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Using the Cap Analysis of Gene Expression (CAGE) technology, the FANTOM5 consortium provided one of the most comprehensive maps of transcription start sites (TSSs) in several species. Strikingly, ~72% of them could not be assigned to a specific gene and initiate at unconventional regions, outside promoters or enhancers. Here, we probe these unassigned TSSs and show that, in all species studied, a significant fraction of CAGE peaks initiate at microsatellites, also called short tandem repeats (STRs). To confirm this transcription, we develop Cap Trap RNA-seq, a technology which combines cap trapping and long read MinION sequencing. We train sequence-based deep learning models able to predict CAGE signal at STRs with high accuracy. These models unveil the importance of STR surrounding sequences not only to distinguish STR classes, but also to predict the level of transcription initiation. Importantly, genetic variants linked to human diseases are preferentially found at STRs with high transcription initiation level, supporting the biological and clinical relevance of transcription initiation at STRs. Together, our results extend the repertoire of non-coding transcription associated with DNA tandem repeats and complexify STR polymorphism., Nature Communications, 12 (1), ISSN:2041-1723

As permanent residents of the normal gut microbiota, bifidobacteria have evolved to adapt to the host's immune response whose priority is to eliminate pathogenic agents. The mechanisms that ensure the survival of commensals during inflammation and maintain the stability of the core component of the normal gut microbiota in such conditions remain poorly understood. We propose a new in vitro approach to study the mechanisms of resistance to immune response factors based on high-throughput sequencing followed by transcriptome analysis. This approach allowed us to detect differentially expressed genes associated with inflammation. In this study, we demonstrated that the presence of the pro-inflammatory cytokines IL-6 and TNFα to the growth medium of the B. longum subsp. longum GT15 strain changes the latter's growth rate insignificantly while affecting the expression of certain genes. We identified these genes and performed a COG and a KEGG pathway enrichment analysis. Using phylogenetic profiling we predicted the operons of genes whose expression was triggered by the cytokines TNFα and IL-6 in vitro. By mapping the transcription start points, we experimentally validated the predicted operons. Thus, in this study, we predicted the genes involved in a putative signaling pathway underlying the mechanisms of resistance to inflammatory factors in bifidobacteria. Since bifidobacteria are a major component of the human intestinal microbiota exhibiting pronounced anti-inflammatory properties, this study is of great practical and scientific relevance.

The human gastrointestinal microbiota (HGM) is known for its rich diversity of bacterial species and strains. Yet many studies stop at characterizing the HGM at the family level. This is mainly due to lack of adequate methods for a high-resolution profiling of the HGM. One way to characterize the strain diversity of the HGM is to look for strain-specific functional markers. Here, we propose using type II toxin-antitoxin systems (TAS). To identify TAS systems in the HGM, we previously developed the software TAGMA. This software was designed to detect the TAS systems, MazEF and RelBE, in lactobacilli and bifidobacteria. In this study, we updated the gene catalog created previously and used it to test our software anew on 1346 strains of bacteria, which belonged to 489 species and 49 genera. We also sequenced the genomes of 20 fecal samples and analyzed the results with TAGMA. Although some differences were detected at the strain level, the results showed no particular difference in the bacterial species between our method and other classic analysis software. These results support the use of the updated catalog of genes encoding type II TAS as a useful tool for computer-assisted species and strain characterization of the HGM.

Fagopyrum esculentum (common buckwheat) is an important agricultural non-cereal grain plant. Despite extensive genetic studies, the information on its mitochondrial genome is still lacking. Using long reads generated by single-molecule real-time technology coupled with circular consensus sequencing (CCS) protocol, we assembled the buckwheat mitochondrial genome and detected that its prevalent form consists of 10 circular chromosomes with a total length of 404 Kb. In order to confirm the presence of a multipartite structure, we developed a new targeted assembly tool capable of processing long reads. The mitogenome contains all genes typical for plant mitochondrial genomes and long inserts of plastid origin (~6.4% of the total mitogenome length). Using this new information, we characterized the genetic diversity of mitochondrial and plastid genomes in 11 buckwheat cultivars compared with the ancestral subspecies, F. esculentum ssp. ancestrale. We found it to be surprisingly low within cultivars: Only three to six variations in the mitogenome and one to two in the plastid genome. In contrast, the divergence with F. esculentum ssp. ancestrale is much higher: 220 positions differ in the mitochondrial genome and 159 in the plastid genome. The SNPs in the plastid genome are enriched in non-synonymous substitutions, in particular in the genes involved in photosynthesis: psbA, psbC, and psbH. This presumably reflects the selection for the increased photosynthesis efficiency as a part of the buckwheat breeding program.

Shepherd&rsquo, s purse (Capsella bursa-pastoris) is a cosmopolitan annual weed and a promising model plant for studying allopolyploidization in the evolution of angiosperms. Though plant mitochondrial genomes are a valuable source of genetic information, they are hard to assemble. At present, only the complete mitogenome of C. rubella is available out of all species of the genus Capsella. In this work, we have assembled the complete mitogenome of C. bursa-pastoris using high-precision PacBio SMRT third-generation sequencing technology. It is 287,799 bp long and contains 32 protein-coding genes, 3 rRNAs, 25 tRNAs corresponding to 15 amino acids, and 8 open reading frames (ORFs) supported by RNAseq data. Though many repeat regions have been found, none of them is longer than 1 kbp, and the most frequent structural variant originated from these repeats is present in only 4% of the mitogenome copies. The mitochondrial DNA sequence of C. bursa-pastoris differs from C. rubella, but not from C. orientalis, by two long inversions, suggesting that C. orientalis could be its maternal progenitor species. In total, 377 C to U RNA editing sites have been detected. All genes except cox1 and atp8 contain RNA editing sites, and most of them lead to non-synonymous changes of amino acids. Most of the identified RNA editing sites are identical to corresponding RNA editing sites in A. thaliana.

Background Salivary cell secretion (SCS) plays a critical role in blood feeding by medicinal leeches, making them of use for certain medical purposes even today. Results We annotated the Hirudo medicinalis genome and performed RNA-seq on salivary cells isolated from three closely related leech species, H. medicinalis, Hirudo orientalis, and Hirudo verbana. Differential expression analysis verified by proteomics identified salivary cell-specific gene expression, many of which encode previously unknown salivary components. However, the genes encoding known anticoagulants have been found to be expressed not only in salivary cells. The function-related analysis of the unique salivary cell genes enabled an update of the concept of interactions between salivary proteins and components of haemostasis. Conclusions Here we report a genome draft of Hirudo medicinalis and describe identification of novel salivary proteins and new homologs of genes encoding known anticoagulants in transcriptomes of three medicinal leech species. Our data provide new insights in genetics of blood-feeding lifestyle in leeches.

A great amount of attention has been paid to the study of the microbiota–gut–brain axis in recent years. Gut microbiota can affect development and functioning of the brain through synthesis of various neuroactive metabolites, such as neurotransmitters, hormones, and other compounds. In the present study, the presence and distribution are analyzed for the genes controlling the synthesis of enzymes involved in production of neuroactive compounds in 147 gut metagenomes of healthy people from Human Microbiome Project database and synthetic metagenome artificially assembled from 508 bacterial genomes. The analysis is conducted using the collected catalog of orthologs for 17 key enzymes and an algorithm developed for their search. As a result of analyses of genomic and metagenomic data of healthy people, seven bacterial genera containing the greatest number of enzyme genes and 8 enzymes out of 17 that are observed the most frequently are chosen. It is assumed that the selected “core” genera and enzymes form a metagenomic signature reflecting the neurometabolic potential of the human intestinal microbiota in the norm.

The vast diversity of Orchidaceae together with sophisticated adaptations to pollinators and other unique features make this family an attractive model for evolutionary and functional studies. The sequenced genome of Phalaenopsis equestris facilitates Orchidaceae research. Here we present an RNA-seq based transcriptome map of P. equestris which covers 19 organs of the plant including leaves, roots, floral organs and shoot apical meristem. We demonstrated the high quality of the data and showed the similarity of P. equestris transcriptome map with gene expression atlases of other plants. The transcriptome map can be easily accessed through our database Transcriptome Variation Analysis (TraVA) visualizing gene expression profiles. As an example of the application we analyzed the expression of Phalaenopsis “orphan” genes – the ones that do not have recognizable similarity with genes of other plants. We found that about a half of them are not expressed; the ones that are expressed have a predominant expression pattern in reproductive structures.

Background Transcriptome map is a powerful tool for a variety of biological studies; transcriptome maps that include different organs, tissues, cells and stages of development are currently available for at least 30 plants. Some of them include samples treated by environmental or biotic stresses. However, most studies explore only limited set of organs and developmental stages (leaves or seedlings). In order to provide broader view of organ-specific strategies of cold stress response we studied expression changes that follow exposure to cold (+ 4 °C) in different aerial parts of plant: cotyledons, hypocotyl, leaves, young flowers, mature flowers and seeds using RNA-seq. Results The results on differential expression in leaves are congruent with current knowledge on stress response pathways, in particular, the role of CBF genes. In other organs, both essence and dynamics of gene expression changes are different. We show the involvement of genes that are confined to narrow expression patterns in non-stress conditions into stress response. In particular, the genes that control cell wall modification in pollen, are activated in leaves. In seeds, predominant pattern is the change of lipid metabolism. Conclusions Stress response is highly organ-specific; different pathways are involved in this process in each type of organs. The results were integrated with previously published transcriptome map of Arabidopsis thaliana and used for an update of a public database TraVa: http://travadb.org/browse/Species=AthStress. Electronic supplementary material The online version of this article (10.1186/s12870-019-1636-y) contains supplementary material, which is available to authorized users.

Cysteine-rich peptides (CRPs) play an important role in plant physiology. However, their role in resistance induced by biogenic elicitors remains poorly understood. Using whole-genome transcriptome sequencing and our CRP search algorithm, we analyzed the repertoire of CRPs in tomato Solanum lycopersicum L. in response to Fusarium oxysporum infection and elicitors from F. sambucinum. We revealed 106 putative CRP transcripts belonging to different families of antimicrobial peptides (AMPs), signaling peptides (RALFs), and peptides with non-defense functions (Major pollen allergen of Olea europaea (Ole e 1 and 6), Maternally Expressed Gene (MEG), Epidermal Patterning Factor (EPF)), as well as pathogenesis-related proteins of families 1 and 4 (PR-1 and 4). We discovered a novel type of 10-Cys-containing hevein-like AMPs named SlHev1, which was up-regulated both by infection and elicitors. Transcript profiling showed that F. oxysporum infection and F. sambucinum elicitors changed the expression levels of different overlapping sets of CRP genes, suggesting the diversification of functions in CRP families. We showed that non-specific lipid transfer proteins (nsLTPs) and snakins mostly contribute to the response of tomato plants to the infection and the elicitors. The involvement of CRPs with non-defense function in stress reactions was also demonstrated. The results obtained shed light on the mode of action of F. sambucinum elicitors and the role of CRP families in the immune response in tomato.

Antimicrobial peptides (AMPs) are the main components of the plant innate immune system. Defensins represent the most important AMP family involved in defense and non-defense functions. In this work, global RNA sequencing and de novo transcriptome assembly were performed to explore the diversity of defensin-like (DEFL) genes in the wheat Triticum kiharae and to study their role in induced resistance (IR) mediated by the elicitor metabolites of a non-pathogenic strain FS-94 of Fusarium sambucinum. Using a combination of two pipelines for DEFL mining in transcriptome data sets, as many as 143 DEFL genes were identified in T. kiharae, the vast majority of them represent novel genes. According to the number of cysteine residues and the cysteine motif, wheat DEFLs were classified into ten groups. Classical defensins with a characteristic 8-Cys motif assigned to group 1 DEFLs represent the most abundant group comprising 52 family members. DEFLs with a characteristic 4-Cys motif CX{3,5}CX{8,17}CX{4,6}C named group 4 DEFLs previously found only in legumes were discovered in wheat. Within DEFL groups, subgroups of similar sequences originated by duplication events were isolated. Variation among DEFLs within subgroups is due to amino acid substitutions and insertions/deletions of amino acid sequences. To identify IR-related DEFL genes, transcriptional changes in DEFL gene expression during elicitor-mediated IR were monitored. Transcriptional diversity of DEFL genes in wheat seedlings in response to the fungus Fusarium oxysporum, FS-94 elicitors, and the combination of both (elicitors + fungus) was demonstrated, with specific sets of up- and down-regulated DEFL genes. DEFL expression profiling allowed us to gain insight into the mode of action of the elicitors from F. sambucinum. We discovered that the elicitors up-regulated a set of 24 DEFL genes. After challenge inoculation with F. oxysporum, another set of 22 DEFLs showed enhanced expression in IR-displaying seedlings. These DEFLs, in concert with other defense molecules, are suggested to determine enhanced resistance of elicitor-pretreated wheat seedlings. In addition to providing a better understanding of the mode of action of the elicitors from FS-94 in controlling diseases, up-regulated IR-specific DEFL genes represent novel candidates for genetic transformation of plants and development of pathogen-resistant crops.

Salivary cell secretion (SCS) plays a critical role in blood feeding by medicinal leeches, making them of use for certain medical purposes even today. We annotated theHirudo medicinalisgenome and performed RNA-seq on salivary cells isolated from three closely related leech species,H. medicinalis, Hirudo orientalis,andHirudo verbana.Differential expression analysis verified by proteomics identified salivary cell-specific genes, many of which encode previously unknown salivary components. However, the genes encoding known anticoagulants were not differentially expressed in the salivary cells. The function-related analysis of the unique salivary cell genes enabled an update of the concept of interactions between salivary proteins and components of haemostasis. Thus, our study provides one of the most comprehensive knowledge of the genetic fundamentals of the blood-sucking lifestyle in leeches.

Background Gray whale, Eschrichtius robustus (E. robustus), is a single member of the family Eschrichtiidae, which is considered to be the most primitive in the class Cetacea. Gray whale is often described as a “living fossil”. It is adapted to extreme marine conditions and has a high life expectancy (77 years). The assembly of a gray whale genome and transcriptome will allow to carry out further studies of whale evolution, longevity, and resistance to extreme environment. Results In this work, we report the first de novo assembly and primary analysis of the E. robustus genome and transcriptome based on kidney and liver samples. The presented draft genome assembly is complete by 55% in terms of a total genome length, but only by 24% in terms of the BUSCO complete gene groups, although 10,895 genes were identified. Transcriptome annotation and comparison with other whale species revealed robust expression of DNA repair and hypoxia-response genes, which is expected for whales. Conclusions This preliminary study of the gray whale genome and transcriptome provides new data to better understand the whale evolution and the mechanisms of their adaptation to the hypoxic conditions. Electronic supplementary material The online version of this article (doi: 10.1186/s12862-017-1103-z) contains supplementary material, which is available to authorized users.

Maturation of the neocortex during the first three postnatal weeks is a complex process that is characterized by different time courses of maturation of different areas of the neocortex. Analysis of gene expression using quantitative PCR after reverse transcription during this period of ontogeny and comparison of different cortical areas require optimal selection of reference genes for correct normalization of the data. Here, we compared expression of nine reference genes in the somatosensory and visual areas of the neocortex at the age of 5, 8, 10, 13, and 20 days. Using widely used GeNorm and NormFinder applications, as well as a novel approach, we compared stability of expression of GAPDH, YWHAZ, TFR1, RPS18, Rn18S, HPRT1, KIF5C, OSBP, and UQCRFS1. We found that, in both neocortical areas studied, YWHAZ and UQCRFS1 are the best reference genes whereas GAPDH and TFR1 are also stably expressed in the somatosensory cortex and OSBP is stable in the visual cortex. Additionally, analysis of stability of expression of these genes by a novel approach showed that the expression of these genes is stable during the entire period from the 5th to the 20th postnatal days.

Gammaproteobacterium Thalassolituus oleivorans plays an important role in oil degradation in sea water through emulsifying crude oil and alkanes at low temperatures in polar sea environment. Here we report the complete genome sequence of K-188 strain (VKPM B-9394) isolated in the Barents Sea and compare it with other known Thalassolituus oleivorans strains. The Thalassolituus strains are differed in orthologs number of the genes of alkane degradation, transport proteins, genes of sugar utilization, endonucleases, signaling proteins, transcriptional regulators and presence of CRISPR/Cas locus. Also only the genome of K-188 contains the 3-hydroxyalkanoate synthetase.

BackgroundRNA-seq is a useful tool for analysis of gene expression. However, its robustness is greatly affected by a number of artifacts. One of them is the presence of duplicated reads.ResultsTo infer the influence of different methods of removal of duplicated reads on estimation of gene expression in cancer genomics, we analyzed paired samples of hepatocellular carcinoma (HCC) and non-tumor liver tissue. Four protocols of data analysis were applied to each sample: processing without deduplication, deduplication using a method implemented in samtools, and deduplication based on one or two molecular indices (MI). We also analyzed the influence of sequencing layout (single read or paired end) and read length. We found that deduplication without MI greatly affects estimated expression values; this effect is the most pronounced for highly expressed genes.ConclusionThe use of unique molecular identifiers greatly improves accuracy of RNA-seq analysis, especially for highly expressed genes. We developed a set of scripts that enable handling of MI and their incorporation into RNA-seq analysis pipelines. Deduplication without MI affects results of differential gene expression analysis, producing a high proportion of false negative results. The absence of duplicate read removal is biased towards false positives. In those cases where using MI is not possible, we recommend using paired-end sequencing layout.

Non-specific lipid-transfer proteins (nsLTPs) represent a family of plant antimicrobial peptides (AMPs) implicated in diverse physiological processes. However, their role in induced resistance (IR) triggered by non-pathogenic fungal strains and their metabolites is poorly understood. In this work, using RNA-seq data and our AMP search pipeline, we analyzed the repertoire of nsLTP genes in the wheat Triticum kiharae and studied their expression in response to Fusarium oxysporum infection and treatment with the intracellular metabolites of Fusarium sambucinum FS-94. A total of 243 putative nsLTPs were identified, which were classified into five structural types and characterized. Expression analysis showed that 121 TkLTPs including sets of paralogs with identical mature peptides displayed specific expression patters in response to different treatments pointing to their diverse roles in resistance development. We speculate that upregulated nsLTP genes are involved in protection due to their antimicrobial activity or signaling functions. Furthermore, we discovered that in IR-displaying plants, a vast majority of nsLTP genes were downregulated, suggesting their role as negative regulators of immune mechanisms activated by the FS-94 elicitors. The results obtained add to our knowledge of the role of nsLTPs in IR and provide candidate molecules for genetic engineering of crops to enhance disease resistance.

The knowledge of gene functions in model organisms is the starting point for the analysis of gene function in non-model species, including economically important ones. Usually, the assignment of gene functions is based on sequence similarity. In plants, due to a highly intricate gene landscape, this approach has some limitations. It is often impossible to directly match gene sets from one plant species to another species based only on their sequences. Thus, it is necessary to use additional information to identify functionally similar genes. Expression patterns have great potential to serve as a source of such information. An important prerequisite for the comparative analysis of transcriptomes is the existence of high-resolution expression maps consisting of comparable samples. Here, we present a transcriptome atlas of tomato (Solanum lycopersicum) consisting of 30 samples of different organs and developmental stages. The samples were selected in a way that allowed for side-by-side comparison with the Arabidopsis thaliana transcriptome map. Newly obtained data are integrated in the TraVA database and are available online, together with tools for their analysis. In this paper, we demonstrate the potential of comparing transcriptome maps for inferring shifts in the expression of paralogous genes.

Summary Arabidopsis thaliana is a long established model species for plant molecular biology, genetics and genomics, and studies of A.thaliana gene function provide the basis for formulating hypotheses and designing experiments involving other plants, including economically important species. A comprehensive understanding of the A.thaliana genome and a detailed and accurate understanding of the expression of its associated genes is therefore of great importance for both fundamental research and practical applications. Such goal is reliant on the development of new genetic and genomic resources, involving new methods of data acquisition and analysis. We present here the genome-wide analysis of A.thaliana gene expression profiles across different organs and developmental stages using high-throughput transcriptome sequencing. The expression of 25,706 protein-coding genes, as well as their stability and their spatiotemporal specificity, was assessed in 79 organs and developmental stages. A search for alternative splicing events identified 37,873 previously unreported splice junctions, approximately 30% of occurred in intergenic regions. These potentially represent novel spliced genes that are not included in the TAIR10 database. These data are housed in an open-access web-based database, TraVA (Transcriptome Variation Analysis, http://travadb.org/), which allows visualization and analysis of gene expression profiles and differential gene expression between organs and developmental stages. This article is protected by copyright. All rights reserved.

X chromosomes are unusual in many regards, not least of which is their nonrandom gene content. The causes of this bias are commonly discussed in the context of sexual antagonism and the avoidance of activity in the male germline. Here, we examine the notion that, at least in some taxa, functionally biased gene content may more profoundly be shaped by limits imposed on gene expression owing to haploid expression of the X chromosome. Notably, if the X, as in primates, is transcribed at rates comparable to the ancestral rate (per promoter) prior to the X chromosome formation, then the X is not a tolerable environment for genes with very high maximal net levels of expression, owing to transcriptional traffic jams. We test this hypothesis using The Encyclopedia of DNA Elements (ENCODE) and data from the Functional Annotation of the Mammalian Genome (FANTOM5) project. As predicted, the maximal expression of human X-linked genes is much lower than that of genes on autosomes: on average, maximal expression is three times lower on the X chromosome than on autosomes. Similarly, autosome-to-X retroposition events are associated with lower maximal expression of retrogenes on the X than seen for X-to-autosome retrogenes on autosomes. Also as expected, X-linked genes have a lesser degree of increase in gene expression than autosomal ones (compared to the human/Chimpanzee common ancestor) if highly expressed, but not if lowly expressed. The traffic jam model also explains the known lower breadth of expression for genes on the X (and the Z of birds), as genes with broad expression are, on average, those with high maximal expression. As then further predicted, highly expressed tissue-specific genes are also rare on the X and broadly expressed genes on the X tend to be lowly expressed, both indicating that the trend is shaped by the maximal expression level not the breadth of expression per se. Importantly, a limit to the maximal expression level explains biased tissue of expression profiles of X-linked genes. Tissues whose tissue-specific genes are very highly expressed (e.g., secretory tissues, tissues abundant in structural proteins) are also tissues in which gene expression is relatively rare on the X chromosome. These trends cannot be fully accounted for in terms of alternative models of biased expression. In conclusion, the notion that it is hard for genes on the Therian X to be highly expressed, owing to transcriptional traffic jams, provides a simple yet robustly supported rationale of many peculiar features of X’s gene content, gene expression, and evolution., Laurence Hurst, Lukasz Huminiecki, and the FANTOM5 consortium propose a new explanation for the peculiar expression properties of genes on the human X chromosome, based on the premise that very high expression levels cannot be achieved on a haploid-expressed chromosome., Author Summary Genes located on the human X chromosome are not a random mix of genes: they tend to be expressed in relatively few tissues or are specific for a particular set of tissues, e.g., brain regions. Prior attempts to explain this skewed gene content have hypothesized that the X chromosome might be peculiar because it has to balance mutations that are advantageous to one sex but deleterious to the other, or because it has to shut down during the process of sperm manufacture in males. Here we suggest and test a third possible explanation: that genes on the X chromosome are limited in their transcription levels and thus tend to be genes that are lowly or specifically expressed. We consider the suggestion that since these genes can only be expressed from one chromosome, as males only have one X, the ability to express a gene at very high rates is limited owing to potential transcriptional traffic jams. As predicted, we find that human X-located genes have maximal expression rates far below that of genes residing on autosomes. When we look at genes that have moved onto or off the X chromosome during recent evolution, we find the maximal expression is higher when not on the X chromosome. We also find that X-located genes that are relatively highly expressed are not able to increase their expression level further. Our model explains both the enrichment for tissue specificity and the paucity of certain tissues with X-located genes. Genes underrepresented on the X are either expressed in many tissues—such genes tend to have high maximal expression—or are from tissues that require a lot of transcription (e.g., fast secreting tissues like the liver). Just as many of the findings cannot be explained by the two earlier models, neither can the traffic jam model explain all the peculiar features of the genes found on the X chromosome. Indeed, we find evidence of a reproduction-related bias in X-located genes, even after allowing for the traffic jam problem.

In this study, we report the first completely annotated genome sequence of the Russian-origin Bifidobacterium longum subsp. longum strain GT15. We discovered 35 unique genes (UGs) which were detected from only the B. longum GT15 genome and were absent from other B. longum strain genomes (not of Russian origin).

We report here a sequence of the genome of the Streptomyces fradiae ATCC 19609 strain, initially isolated from the soil, which produces tylosin. S. fradiae is highly sensitive to different classes of antibiotics, compared to the sensitivities of other bacteria. We have identified 9 groups of genes directly or indirectly involved in the resistome formation.

In this study, we report the first completely annotated genome sequence of the Russia origin Bifidobacterium longum subsp. longum strain GT15. Comparative genomic analysis of this genome with other available completely annotated genome sequences of B. longum strains isolated from other countries has revealed a high degree of conservation and synteny across the entire genomes. However, it was discovered that the open reading frames to 35 genes were detected only from the B. longum GT15 genome and absent from other genomes B. longum strains (not of Russian origin). These so-called unique genes (UGs) represent a total length of 39,066 bp, with G + C content ranging from 37 to 65 %. Interestingly, certain genes were detected in other B. longum strains of Russian origin. In our analysis, we examined genes for global regulatory systems: proteins of toxin–antitoxin (TA) systems type II, serine/threonine protein kinases (STPKs) of eukaryotic type, and genes of the WhiB-like family proteins. In addition, we have made in silico analysis of all the most significant probiotic genes and considered genes involved in epigenetic regulation and genes responsible for producing various neuromediators. This genome sequence may elucidate the biology of this probiotic strain as a promising candidate for practical (pharmaceutical) applications.

Naturally occurring regulatory T (Treg) cells, which specifically express the transcription factor forkhead box P3 (Foxp3), are engaged in the maintenance of immunological self-tolerance and homeostasis. By transcriptional start site cluster analysis, we assessed here how genome-wide patterns of DNA methylation or Foxp3 binding sites were associated with Treg-specific gene expression. We found that Treg-specific DNA hypomethylated regions were closely associated with Treg up-regulated transcriptional start site clusters, whereas Foxp3 binding regions had no significant correlation with either up- or down-regulated clusters in nonactivated Treg cells. However, in activated Treg cells, Foxp3 binding regions showed a strong correlation with down-regulated clusters. In accordance with these findings, the above two features of activation-dependent gene regulation in Treg cells tend to occur at different locations in the genome. The results collectively indicate that Treg-specific DNA hypomethylation is instrumental in gene up-regulation in steady state Treg cells, whereas Foxp3 down-regulates the expression of its target genes in activated Treg cells. Thus, the two events seem to play distinct but complementary roles in Treg-specific gene expression.

Motivation: Modern experimental methods provide substantial information on protein–DNA recognition. Studying arrangements of transcription factor binding sites (TFBSs) of interacting transcription factors (TFs) advances understanding of the transcription regulatory code. Results: We constructed binding motifs for TFs forming a complex with HIF-1α at the erythropoietin 3′-enhancer. Corresponding TFBSs were predicted in the segments around transcription start sites (TSSs) of all human genes. Using the genome-wide set of regulatory regions, we observed several strongly preferred distances between hypoxia-responsive element (HRE) and binding sites of a particular cofactor protein. The set of preferred distances was called as a preferred pair distance template (PPDT). PPDT dramatically depended on the TF and orientation of its binding sites relative to HRE. PPDT evaluated from the genome-wide set of regulatory sequences was used to detect significant PPDT-consistent binding site pairs in regulatory regions of hypoxia-responsive genes. We believe PPDT can help to reveal the layout of eukaryotic regulatory segments. Contact: ivan.kulakovskiy@gmail.com Supplementary information: Supplementary data are available at Bioinformatics online.

Regulated transcription controls the diversity, developmental pathways and spatial organization of the hundreds of cell types that make up a mammal. Using single-molecule cDNA sequencing, we mapped transcription start sites (TSSs) and their usage in human and mouse primary cells, cell lines and tissues to produce a comprehensive overview of mammalian gene expression across the human body. We find that few genes are truly 'housekeeping', whereas many mammalian promoters are composite entities composed of several closely separated TSSs, with independent cell-type-specific expression profiles. TSSs specific to different cell types evolve at different rates, whereas promoters of broadly expressed genes are the most conserved. Promoter-based expression analysis reveals key transcription factors defining cell states and links them to binding-site motifs. The functions of identified novel transcripts can be predicted by coexpression and sample ontology enrichment analyses. The functional annotation of the mammalian genome 5 (FANTOM5) project provides comprehensive expression profiles and functional annotation of mammalian cell-type-specific transcriptomes with wide applications in biomedical research.