariidae + Heteropneustidae, Doradidae + Auchenipteridae and Ictaluridae + Cranoglanididae are robustly resolved. Our chronogram shows that siluriforms have a Pangaean origin, at least as far back as the Early Cretaceous. The inferred timeline of the basal splits corroborates the "Out-of-South America" hypothesis and accords well with the fossil record. The divergence of Siluroidei most likely postdated the final separation of Africa and South America. An appealing case of phylogenetic affinity elaborated by biogeographic dispersal is exemplified by the Early Paleogene split between the Southeast Asian Cranoglanididae and Ictaluridae, with the latter radiating into North America's freshwater realm by Eocene. The end of Cretaceous probably concludes the major bout of diversification at the family level while with the dawn of the Cenozoic a prolific radiation is evident at the generic level.

Analysis and characterization of the transcriptional unit of a new Mytilus galloprovincialis (Mollusca: Bivalvia) hsp70 gene.

We isolated, analysed and characterized the transcriptional unit of an hsp70 gene of Mytilus galloprovincialis (Mollusca: Bivalvia). Sequence analysis of a total of 3653 bp, revealed a 1914 bp ORF encoding for a 637-amino acid polypeptide that exhibits all the characteristic signatures of the cytoplasmic members of the HSP70 family. The ORF is not interrupted by introns and its 5'-flanking region contains five putative heat shock elements (HSEs), both indicating for an inducible hsp70 gene. Furthermore, nucleotide and amino acid sequence alignments with HSP70 genes from several molluscan and non-molluscan species confirmed that the newly isolated gene, the first complete in the genus Mytilus and in the Mollusca phylum, is a cytoplasmic and inducible hsp70 gene.

Functional genomics evidence unearths new moonlighting roles of outer ring coat nucleoporins.

There is growing evidence for the involvement of Y-complex nucleoporins (Y-Nups) in cellular processes beyond the inner core of nuclear pores of eukaryotes. To comprehensively assess the range of possible functions of Y-Nups, we delimit their structural and functional properties by high-specificity sequence profiles and tissue-specific expression patterns. Our analysis establishes the presence of Y-Nups across eukaryotes with novel composite domain architectures, supporting new moonlighting functions in DNA repair, RNA processing, signaling and mitotic control. Y-Nups associated with a select subset of the discovered domains are found to be under tight coordinated regulation across diverse human and mouse cell types and tissues, strongly implying that they function in conjunction with the nuclear pore. Collectively, our results unearth an expanded network of Y-Nup interactions, thus supporting the emerging view of the Y-complex as a dynamic protein assembly with diverse functional roles in the cell.

Assessment and reconstruction of novel HSP90 genes: duplications, gains and losses in fungal and animal lineages.

Hsp90s, members of the Heat Shock Protein class, protect the structure and function of proteins and play a significant task in cellular homeostasis and signal transduction. In order to determine the number of hsp90 gene copies and encoded proteins in fungal and animal lineages and through that key duplication events that this family has undergone, we collected and evaluated Hsp90 protein sequences and corresponding Expressed Sequence Tags and analyzed available genomes from various taxa. We provide evidence for duplication events affecting either single species or wider taxonomic groups. With regard to Fungi, duplicated genes have been detected in several lineages. In invertebrates, we demonstrate key duplication events in certain clades of Arthropoda and Mollusca, and a possible gene loss event in a hymenopteran family. Finally, we infer that the duplication event responsible for the two (a and b) isoforms in vertebrates occurred probably shortly after the split of Hyperoartia and Gnathostomata.

The complete mitochondrial genome of the loggerhead turtle Caretta caretta (Testudines: Cheloniidae): genome description and phylogenetic considerations.

The marine turtle Caretta caretta is a widely distributed species that is facing critical population decline, especially in the Mediterranean rookeries. Molecular markers, such as mitochondrial DNA (mtDNA) sequences, are of great importance for the description and monitoring of turtle migratory populations. The complete sequence of the C. caretta mitochondrial genome is presented here. The genome comprises 16,440 base pairs, containing 37 genes (13 protein-coding genes, 22 tRNA genes, and 2 rRNA genes), and a control region, all organized similar to the majority of vertebrate mitogenomes. MtDNA length polymorphism and heteroplasmy were observed among, and within, individuals due to the variable size of a microsatellite repeat residing at the 3' end of the control region. The use of the above repeat as a marker for individual fingerprinting is discussed. Furthermore, phylogenetic analyses among Testudines based on complete mitogenomes, as well as among marine turtles based on partial mtDNA sequences, are considered.

Genotype and allele frequencies of heme oxygenase-1 promoter region in a Greek cohort.

BACKGROUND: Heme oxygenase-1 (HO-1) is an enzyme, which catabolizes heme into carbon monoxide, biliverdin and free iron. The induction of this enzyme is an important cytoprotective mechanism, which occurs as an adaptive and beneficial response to a wide variety of oxidant stimuli. HO-1 inducibility is mainly modulated by a (GT)(n) polymorphism in the promoter region, and has been shown that short (S) repeats are associated with greater up-regulation of HO-1, compared with long (L) repeats. METHODS: In the present study, 250 healthy Greek individuals have been screened in order to estimate the frequencies of (GT)(n) alleles in the HO-1 gene. RESULTS: Nineteen different alleles, ranging from 17 to 39 repeats, with (GT)(23) and (GT)(30) being the most common ones, were identified. CONCLUSION: The possible role of this polymorphism in disease states is discussed.

Isolation and characterization of two cytoplasmic hsp90s from Mytilus galloprovincialis (Mollusca: Bivalvia) that contain a complex promoter with a p53 binding site.

The commercially important marine bivalve Mytilus galloprovincialis (Mediterranean mussel) is considered a valuable bioindicator, due to its exposure to various pollutants and extreme environmental conditions. Environmental responsive genes, such as the hsp90s, protect the structure and function of cells and accomplish a significant task in cellular homeostasis. To study the hsp90s in M. galloprovincialis a genomic library was screened and two hsp90s were isolated. Sequence analysis revealed that the two genes exhibit great similarities in both the 5' non-coding and the coding region but differ in the 3' non-coding region, as well as in three introns, due to the presence of repeated sequences. Few synonymous substitutions in the coding region of the genes result to an identical predicted polypeptide, which belongs to the cytoplasmic HSP90 subfamily. The 5' non-coding region contains a non-translated exon and multiple binding sites for various transcription factors. The presence of a p53 binding site in the promoter of the isolated genes raises questions about the possible implication of hsp90s in the molluscan leukemia.

Three new satellite sequences and a mobile element found inside HSP70 introns of the Mediterranean mussel (Mytilus galloprovincialis).

We report the characterization of 3 new repetitive sequences from the bivalve mollusc Mytilus galloprovincialis, designated Mg1, Mg2, and Mg3, with monomer lengths of 169, 260, and 70 bp, respectively. The 3 repeats together constitute approximately 7.8% of the M. galloprovincialis genome and were found, together with ApaI-type 2 repeats, inside the introns of 2 genes of the HSP70 family, hsc70 and hsc71. Both the monomer length and the genomic content of the repeats indicate satellite sequences. The Mg1 repetitive region and its flanking sequences exhibit significant homology to CvE, a member of the Pearl family of mobile elements found in the eastern oyster (Crassostrea virginica). Thus, the whole homologous region is designated MgE, the first putative transposable element characterized in M. galloprovincialis. The ApaI, Mg2, and Mg3 repeats are continuously arranged inside the introns of both the hsc70 and hsc71 genes. The presence of perfect inverted repeats flanking the ApaI-Mg2-Mg3 repetitive region, as well as a sequence analysis of the repeats, indicates a transposition-like insertion of this region. The genes of the HSP70 family are highly conserved, and the presence of repetitive DNA or of mobile elements inside their introns is reported here for the first time.

Identification of several cytoplasmic HSP70 genes from the Mediterranean mussel (Mytilus galloprovincialis) and their long-term evolution in Mollusca and Metazoa.

The HSP70 protein family consists one of the most conserved and important systems for cellular homeostasis under both stress and physiological conditions. The genes of this family are poorly studied in Mollusca, which is the second largest metazoan phylum. To study these genes in Mollusca, we have isolated and identified five HSP70 genes from Mytilus galloprovincialis (Mediterranean mussel) and investigated their short-term evolution within Mollusca and their long-term evolution within Metazoa. Both sequence and phylogenetic analyses suggested that the isolated genes belong to the cytoplasmic (CYT) group of the HSP70 genes. Two of these genes probably represent cognates, whereas the remaining probably represent heat-inducible genes. Phylogenetic analysis including several molluscan CYT HSP70s reveals that the cognate genes in two species have very similar sequences and form intraspecies phylogenetic clades, differently from most metazoan cognate genes studied thus far, implying either recent gene duplications or concerted evolution. The M. galloprovincialis heat-inducible genes show intraspecies phylogenetic clustering, which in combination with the higher amino acid than nucleotide identity suggests that both gene conversion and purifying selection should be responsible for their sequence homogenization. Phylogenetic analysis including several metazoan HSP70s suggests that at least two types of CYT genes were present in the common ancestor of vertebrates and invertebrates, the first giving birth to the heat-inducible genes of invertebrates, whereas the other to both the heat-inducible genes of vertebrates and the cognate genes of all metazoans. These analyses also suggest that inducible and cognate genes seem to undergo divergent evolution.

Isolation, characterization, and localization of beta-tubulin genomic clones of three Drosophila montium subgroup species.

Genomic libraries were constructed from three Drosophila species, namely Drosophila auraria, Drosophila serrata, and Drosophila kikkawai, belonging to the Drosophila montium subgroup of the Drosophila melanogaster species group. Clones containing beta-tubulin specific sequences were isolated, characterized by restriction endonuclease digestions and Southern hybridizations, and mapped by in situ hybridization on the polytene chromosomes of the species studied. The distribution of the beta-tubulin loci was found to be similar in D. montium species and D. melanogaster.