Hidden genes in birds

We report that a subset of avian genes is characterized by very high GC content and long G/C stretches. These sequence characteristics correlate with the frequent absence of these genes from genomic databases. We provide several examples where genes in this subset are mistakenly reported as missing in birds.www.dx.doi.org/10.1186/s13059-015-0725-y

Electronic supplementary material

The online version of this article (doi:10.1186/s13059-015-0724-z) contains supplementary material, which is available to authorized users.     

Response to: the nature of evidence for and against epigenetic inheritance

We thank Dr. Nadeau for his interest in our work. Dr. Nadeau has raised concerns about the experimental approach (mouse strains, route of administration, lack of phenotypic assessment) and about the validity of our conclusions. We will respond to each of these concerns point-by point.Please see related article: www.dx.doi.org/10.1186/s13059-015-0709-y     

Predicting the spatial organization of chromosomes using epigenetic data

Chromosome folding can reinforce the demarcation between euchromatin and heterochromatin. Two new studies show how epigenetic data, including DNA methylation, can accurately predict chromosome folding in three dimensions. Such computational approaches reinforce the idea of a linkage between epigenetically marked chromatin domains and their segregation into distinct compartments at the megabase scale or topological domains at a higher resolution.Please see related articles: http://dx.doi.org/10.1186/s13059-015-0741-y and http://dx.doi.org/10.1186/s13059-015-0740-z     

Our unique microbial identity

A recent article examines the extent of individual variation in microbial identities and how this might determine disease susceptibility, therapeutic responses and recovery from clinical interventions.Please see related article: http://dx.doi.org/10.1186/s13059-015-0646-9     

Assembling allopolyploid genomes: no longer formidable

A combined approach of whole genome shotgun sequencing and ultra-high density linkage mapping using skim sequencing of a segregating population is effective for assembling allopolyploid genomes.See related Research, http://dx.doi.org/10.1186/s13059-015-0582-8     

Integrating host gene expression and the microbiome to explore disease pathogenesis

In a recent study, rich clinical assessment and longitudinal study design are combined with host gene expression and microbial sequencing analyses to develop a framework for exploring disease etiology and outcomes in the context of human inflammatory disease.See related article: http://dx.doi.org/10.1186/s13059-015-0637-x     

Marrying microfluidics and microwells for parallel,high-throughput single-cell genomics

An innovative, microwell-based platform for single-cell RNA sequencing (RNA-seq) combines cost efficiency, scalability and parallelizability, and will enable many new avenues of biological inquiry.See related Research article: http://dx.doi.org/10.1186/s13059-015-0684-3Over the past several years, it has become increasingly clear that there can be substantial variability in the behaviors of cells once deemed to be identical. This realization has brought about a renewed interest in defining cellular phenotypes and their variation, and in examining how these change under different biological contexts. To achieve this, approaches are needed that can deeply profile individual cells across diverse experimental conditions. Now, by marrying recent advances in molecular biology with microfluidics and microwells, Bose and colleagues present a new platform for achieving this goal [1], opening up exciting new opportunities to explore cells and their heterogeneity.     

High-resolution genomic analysis: the tumor-immune interface comes into focus

A genomic analysis of heterogeneous colorectal tumor samples has uncovered interactions between immunophenotype and various aspects of tumor biology, with implications for informing the choice of immunotherapies for specific patients and guiding the design of personalized neoantigen-based vaccines.Please see related article: http://dx.doi.org/10.1186/s13059-015-0620-6Immunotherapy is a promising new approach for treating human malignancies. Approximately 20% of melanoma and lung cancer patients receiving immune checkpoint inhibitors show responses [1,2]. Current major challenges include identification of patients most likely to respond to specific therapies and elucidation of novel targets to treat those who do not. To address these problems, a detailed understanding of the dynamic interactions between tumors and the immune system is required. In a new study, Zlatko Trajanoski and colleagues [3] describe a powerful approach to dissecting these issues through high-resolution analysis of patient genomic data. This study represents a significant advance over previous work from this group, which defined 28 immune-cell-type gene expression signatures and identified specific cell types as prognostic indicators in colorectal cancer (CRC) patients [4]. Here, the authors [3] integrate genomic analyses of CRC tumor molecular phenotypes, predicted antigenicity (called the ‘antigenome’), and immune-cell infiltration derived from multiple independent cohorts to gain refined insights into tumor-immune system interactions.     

The nature of evidence for and against epigenetic inheritance

Not so fast. The Iqbal et. al. study and the associated Whitelaw commentary highlight the appropriately high standards of study design and interpretation needed to obtain good evidence for or against epigenetic inheritance.Please see related article: www.dx.doi.org/10.1186/s13059-015-0714-1     

An Aerobic Exercise: Defining the Roles of Pseudomonas aeruginosa Terminal Oxidases

The opportunistic pathogen Pseudomonas aeruginosa encodes a large and diverse complement of aerobic terminal oxidases, which is thought to contribute to its ability to thrive in settings with low oxygen availability. In this issue, Arai et al. (J. Bacteriol. 196:4206–4215, 2014, doi:http://dx.doi.org/10.1128/JB.02176-14) present a thorough characterization of these five complexes, enabling a more detailed understanding of aerobic respiration in this organism.     

quantro: a data-driven approach to guide the choice of an appropriate normalization method

Normalization is an essential step in the analysis of high-throughput data. Multi-sample global normalization methods, such as quantile normalization, have been successfully used to remove technical variation. However, these methods rely on the assumption that observed global changes across samples are due to unwanted technical variability. Applying global normalization methods has the potential to remove biologically driven variation. Currently, it is up to the subject matter experts to determine if the stated assumptions are appropriate. Here, we propose a data-driven alternative. We demonstrate the utility of our method (quantro) through examples and simulations. A software implementation is available from http://www.bioconductor.org/packages/release/bioc/html/quantro.html.

Electronic supplementary material

The online version of this article (doi:10.1186/s13059-015-0679-0) contains supplementary material, which is available to authorized users.     

Genome sequence of the exopolysaccharide-producing Salipiger mucosus type strain (DSM 16094T), a moderately halophilic member of the Roseobacter clade

Salipiger mucosus Martínez-Cànovas et al. 2004 is the type species of the genus Salipiger, a moderately halophilic and exopolysaccharide-producing representative of the Roseobacter lineage within the alphaproteobacterial family Rhodobacteraceae. Members of this family were shown to be the most abundant bacteria especially in coastal and polar waters, but were also found in microbial mats and sediments. Here we describe the features of the S. mucosus strain DSM 16094^T together with its genome sequence and annotation. The 5,689,389-bp genome sequence consists of one chromosome and several extrachromosomal elements. It contains 5,650 protein-coding genes and 95 RNA genes. The genome of S. mucosus DSM 16094^T was sequenced as part of the activities of the Transregional Collaborative Research Center 51 (TRR51) funded by the German Research Foundation (DFG).     

High quality draft genome sequence of Olivibacter sitiensis type strain (AW-6T), a diphenol degrader with genes involved in the catechol pathway

Olivibacter sitiensis Ntougias et al. 2007 is a member of the family Sphingobacteriaceae, phylum Bacteroidetes. Members of the genus Olivibacter are phylogenetically diverse and of significant interest. They occur in diverse habitats, such as rhizosphere and contaminated soils, viscous wastes, composts, biofilter clean-up facilities on contaminated sites and cave environments, and they are involved in the degradation of complex and toxic compounds. Here we describe the features of O. sitiensis AW-6^T, together with the permanent-draft genome sequence and annotation. The organism was sequenced under the Genomic Encyclopedia for Bacteria and Archaea (GEBA) project at the DOE Joint Genome Institute and is the first genome sequence of a species within the genus Olivibacter. The genome is 5,053,571 bp long and is comprised of 110 scaffolds with an average GC content of 44.61%. Of the 4,565 genes predicted, 4,501 were protein-coding genes and 64 were RNA genes. Most protein-coding genes (68.52%) were assigned to a putative function. The identification of 2-keto-4-pentenoate hydratase/2-oxohepta-3-ene-1,7-dioic acid hydratase-coding genes indicates involvement of this organism in the catechol catabolic pathway. In addition, genes encoding for β-1,4-xylanases and β-1,4-xylosidases reveal the xylanolytic action of O. sitiensis.     

Bacteria in Solitary Confinement

Even in clonal bacterial cultures, individual bacteria can show substantial stochastic variation, leading to pitfalls in the interpretation of data derived from millions of cells in a culture. In this issue of the Journal of Bacteriology, as part of their study on osmoadaptation in a cyanobacterium, Nanatani et al. describe employing an ingenious microfluidic device that gently cages individual cells (J Bacteriol 197:676–687, 2015, http://dx.doi.org/10.1128/JB.02276-14). The device is a welcome addition to the toolkit available to probe the responses of individual cells to environmental cues.     

Reinterpreting Long-Term Evolution Experiments: Is Delayed Adaptation an Example of Historical Contingency or a Consequence of Intermittent Selection?

Van Hofwegen et al. demonstrated that Escherichia coli rapidly evolves the ability to use citrate when long selective periods are provided (D. J. Van Hofwegen, C. J. Hovde, and S. A. Minnich, J Bacteriol 198:1022–1034, 2016, http://dx.doi.org/10.1128/JB.00831-15). This contrasts with the extreme delay (15 years of daily transfers) seen in the long-term evolution experiments of Lenski and coworkers. Their idea of “historical contingency” may require reinterpretation. Rapid evolution seems to involve selection for duplications of the whole cit locus that are too unstable to contribute when selection is provided in short pulses.     

Population Bottlenecks and Pathogen Extinction: “Make This Everyone's Mission to Mars,Including Yours”

Kapusinszky et al. (J Virol 89:8152–8161, 2015, http://dx.doi.org/10.1128/JVI.00671-15) report that host population bottlenecks may result in pathogen extinction, which provides a compelling argument for an alternative approach to vaccination for the control of virus spread. By comparing the prevalence levels of three viral pathogens in two populations of African green monkeys (AGMs) (Chlorocebus sabaeus) from Africa and two Caribbean Islands, they convincingly show that a major host bottleneck resulted in the eradication of select pathogens from a given host.     

Genome sequence of the Thermotoga thermarum type strain (LA3T) from an African solfataric spring

Thermotoga thermarum Windberger et al. 1989 is a member to the genomically well characterized genus Thermotoga in the phylum ‘Thermotogae’. T. thermarum is of interest for its origin from a continental solfataric spring vs. predominantly marine oil reservoirs of other members of the genus. The genome of strain LA3T also provides fresh data for the phylogenomic positioning of the (hyper-)thermophilic bacteria. T. thermarum strain LA3^T is the fourth sequenced genome of a type strain from the genus Thermotoga, and the sixth in the family Thermotogaceae to be formally described in a publication. Phylogenetic analyses do not reveal significant discrepancies between the current classification of the group, 16S rRNA gene data and whole-genome sequences. Nevertheless, T. thermarum significantly differs from other Thermotoga species regarding its iron-sulfur cluster synthesis, as it contains only a minimal set of the necessary proteins. Here we describe the features of this organism, together with the complete genome sequence and annotation. The 2,039,943 bp long chromosome with its 2,015 protein-coding and 51 RNA genes is a part of the Genomic Encyclopedia of Bacteria and Archaea project.     

Genome sequence of the free-living aerobic spirochete Turneriella parva type strain (HT), and emendation of the species Turneriella parva

Turneriella parva Levett et al. 2005 is the only species of the genus Turneriella which was established as a result of the reclassification of Leptospira parva Hovind-Hougen et al. 1982. Together with Leptonema and Leptospira, Turneriella constitutes the family Leptospiraceae, within the order Spirochaetales. Here we describe the features of this free-living aerobic spirochete together with the complete genome sequence and annotation. This is the first complete genome sequence of a member of the genus Turneriella and the 13^th member of the family Leptospiraceae for which a complete or draft genome sequence is now available. The 4,409,302 bp long genome with its 4,169 protein-coding and 45 RNA genes is part of the Genomic Encyclopedia of Bacteria and Archaea project.     

Genome sequence of Frateuria aurantia type strain (Kond? 67T), a xanthomonade isolated from Lilium auratium Lindl.

Frateuria aurantia (ex Kondô and Ameyama 1958) Swings et al. 1980 is a member of the bispecific genus Frateuria in the family Xanthomonadaceae, which is already heavily targeted for non-type strain genome sequencing. Strain Kondô 67^T was initially (1958) identified as a member of ‘Acetobacter aurantius’, a name that was not considered for the approved list. Kondô 67^T was therefore later designated as the type strain of the newly proposed acetogenic species Frateuria aurantia. The strain is of interest because of its triterpenoids (hopane family). F. aurantia Kondô 67^T is the first member of the genus Frateura whose genome sequence has been deciphered, and here we describe the features of this organism, together with the complete genome sequence and annotation. The 3,603,458-bp long chromosome with its 3,200 protein-coding and 88 RNA genes is a part of the Genomic Encyclopedia of Bacteria and Archaea project.