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The mammalian immune system implements a remarkably effective set of mechanisms for fighting pathogens1. Its main components are haematopoietic immune cells, including myeloid cells that control innate immunity, and lymphoid cells that constitute adaptive immunity2. However, immune functions are not unique to haematopoietic cells, and many other cell types display basic mechanisms of pathogen defence3–5. To advance our understanding of immunology outside the haematopoietic system, here we systematically investigate the regulation of immune genes in the three major types of structural cells: epithelium, endothelium and fibroblasts. We characterize these cell types across twelve organs in mice, using cellular phenotyping, transcriptome sequencing, chromatin accessibility profiling and epigenome mapping. This comprehensive dataset revealed complex immune gene activity and regulation in structural cells. The observed patterns were highly organ-specific and seem to modulate the extensive interactions between structural cells and haematopoietic immune cells. Moreover, we identified an epigenetically encoded immune potential in structural cells under tissue homeostasis, which was triggered in response to systemic viral infection. This study highlights the prevalence and organ-specific complexity of immune gene activity in non-haematopoietic structural cells, and it provides a high-resolution, multi-omics atlas of the epigenetic and transcriptional networks that regulate structural cells in the mouse. Structural cells implement a broad range of immune-regulatory functions beyond their roles as barriers and connective tissues, and they utilize an epigenetically encoded potential for immune gene activation in their rapid response to viral infection.

The underrepresentation of non-Europeans in human genetic studies so far has limited the diversity of individuals in genomic datasets and led to reduced medical relevance for a large proportion of the world’s population. Population-specific reference genome datasets as well as genome-wide association studies in diverse populations are needed to address this issue. Here we describe the pilot phase of the GenomeAsia 100K Project. This includes a whole-genome sequencing reference dataset from 1,739 individuals of 219 population groups and 64 countries across Asia. We catalogue genetic variation, population structure, disease associations and founder effects. We also explore the use of this dataset in imputation, to facilitate genetic studies in populations across Asia and worldwide., Using whole-genome sequencing data from 1,739 individuals, the GenomeAsia 100K Project catalogues genetic variation, population structure and disease associations to facilitate genetic studies in Asian populations and increase representation in genetics studies worldwide.

It has been argued that the evolution of plant genome size is principally unidirectional and increasing owing to the varied action of wholegenome duplications (WGDs) and mobile element proliferation 1 . However, extreme genome size reductions have been reported in the angiosperm family tree. Here we report the sequence of the 82megabase genome of the carnivorous bladderwort plant Utricularia gibba. Despite its tiny size, the U. gibba genome accommodates a typical number of genes for a plant, with the main difference from other plant genomes arising from a drastic reduction in non-genic DNA. Unexpectedly, we identified at least three rounds of WGD in U. gibba since common ancestry with tomato (Solanum) and grape (Vitis). The compressed architecture of the U. gibba genome indicates that a small fraction of intergenic DNA, with few or no active retrotransposons, is sufficient to regulate and integrate all the processes required for the development and reproduction of a complex organism. Like other carnivorous plants, Utricularia (Lentibulariaceae) species derive nitrogen and phosphorus supplements by trapping and digesting prey organisms 2,3 . Lentibulariaceae are asterid angiosperms closely related to the model plants snapdragon (Antirrhinum) and monkey

In 1994, two independent groups extracted DNA from several Pleistocene epoch mammoths and noted differences among individual specimens. Subsequently, DNA sequences have been published for a number of extinct species. However, such ancient DNA is often fragmented and damaged, and studies to date have typically focused on short mitochondrial sequences, never yielding more than a fraction of a per cent of any nuclear genome. Here we describe 4.17 billion bases (Gb) of sequence from several mammoth specimens, 3.3 billion (80%) of which are from the woolly mammoth (Mammuthus primigenius) genome and thus comprise an extensive set of genome-wide sequence from an extinct species. Our data support earlier reports that elephantid genomes exceed 4 Gb. The estimated divergence rate between mammoth and African elephant is half of that between human and chimpanzee. The observed number of nucleotide differences between two particular mammoths was approximately one-eighth of that between one of them and the African elephant, corresponding to a separation between the mammoths of 1.5-2.0 Myr. The estimated probability that orthologous elephant and mammoth amino acids differ is 0.002, corresponding to about one residue per protein. Differences were discovered between mammoth and African elephant in amino-acid positions that are otherwise invariant over several billion years of combined mammalian evolution. This study shows that nuclear genome sequencing of extinct species can reveal population differences not evident from the fossil record, and perhaps even discover genetic factors that affect extinction.

The nucleosome is the fundamental building block of eukaryotic chromosomes. Access to genetic information encoded in chromosomes is dependent on the position of nucleosomes along the DNA. Alternative locations just a few nucleotides apart can have profound effects on gene expression. Yet the nucleosomal context in which chromosomal and gene regulatory elements reside remains ill-defined on a genomic scale. Here we sequence the DNA of 322,000 individual Saccharomyces cerevisiae nucleosomes, containing the histone variant H2A.Z, to provide a comprehensive map of H2A.Z nucleosomes in functionally important regions. With a median 4-base-pair resolution, we identify new and established signatures of nucleosome positioning. A single predominant rotational setting and multiple translational settings are evident. Chromosomal elements, ranging from telomeres to centromeres and transcriptional units, are found to possess characteristic nucleosomal architecture that may be important for their function. Promoter regulatory elements, including transcription factor binding sites and transcriptional start sites, show topological relationships with nucleosomes, such that transcription factor binding sites tend to be rotationally exposed on the nucleosome surface near its border. Transcriptional start sites tended to reside about one helical turn inside the nucleosome border. These findings reveal an intimate relationship between chromatin architecture and the underlying DNA sequence it regulates.

Ammonia oxidation is the first step in nitrification, a key process in the global nitrogen cycle that results in the formation of nitrate through microbial activity. The increase in nitrate availability in soils is important for plant nutrition, but it also has considerable impact on groundwater pollution owing to leaching. Here we show that archaeal ammonia oxidizers are more abundant in soils than their well-known bacterial counterparts. We investigated the abundance of the gene encoding a subunit of the key enzyme ammonia monooxygenase (amoA) in 12 pristine and agricultural soils of three climatic zones. amoA gene copies of Crenarchaeota (Archaea) were up to 3,000-fold more abundant than bacterial amoA genes. High amounts of crenarchaeota-specific lipids, including crenarchaeol, correlated with the abundance of archaeal amoA gene copies. Furthermore, reverse transcription quantitative PCR studies and complementary DNA analysis using novel cloning-independent pyrosequencing technology demonstrated the activity of the archaea in situ and supported the numerical dominance of archaeal over bacterial ammonia oxidizers. Our results indicate that crenarchaeota may be the most abundant ammonia-oxidizing organisms in soil ecosystems on Earth.

Hair cells have highly organized bundles of apical projections, or stereocilia, that are deflected by sound and movement. Displacement of stereocilia stretches linkages at the tips of stereocilia that are thought to gate mechanosensory channels1. To identify the molecular machinery that mediates mechanotransduction in hair cells, zebrafish mutants were identified with defects in balance and hearing2. In sputnik mutants, stereociliary bundles are splayed to various degrees, with individuals displaying reduced or absent mechanotransduction3,4. Here we show that the defects in sputnik mutants are caused by mutations in cadherin 23 (cdh23). Mutations in Cdh23 also cause deafness and vestibular defects in mice and humans5,6,7,8,9, and the protein is present in hair bundles10,11. We show that zebrafish Cdh23 protein is concentrated near the tips of hair bundles, and that tip links are absent in homozygous sputniktc317e larvae. Moreover, tip links are absent in larvae carrying weak alleles of cdh23 that affect mechanotransduction but not hair bundle integrity. We conclude that Cdh23 is an essential tip link component required for hair-cell mechanotransduction.

The genome of the lower eukaryote Dictyostelium discoideum comprises six chromosomes. Here we report the sequence of the largest, chromosome 2, which at 8 megabases (Mb) represents about 25% of the genome. Despite an A + T content of nearly 80%, the chromosome codes for 2,799 predicted protein coding genes and 73 transfer RNA genes. This gene density, about 1 gene per 2.6 kilobases (kb), is surpassed only by Saccharomyces cerevisiae (one per 2 kb) and is similar to that of Schizosaccharomyces pombe (one per 2.5 kb). If we assume that the other chromosomes have a similar gene density, we can expect around 11,000 genes in the D. discoideum genome. A significant number of the genes show higher similarities to genes of vertebrates than to those of other fully sequenced eukaryotes. This analysis strengthens the view that the evolutionary position of D. discoideum is located before the branching of metazoa and fungi but after the divergence of the plant kingdom, placing it close to the base of metazoan evolution.

We have used surface plasmon resonance biosensor technology to monitor the assembly and dynamics of a signal transduction complex which controls chemotaxis in Escherichia coli. A quaternary complex formed which consisted of the response regulator CheY, the histidine protein kinase CheA, a coupling protein CheW and a membrane-bound chemoreceptor Tar. Using various experimental conditions and mutant proteins, we have shown that the complex dissociates under conditions that favour phosphorylation of CheY. Direct physical analysis of interactions among proteins in this signal transduction pathway provides evidence for a previously unrecognized binding interaction between the kinase and its substrate. This interaction may be important for enhancing substrate specificity and preventing 'crosstalk' with other systems. The approach is generally applicable to furthering our understanding of how signalling complexes transduce intracellular messages.

Whole-genome duplication (WGD), or polyploidy, followed by gene loss and diploidization has long been recognized as an important evolutionary force in animals, fungi and other organisms, especially plants. The success of angiosperms has been attributed, in part, to innovations associated with gene or whole-genome duplications, but evidence for proposed ancient genome duplications pre-dating the divergence of monocots and eudicots remains equivocal in analyses of conserved gene order. Here we use comprehensive phylogenomic analyses of sequenced plant genomes and more than 12.6 million new expressed-sequence-tag sequences from phylogenetically pivotal lineages to elucidate two groups of ancient gene duplications-one in the common ancestor of extant seed plants and the other in the common ancestor of extant angiosperms. Gene duplication events were intensely concentrated around 319 and 192 million years ago, implicating two WGDs in ancestral lineages shortly before the diversification of extant seed plants and extant angiosperms, respectively. Significantly, these ancestral WGDs resulted in the diversification of regulatory genes important to seed and flower development, suggesting that they were involved in major innovations that ultimately contributed to the rise and eventual dominance of seed plants and angiosperms.

The complete genome sequences of an indigenous hunter-gatherer from Namibia's Kalahari Desert and of a Bantu from South Africa are presented in this issue, together with protein-coding regions from three other hunter-gatherer groups from the Kalahari. Analysis of genetic variance in what is probably the oldest known modern human lineage will contribute to understanding human diversity, and facilitate the inclusion of southern Africans in medical genomics research projects. Initial observations from the data include the fact that the Bushmen seem more different from each other, in terms of nucleotide substitutions, than typical Asians and Europeans. More speculatively, variants between these genomes and the existing data sets may point to genetic adaptations for an agricultural lifestyle. Until now, fully sequenced human genomes of the indigenous hunter-gatherer peoples of southern Africa have been limited to recently diverged populations. The complete genome sequences of an indigenous hunter-gatherer from the Kalahari Desert and of a Bantu from southern Africa are now presented. The extent of whole-genome and exome diversity is characterized; the observed genomic differences may help to pinpoint genetic adaptations to an agricultural lifestyle. The genetic structure of the indigenous hunter-gatherer peoples of southern Africa, the oldest known lineage of modern human, is important for understanding human diversity. Studies based on mitochondrial1 and small sets of nuclear markers2 have shown that these hunter-gatherers, known as Khoisan, San, or Bushmen, are genetically divergent from other humans1,3. However, until now, fully sequenced human genomes have been limited to recently diverged populations4,5,6,7,8. Here we present the complete genome sequences of an indigenous hunter-gatherer from the Kalahari Desert and a Bantu from southern Africa, as well as protein-coding regions from an additional three hunter-gatherers from disparate regions of the Kalahari. We characterize the extent of whole-genome and exome diversity among the five men, reporting 1.3 million novel DNA differences genome-wide, including 13,146 novel amino acid variants. In terms of nucleotide substitutions, the Bushmen seem to be, on average, more different from each other than, for example, a European and an Asian. Observed genomic differences between the hunter-gatherers and others may help to pinpoint genetic adaptations to an agricultural lifestyle. Adding the described variants to current databases will facilitate inclusion of southern Africans in medical research efforts, particularly when family and medical histories can be correlated with genome-wide data.

Comparative genomics of nucleosome positions provides a powerful means for understanding how the organization of chromatin and the transcription machinery co-evolve. Here we produce a high-resolution reference map of H2A.Z and bulk nucleosome locations across the genome of the fly Drosophila melanogaster and compare it to that from the yeast Saccharomyces cerevisiae. Like Saccharomyces, Drosophila nucleosomes are organized around active transcription start sites in a canonical -1, nucleosome-free region, +1 arrangement. However, Drosophila does not incorporate H2A.Z into the -1 nucleosome and does not bury its transcriptional start site in the +1 nucleosome. At thousands of genes, RNA polymerase II engages the +1 nucleosome and pauses. How the transcription initiation machinery contends with the +1 nucleosome seems to be fundamentally different across major eukaryotic lines.

Nature 496, 498–503 (2013); doi:10.1038/nature12111 In this Letter, five authors were inadvertently omitted: Sharmin Begum and Christine Lloyd from the Wellcome Trust Sanger Institute, and Christa Lanz, Gunter Raddatz and Stephan C. Schuster from the Max Planck Institute for Developmental Biology. David Elliot was incorrectly listed as David Eliot, Beverley Mortimore was incorrectly listed as Beverly Mortimer, and James D.