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To unravel the source of SARS-CoV-2 introduction and the pattern of its spreading and evolution in the United Arab Emirates, we conducted meta-transcriptome sequencing of 1067 nasopharyngeal swab samples collected between May 9th and Jun 29th, 2020 during the first peak of the local COVID-19 epidemic. We identified global clade distribution and eleven novel genetic variants that were almost absent in the rest of the world and that defined five subclades specific to the UAE viral population. Cross-settlement human-to-human transmission was related to the local business activity. Perhaps surprisingly, at least 5% of the population were co-infected by SARS-CoV-2 of multiple clades within the same host. We also discovered an enrichment of cytosine-to-uracil mutation among the viral population collected from the nasopharynx, that is different from the adenosine-to-inosine change previously reported in the bronchoalveolar lavage fluid samples and a previously unidentified upregulation of APOBEC4 expression in nasopharynx among infected patients, indicating the innate immune host response mediated by ADAR and APOBEC gene families could be tissue-specific. The genomic epidemiological and molecular biological knowledge reported here provides new insights for the SARS-CoV-2 evolution and transmission and points out future direction on host–pathogen interaction investigation.

Summary We present a global atlas of 4,728 metagenomic samples from mass-transit systems in 60 cities over 3 years, representing the first systematic, worldwide catalog of the urban microbial ecosystem. This atlas provides an annotated, geospatial profile of microbial strains, functional characteristics, antimicrobial resistance (AMR) markers, and genetic elements, including 10,928 viruses, 1,302 bacteria, 2 archaea, and 838,532 CRISPR arrays not found in reference databases. We identified 4,246 known species of urban microorganisms and a consistent set of 31 species found in 97% of samples that were distinct from human commensal organisms. Profiles of AMR genes varied widely in type and density across cities. Cities showed distinct microbial taxonomic signatures that were driven by climate and geographic differences. These results constitute a high-resolution global metagenomic atlas that enables discovery of organisms and genes, highlights potential public health and forensic applications, and provides a culture-independent view of AMR burden in cities., Graphical abstract, Highlights • Cities possess a consistent “core” set of non-human microbes • Urban microbiomes echo important features of cities and city-life • Antimicrobial resistance genes are widespread in cities • Cities contain many novel bacterial and viral species, This systematic, worldwide catalog of urban microbiomes represents a metagenomic atlas important for understanding the ecology, virulence, and antibiotic resistance of city-specific microbial communities.

To unravel the source of SARS-CoV-2 introduction and the pattern of its spreading and evolution in the United Arab Emirates, we conducted meta-transcriptome sequencing of 1,067 nasopharyngeal swab samples collected between May 9th and Jun 29th, 2020 during the first peak of the local COVID-19 epidemic. We identified global clade distribution and eleven novel genetic variants that were almost absent in the rest of the world defined five subclades specific to the UAE viral population. Cross-settlement human-to-human transmission was related to the local business activity. Perhaps surprisingly, at least 5% of the population were co-infected by SARS-CoV-2 of multiple clades within the same host. We also discovered an enrichment of cytosine-to-uracil mutation among the viral population collected from the nasopharynx, that is different from the adenosine-to-inosine change previously reported in the bronchoalveolar lavage fluid samples and a previously unidentified upregulation of APOBEC4 expression in nasopharynx among infected patients, indicating the innate immune host response mediated by ADAR and APOBEC gene families could be tissue-specific. The genomic epidemiological and molecular biological knowledge reported here provides new insights for the SARS-CoV-2 evolution and transmission and points out future direction on host-pathogen interaction investigation.

Background: The United Arab Emirates is a major business hub with substantial amount of international travel. Like many other countries, it was greatly affected by the COVID-19 pandemic since late January 2020, with recurring waves of infection. This study aimed at combining genomic and epidemiological data to unravel the source of SARS-CoV-2 introduction, transmission and evolution in the country. Methods: We performed meta-transcriptomic sequencing of 1,067 nasopharyngeal swab samples collected from qRT-PCR positive COVID-19 patients in Abu Dhabi, UAE, between May 9th and June 29th 2020. We investigated the genetic diversity and transmission dynamics of the viral population and analyzed the infection and transmission potential of novel genomic clusters. Within-host SARS-CoV-2 genetic variation was analyzed to determine the occurrence and prevalence of multiple infections. Finally, we evaluated innate host responses during the prolonged period of local infection. Findings: All globally known SARS-CoV-2 clades were identified within the UAE sequenced strains, with a higher occurrence of European and East Asian clades. We defined 5 subclades based on 11 unique genetic variants within the UAE strains, which were associated with higher viral loads (p

Breast cancer cells enter into the cell cycle following progestin exposure by the activation of signalling cascades involving a plethora of enzymes, transcription factors and co-factors that transmit the external signal from the cell membrane to chromatin, ultimately leading to a change of the gene expression program. Although many of the events within the signalling network have been described in isolation, how they globally team up to generate the final cell response is unclear. In this study we use antibody microarrays and phosphoproteomics to provide a dynamic global signalling map that reveals new key regulated proteins and links between previously known and novel pathways. Detailed analysis of the data revealed intriguing changes in protein complexes involved in nuclear structure, EMT, cell adhesion, as well as transcription factors previously not associated with breast cancer proliferation. As different post-translational modifications can mediate complex crosstalk mechanisms and massive PARylation is also rapidly induced by progestins, we provide details of important chromatin regulatory complexes containing both phosphorylated and PARylated proteins. This study contributes an important resource for the scientific community, as it identifies novel players and connections meaningful for breast cancer cell biology and potentially relevant for cancer management. (197 w)

In breast cancer cells, some topologically associating domains (TADs) behave as hormonal gene regulation units, within which gene transcription is coordinately regulated in response to steroid hormones. Here we further describe that responsive TADs contain 20- to 100-kb-long clusters of intermingled estrogen receptor (ESR1) and progesterone receptor (PGR) binding sites, hereafter called hormone-control regions (HCRs). In T47D cells, we identified more than 200 HCRs, which are frequently bound by unliganded ESR1 and PGR. These HCRs establish steady long-distance inter-TAD interactions between them and organize characteristic looping structures with promoters in their TADs even in the absence of hormones in ESR1-PGR cells. This organization is dependent on the expression of the receptors and is further dynamically modulated in response to steroid hormones. HCRs function as platforms that integrate different signals, resulting in some cases in opposite transcriptional responses to estrogens or progestins. Altogether, these results suggest that steroid hormone receptors act not only as hormone-regulated sequence-specific transcription factors but also as local and global genome organizers., Spanish Ministry of Economy and Competitiveness, ‘Centro de Excelencia Severo Ochoa 2013–2017’ and Plan Nacional (SAF2016-75006-P), as well as support of the CERCA Programme/ Generalitat de Catalunya

Estrogen (E2) and Progesterone (Pg), via their specific receptors (ER and PR respectively), are major determinants in the development and progression of endometrial malignancies. Here, we have studied how E2 and the synthetic progestin R5020 affect genomic functions in Ishikawa endometrial cancer cells. Using ChIPseq in cells exposed to the corresponding hormones, we identified cell specific binding sites for ER (ERbs) and PR (PRbs), which mostly correspond to independent sites but both adjacent to sites bound by PAX2. Analysis of long-range interactions by Hi-C showed enrichment of regions co-bound by PR and PAX2 inside TADs that contain differentially progestin-regulated genes. These regions, which we call “progestin control regions” (PgCRs), exhibit an open chromatin state prior to the exposure to the hormone. Our observations suggest that endometrial response to progestins in differentiated endometrial tumor cells results in part from binding of PR together with partner transcription factors to PgCRs, compartmentalizing hormone-independent open chromatin.

Nuclear architecture is decisive for the assembly of transcriptional responses. However, how chromosome organization is dynamically modulated to permit rapid and transient transcriptional changes in response to environmental challenges remains unclear. Here we show that hyperosmotic stress disrupts different levels of chromosome organization, ranging from A/B compartment changes to reduction in the number and insulation of topologically associating domains (TADs). Concomitantly, transcription is greatly affected, TAD borders weaken, and RNA Polymerase II runs off from hundreds of transcription end sites. Stress alters the binding profiles of architectural proteins, which explains the disappearance of local chromatin organization. These processes are dynamic, and cells rapidly reconstitute their default chromatin conformation after stress removal, uncovering an intrinsic organization. Transcription is not required for local chromatin reorganization, while compartment recovery is partially transcription-dependent. Thus, nuclear organization in mammalian cells can be rapidly modulated by environmental changes in a reversible manner. The study was supported by grants from the Spanish Ministry of Economy and Competitiveness (BFU2015-64437-P and FEDER, BFU2014-52125-REDT, and BFU2014-51672-REDC to F.P.; BFU2017-85152-P and FEDER to E.d.N.), the Catalan Government (2017 SGR 799), the Fundación Botín, and the Banco Santander through its Santander Universities Global Division to F.P. and the Unidad de Excelencia Maria de Maeztu, MDM-2014-0370. F.P. is recipient of an ICREA Acadèmia (Generalitat de Catalunya). M.B. received the support of the European Research Council (ERC Synergy Grant 4D Genome 609989) and CERCA.

Steroid hormones are key gene regulators in breast cancer cells. While estrogens stimulate cell proliferation, progestins activate a single cell cycle followed by proliferation arrest. Here, we use biochemical and genome‐wide approaches to show that progestins achieve this effect via a functional crosstalk with C/EBPα. Using ChIP‐seq, we identify around 1,000 sites where C/EBPα binding precedes and helps binding of progesterone receptor (PR) in response to hormone. These regions exhibit epigenetic marks of active enhancers, and C/EBPα maintains an open chromatin conformation that facilitates loading of ligand‐activated PR. Prior to hormone exposure, C/EBPα favors promoter–enhancer contacts that assure hormonal regulation of key genes involved in cell proliferation by facilitating binding of RAD21, YY1, and the Mediator complex. Knockdown of C/EBPα disrupts enhancer–promoter contacts and decreases the presence of these architectural proteins, highlighting its key role in 3D chromatin looping. Thus, C/EBPα fulfills a previously unknown function as a potential growth modulator in hormone‐dependent breast cancer., The experimental work was supported by grants from the Departament d'Innovació Universitat i Empresa (DIUiE), and the Spanish Ministry of Economy and Competitiveness (SAF2016‐75006P), “Centro de Excelencia Severo Ochoa 2013‐2017”, SEV‐2012‐0208 and ERC Synergy Grant “4DGenome” nr: 609989.

The emergence of jawed vertebrates (gnathostomes) from jawless vertebrates was accompanied by major morphological and physiological innovations, such as hinged jaws, paired fins and immunoglobulin-based adaptive immunity. Gnathostomes subsequently diverged into two groups, the cartilaginous fishes and the bony vertebrates. Here we report the whole-genome analysis of a cartilaginous fish, the elephant shark (Callorhinchus milii). We find that the C. milii genome is the slowest evolving of all known vertebrates, including the 'living fossil' coelacanth, and features extensive synteny conservation with tetrapod genomes, making it a good model for comparative analyses of gnathostome genomes. Our functional studies suggest that the lack of genes encoding secreted calcium-binding phosphoproteins in cartilaginous fishes explains the absence of bone in their endoskeleton. Furthermore, the adaptive immune system of cartilaginous fishes is unusual: it lacks the canonical CD4 co-receptor and most transcription factors, cytokines and cytokine receptors related to the CD4 lineage, despite the presence of polymorphic major histocompatibility complex class II molecules. It thus presents a new model for understanding the origin of adaptive immunity.

Summary How repetitive elements, epigenetic modifications, and architectural proteins interact ensuring proper genome expression remains poorly understood. Here, we report regulatory mechanisms unveiling a central role of Alu elements (AEs) and RNA polymerase III transcription factor C (TFIIIC) in structurally and functionally modulating the genome via chromatin looping and histone acetylation. Upon serum deprivation, a subset of AEs pre-marked by the activity-dependent neuroprotector homeobox Protein (ADNP) and located near cell-cycle genes recruits TFIIIC, which alters their chromatin accessibility by direct acetylation of histone H3 lysine-18 (H3K18). This facilitates the contacts of AEs with distant CTCF sites near promoter of other cell-cycle genes, which also become hyperacetylated at H3K18. These changes ensure basal transcription of cell-cycle genes and are critical for their re-activation upon serum re-exposure. Our study reveals how direct manipulation of the epigenetic state of AEs by a general transcription factor regulates 3D genome folding and expression., Graphical Abstract, Highlights • Serum starvation recruits TFIIIC at ADNP-bound Alu Elements (AEs) near Pol II genes • TFIIIC-associated histone acetylase activity acetylates H3K18 over the bound AEs • TFIIIC-bound acetylated AEs loop to contact CTCF at distal cell-cycle genes’ promoters • CTCF-TFIIIC interaction ensures rapid cell-cycle genes’ reactivation on serum exposure, Repetitive elements shape genome structure and function. Ferrari et al. find that cells respond to serum deprivation by redirecting the general transcription factor TFIIIC to acetylate ADNP-bound Alu elements in order to rewire the 3D genome architecture via CTCF looping, ultimately sustaining steady-state levels of cell-cycle-regulated gene expression.

Breast cancer prognosis and response to endocrine therapy strongly depends on the expression of the estrogen and progesterone receptors (ER and PR, respectively). Although much is known about ER&alpha, gene (ESR1) regulation after hormonal stimulation, how it is regulated in hormone-free condition is not fully understood. We used ER-/PR-positive breast cancer cells to investigate the role of PR in ESR1 regulation in the absence of hormones. We show that PR binds to the low-methylated ESR1 promoter and maintains both gene expression and DNA methylation of the ESR1 locus in hormone-deprived breast cancer cells. Depletion of PR reduces ESR1 expression, with a concomitant increase in gene promoter methylation. The high amount of methylation in the ESR1 promoter of PR-depleted cells persists after the stable re-expression of PR and inhibits PR binding to this genomic region. As a consequence, the rescue of PR expression in PR-depleted cells is insufficient to restore ESR1 expression. Consistently, DNA methylation impedes PR binding to consensus progesterone responsive elements. These findings contribute to understanding the complex crosstalk between PR and ER and suggest that the analysis of ESR1 promoter methylation in breast cancer cells can help to design more appropriate targeted therapies for breast cancer patients.

HighlightsPeptidyl arginine deiminase 2 (PADI2) citrullinates arginine1810 (cit1810) present at carboxy-terminal domain of RNA polymerase II (RNAP2-CTD).PADI2 and R1810 of RNAP2-CTD regulate transcription and proliferation of breast cancer cells.Absence of cit1810 at RNAP2-CTD leads to RNAP2 accumulation at proximal promoter regions.Cit1810 at RNAP2-CTD facilitate interaction with P-TFEb complex.SUMMARYThe post-translational modification of key residues at the carboxy-terminal domain of RNA polymerase II (RNAP2-CTD), coordinates transcription, splicing, and RNA processing by modulating its capacity to act as a landing platform for a variety of protein complexes. Here, we identify a new modification at the CTD, the deimination of arginine and its conversion to citrulline by peptidyl arginine deiminase 2 (PADI2), an enzyme that has been associated with several diseases including cancer. We show that among PADI family members, only PADI2 citrullinates R1810 (Cit1810) at repeat 31 of the CTD. Depletion of PADI2 or loss of R1810 result in accumulation of RNAP2 at transcription start sites, reduced gene expression and inhibition of cell proliferation. Cit1810 is needed for interaction with the P-TEFb (positive transcription elongation factor b) kinase complex and for its recruitment to chromatin. In this way, CTD-Cit1810 favors RNAP2 pause release and efficient transcription in breast cancer cells.

In breast cancer cells, topologically associating domains (TADs) behave as units of hormonal gene regulation with transcripts within hormone responsive TADs changing coordinately their expression in response to steroid hormones. Here we further described that responsive TADs contain 20-100 kb-long clusters of intermingled estrogen receptor (ER) and progesterone receptor (PR) binding sites, hereafter called Hormone-Control Regions (HCRs). We identified more than 200 HCRs, which are frequently bound by ER and PR even in the absence of hormones. These HCRs establish steady long-distance inter-TAD interactions between them and organize characteristic looping structures with promoters even in the absence of hormones. This organization is dependent on the expression of the receptors and is further dynamically modulated in response to steroid hormones. HCRs function as platforms integrating different signals resulting in some cases in opposite transcriptional responses to estrogens or progestins. Altogether, these results suggest that steroid hormone receptors act not only as hormone-regulated sequence-specific transcription factors, but also as local and global genome organizers.HighlightsHormone responsive TADs are organized around conserved large regulatory regions (HCRs) enriched in ER and PR.HCR contact promoters within their TADs and engaged long-range inter-TADs contacts between them.Binding of the receptors in absence of hormones maintains global HCR-HCR interactions and intra-TADs regulatory loops.HCRs can integrate the hormone signals in divergent ways leading to opposite restructuration of TADs in response to Estrogens or Progestins.

Background: Whole genome re-sequencing data from dogs and wolves are now commonly used to study how natural and artificial selection have shaped the patterns of genetic diversity. Single nucleotide polymorphisms, microsatellites and variants in mitochondrial DNA have been interrogated for links to specific phenotypes or signals of domestication. However, copy number variation (CNV), despite its increasingly recognized importance as a contributor to phenotypic diversity, has not been extensively explored in canids. Results: Here, we develop a new accurate probabilistic framework to create fine-scale genomic maps of segmental duplications (SDs), compare patterns of CNV across groups and investigate their role in the evolution of the domestic dog by using information from 34 canine genomes. Our analyses show that duplicated regions are enriched in genes and hence likely possess functional importance. We identify 86 loci with large CNV differences between dogs and wolves, enriched in genes responsible for sensory perception, immune response, metabolic processes, etc. In striking contrast to the observed loss of nucleotide diversity in domestic dogs following the population bottlenecks that occurred during domestication and breed creation, we find a similar proportion of CNV loci in dogs and wolves, suggesting that other dynamics are acting to particularly select for CNVs with potentially functional impacts. Conclusions: This work is the first comparison of genome wide CNV patterns in domestic and wild canids using whole-genome sequencing data and our findings contribute to study the impact of novel kinds of genetic changes on the evolution of the domestic dog

The positive-regulatory domain containing nine gene, PRDM9, which strongly associates with the location of recombination events in several vertebrates, is inferred to be inactive in the dog genome. Here, we address several questions regarding the control of recombination and its influence on genome evolution in dogs. First, we address whether the association between CpG islands (CGIs) and recombination hotspots is generated by lack of methylation, GC-biased gene conversion (gBGC), or both. Using a genome-wide dog single nucleotide polymorphism data set and comparisons of the dog genome with related species, we show that recombination-associated CGIs have low CpG mutation rates, and that CpG mutation rate is negatively correlated with recombination rate genome wide, indicating that nonmethylation attracts the recombination machinery. We next use a neighbor-dependent model of nucleotide substitution to disentangle the effects of CpG mutability and gBGC and analyze the effects that loss of PRDM9 has on these rates. We infer that methylation patterns have been stable during canid genome evolution, but that dog CGIs have experienced a drastic increase in substitution rate due to gBGC, consistent with increased levels of recombination in these regions. We also show that gBGC is likely to have generated many new CGIs in the dog genome, but these mostly occur away from genes, whereas the number of CGIs in gene promoter regions has not increased greatly in recent evolutionary history. Recombination has a major impact on the distribution of CGIs that are detected in the dog genome due to the interaction between methylation and gBGC. The results indicate that germline methylation patterns are the main determinant of recombination rates in the absence of PRDM9.

Despite representing an important source of genetic variation, tandem repeats (TRs) remain poorly studied due to technical difficulties. We hypothesized that TRs can operate as expression (eQTLs) and methylation (mQTLs) quantitative trait loci. To test this we analyzed the effect of variation at 4849 promoter-associated TRs, genotyped in 120 individuals, on neighboring gene expression and DNA methylation. Polymorphic promoter TRs were associated with increased variance in local gene expression and DNA methylation, suggesting functional consequences related to TR variation. We identified >100 TRs associated with expression/methylation levels of adjacent genes. These potential eQTL/mQTL TRs were enriched for overlaps with transcription factor binding and DNaseI hypersensitivity sites, providing a rationale for their effects. Moreover, we showed that most TR variants are poorly tagged by nearby single nucleotide polymorphisms (SNPs) markers, indicating that many functional TR variants are not effectively assayed by SNP-based approaches. Our study assigns biological significance to TR variations in the human genome, and suggests that a significant fraction of TR variations exert functional effects via alterations of local gene expression or epigenetics. We conclude that targeted studies that focus on genotyping TR variants are required to fully ascertain functional variation in the genome.

Eukaryotic gene regulation is associated with changes in chromatin compaction that modulate access to DNA regulatory sequences relevant for transcriptional activation or repression. Although much is known about the mechanism of chromatin remodeling in hormonal gene activation, how repression is accomplished is much less understood. Here we report that in breast cancer cells, ligand-activated progesterone receptor (PR) is directly recruited to transcriptionally repressed genes involved in cell proliferation along with the kinases ERK1/2 and MSK1. PR recruits BRG1 associated with the HP1γ-LSD1 complex repressor complex, which is further anchored via binding of HP1γ to the H3K9me3 signal deposited by SUV39H2. In contrast to what is observed during gene activation, only BRG1 and not the BAF complex is recruited to repressed promoters, likely due to local enrichment of the pioneer factor FOXA1. BRG1 participates in gene repression by interacting with H1.2, facilitating its deposition and stabilizing nucleosome positioning around the transcription start site. Our results uncover a mechanism of hormone-dependent transcriptional repression and a novel role for BRG1 in progestin regulation of breast cancer cell growth. The experimental work was supported by grants from the Departament d’Innovació Universitat i Empresa (DIUiE). We acknowledge support of the Spanish Ministry of Economy and Competitiveness (SAF2013-42497-P), “Centro de Excelencia Severo Ochoa 2013–2017”, SEV-2012-0208 and ERC Synergy Grant “4DGenome” nr 609989

Carbone, Lucia et al.-- This work is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 Unported licence., Gibbons are small arboreal apes that display an accelerated rate of evolutionary chromosomal rearrangement and occupy a key node in the primate phylogeny between Old World monkeys and great apes. Here we present the assembly and analysis of a northern white-cheeked gibbon (Nomascus leucogenys) genome. We describe the propensity for a gibbon-specific retrotransposon (LAVA) to insert into chromosome segregation genes and alter transcription by providing a premature termination site, suggesting a possible molecular mechanism for the genome plasticity of the gibbon lineage. We further show that the gibbon genera (Nomascus, Hylobates, Hoolock and Symphalangus) experienced a near-instantaneous radiation ∼5 million years ago, coincident with major geographical changes in southeast Asia that caused cycles of habitat compression and expansion. Finally, we identify signatures of positive selection in genes important for forelimb development (TBX5) and connective tissues (COL1A1) that may have been involved in the adaptation of gibbons to their arboreal habitat.

Venkatesh; Byrappa et al.-- This work is licensed under a Creative Commons Attribution- NonCommercial-Share Alike 3.0 Unported licence., The emergence of jawed vertebrates (gnathostomes) from jawless vertebrates was accompanied by major morphological and physiological innovations, such as hinged jaws, paired fins and immunoglobulin-based adaptive immunity. Gnathostomes subsequently diverged into two groups, the cartilaginous fishes and the bony vertebrates. Here we report the whole-genome analysis of a cartilaginous fish, the elephant shark (Callorhinchus milii). We find that the C. milii genome is the slowest evolving of all known vertebrates, including the 'living fossil' coelacanth, and features extensive synteny conservation with tetrapod genomes, making it a good model for comparative analyses of gnathostome genomes. Our functional studies suggest that the lack of genes encoding secreted calcium-binding phosphoproteins in cartilaginous fishes explains the absence of bone in their endoskeleton. Furthermore, the adaptive immune system of cartilaginous fishes is unusual: it lacks the canonical CD4 co-receptor and most transcription factors, cytokines and cytokine receptors related to the CD4 lineage, despite the presence of polymorphic major histocompatibility complex class II molecules. It thus presents a new model for understanding the origin of adaptive immunity. © 2014 Macmillan Publishers Limited.

[Background] Although a variety of genetic changes have been implicated in causing phenotypic differences among dogs, the role of copy number variants (CNVs) and their impact on phenotypic variation is still poorly understood. Further, very limited knowledge exists on structural variation in the gray wolf, the ancestor of the dog, or other closely related wild canids. Documenting CNVs variation in wild canids is essential to identify ancestral states and variation that may have appeared after domestication., [Results] In this work, we genotyped 1,611 dog CNVs in 23 wolf-like canids (4 purebred dogs, one dingo, 15 gray wolves, one red wolf, one coyote and one golden jackal) to identify CNVs that may have arisen after domestication. We have found an increase in GC-rich regions close to the breakpoints and around 1 kb away from them suggesting that some common motifs might be associated with the formation of CNVs. Among the CNV regions that showed the largest differentiation between dogs and wild canids we found 12 genes, nine of which are related to two known functions associated with dog domestication; growth (PDE4D, CRTC3 and NEB) and neurological function (PDE4D, EML5, ZNF500, SLC6A11, ELAVL2, RGS7 and CTSB)., [Conclusions] Our results provide insight into the evolution of structural variation in canines, where recombination is not regulated by PRDM9 due to the inactivation of this gene. We also identified genes within the most differentiated CNV regions between dogs and wolves, which could reflect selection during the domestication process., R is a postdoctoral Researcher from the JAEdoc program cofounded by European Science Foundation. IO has a predoctoral fellowship from the Basque Government (DEUI). This work has been founded by Spanish Government Grants BFU2011-28549 (to TM-B) and BFU2012-34157 (to CL-F), Andalusian Government Grant “Programa de Captación del Conocimiento para Andalucía C2A” (to CV) and EU ERC Starting Grant 260372 (to TM-B).

Tandem repeats are common in eukaryotic genomes, but due to difficulties in assaying them remain poorly studied. Here, we demonstrate the utility of Nanostring technology as a targeted approach to perform accurate measurement of tandem repeats even at extremely high copy number, and apply this technology to genotype 165 HapMap samples from three different populations and five species of non-human primates. We observed extreme variability in copy number of tandemly repeated genes, with many loci showing 5–10 fold variation in copy number among humans. Many of these loci show hallmarks of genome assembly errors, and the true copy number of many large tandem repeats is significantly under-represented even in the high quality ‘finished’ human reference assembly. Importantly, we demonstrate that most large tandem repeat variations are not tagged by nearby SNPs, and are therefore essentially invisible to SNP-based GWAS approaches. Using association analysis we identify many cis correlations of large tandem repeat variants with nearby gene expression and DNA methylation levels, indicating that variations of tandem repeat length are associated with functional effects on the local genomic environment. This includes an example where expansion of a macrosatellite repeat is associated with increased DNA methylation and suppression of nearby gene expression, suggesting a mechanism termed “repeat induced gene silencing”, which has previously been observed only in transgenic organisms. We also observed multiple signatures consistent with altered selective pressures at tandemly repeated loci, suggesting important biological functions. Our studies show that tandemly repeated loci represent a highly variable fraction of the genome that have been systematically ignored by most previous studies, copy number variation of which can exert functionally significant effects. We suggest that future studies of tandem repeat loci will lead to many novel insights into their role in modulating both genomic and phenotypic diversity., Author Summary Here we utilize Nanostring digital assays and show their utility for estimating copy number of 186 multicopy genes and tandem repeats. By analyzing patterns of single nucleotide variation around these variants, we show that copy number variation at the vast majority of tandem repeat variations is not effectively tagged by nearby SNPs, and thus standard genome-wide association studies that focus on SNPs provide little or no information about such variants. By comparing patterns of tandem repeat copy number with variation in local gene expression and DNA methylation, we also identify extensive functional effects on local genome function. This includes an example of a non-coding macrosatellite repeat, expansion of which exerts a repressive effect on a nearby gene accompanied by accumulations of local DNA methylation. Finally, comparison of diverse human populations with a number of primate genomes shows that many of these sequences have undergone extreme changes in copy number during recent human and primate evolution, and show signatures that suggest possible selective effects. Overall, we conclude that multicopy genes and macrosatellites represent a highly variable fraction of the genome with important functional effects that has been systematically ignored by previous studies.

[Background]: Modern dog breeds display traits that are either breed-specific or shared by a few breeds as a result of genetic bottlenecks during the breed creation process and artificial selection for breed standards. Selective sweeps in the genome result from strong selection and can be detected as a reduction or elimination of polymorphism in a given region of the genome., [Results]: Extended regions of homozygosity, indicative of selective sweeps, were identified in a genome-wide scan dataset of 25 Boxers from the United Kingdom genotyped at ~20,000 single-nucleotide polymorphisms (SNPs). These regions were further examined in a second dataset of Boxers collected from a different geographical location and genotyped using higher density SNP arrays (~170,000 SNPs). A selective sweep previously associated with canine brachycephaly was detected on chromosome 1. A novel selective sweep of over 8 Mb was observed on chromosome 26 in Boxer and for a shorter region in English and French bulldogs. It was absent in 171 samples from eight other dog breeds and 7 Iberian wolf samples. A region of extended increased heterozygosity on chromosome 9 overlapped with a previously reported copy number variant (CNV) which was polymorphic in multiple dog breeds., [Conclusion]: A selective sweep of more than 8 Mb on chromosome 26 was identified in the Boxer genome. This sweep is likely caused by strong artificial selection for a trait of interest and could have inadvertently led to undesired health implications for this breed. Furthermore, we provide supporting evidence for two previously described regions: a selective sweep on chromosome 1 associated with canine brachycephaly and a CNV on chromosome 9 polymorphic in multiple dog breeds., This work was funded by the European Commission (LUPA, GA-201370) and the Grant Number RR016466 from the National Center for Research Resources (NCRR), a component of the NIH and the American Kennel Club grant 0876-A.

[Background]: Diagnosis and follow up of CanL is difficult since the range of clinical signs is varied and seroprevalence is high in endemic areas. The aims of this study were: i) demonstrate the advantages of Leishmania qPCR to diagnose and control CanL and highlight its prognostic value and ii) propose guidelines for tissue selection and infection monitoring., [Findings]: This study included 710 dogs living in an endemic area of leishmaniasis. Forty percent (285/710) exhibited clinical signs consistent with CanL. Infection was detected in 36.3% (258/710) of the dogs of which 4.5% (32/710) were detected by qPCR, 16.2% (115/710) detected by ELISA and 15.6% (111/710) tested positive for both tests. Only 17.9% (127/710) of the dogs were classified sick (affected) with CanL. All symptomatic dogs with medium or high ELISA titers were qPCR-positive in blood samples. All dogs with inconclusive or low ELISA results with high or medium qPCR parasitemia values developed the disease. Seventy one percent of asymptomatic ELISA-positive dogs confirmed by qPCR (medium to high parasitemia) developed the disease. Bone marrow or lymph node aspirate should be selected to ensure the absence of the parasite in asymptomatic dogs: 100-1,000 parasites/ml in bone marrow are detectable in blood, whereas lower parasite loads are usually negative. Almost 10% of negative samples in blood were positive in conjunctival swabs., [Conclusions]: Because qPCR allows parasite quantification, it is an effective tool to confirm a diagnosis of CanL in (i) cases of inconclusive ELISA results, (ii) when the dog has not yet seroconverted, or (iii) for treatment monitoring., This work was founded by the European commission (LUPA, GA-201370).

Nature 505, 174–179 (2014); doi:10.1038/nature12826 The ranges of accession numbers JW861113–JW881738 and KA353634–KA353668 (20,661 in total) cited in this Article include 3,630 sequences that were unrelated and hence removed from the NCBI GenBank database before the analysis of the data and submission of the manuscript to Nature.

Background. Domestic cats enjoy an extensive veterinary medical surveillance which has described nearly 250 genetic diseases analogous to human disorders. Feline infectious agents offer powerful natural models of deadly human diseases, which include feline immunodeficiency virus, feline sarcoma virus and feline leukemia virus. A rich veterinary literature of feline disease pathogenesis and the demonstration of a highly conserved ancestral mammal genome organization make the cat genome annotation a highly informative resource that facilitates multifaceted research endeavors./nFindings. Here we report a preliminary annotation of the whole genome sequence of Cinnamon, a domestic cat living in Columbia (MO, USA), bisulfite sequencing of Boris, a male cat from St. Petersburg (Russia), and light 30× sequencing of Sylvester, a European wildcat progenitor of cat domestication. The annotation includes 21,865 protein-coding genes identified by a comparative approach, 217 loci of endogenous retrovirus-like elements, repetitive elements which comprise about 55.7% of the whole genome, 99,494 new SNVs, 8,355 new indels, 743,326 evolutionary constrained elements, and 3,182 microRNA homologues. The methylation sites study shows that 10.5% of cat genome cytosines are methylated. An assisted assembly of a European wildcat, Felis silvestris silvestris, was performed; variants between F. silvestris and F. catus genomes were derived and compared to F. catus./nConclusions. The presented genome annotation extends beyond earlier ones by closing gaps of sequence that were unavoidable with previous low-coverage shotgun genome sequencing. The assembly and its annotation offer an important resource for connecting the rich veterinary and natural history of cats to genome discovery. This work was supported, in part, by Russian Ministry of Science Mega-grant no.11.G34.31.0068; Stephen J. O’Brien, Principal Investigator and ERC Starting Grant (260372) and MICINN (Spain) BFU2011-28549 grants to Tomas Marques-Bonet.

Hereditary periodic fever syndromes are characterized by recurrent episodes of fever and inflammation with no known pathogenic or autoimmune cause. In humans, several genes have been implicated in this group of diseases, but the majority of cases remain unexplained. A similar periodic fever syndrome is relatively frequent in the Chinese Shar-Pei breed of dogs. In the western world, Shar-Pei have been strongly selected for a distinctive thick and heavily folded skin. In this study, a mutation affecting both these traits was identified. Using genome-wide SNP analysis of Shar-Pei and other breeds, the strongest signal of a breed-specific selective sweep was located on chromosome 13. The same region also harbored the strongest genome-wide association (GWA) signal for susceptibility to the periodic fever syndrome (praw = 2.3×10−6, pgenome = 0.01). Dense targeted resequencing revealed two partially overlapping duplications, 14.3 Kb and 16.1 Kb in size, unique to Shar-Pei and upstream of the Hyaluronic Acid Synthase 2 (HAS2) gene. HAS2 encodes the rate-limiting enzyme synthesizing hyaluronan (HA), a major component of the skin. HA is up-regulated and accumulates in the thickened skin of Shar-Pei. A high copy number of the 16.1 Kb duplication was associated with an increased expression of HAS2 as well as the periodic fever syndrome (p, This work was supported by the Swedish Research Council; FORMAS; the Swedish Research Council for Environment, Agricultural Sciences, and Spatial Planning; the Swedish Foundation for Strategic Research; in part by the Intramural Research Program of the National Institute of Arthritis and Musculoskeletal and Skin Diseases and the National Human Genome Research Institute of the National Institutes of Health; the Chinese Shar-Pei Charitable Trust and the European Commission (FP7-LUPA, GA-201370). KL-T is the recipient of a EURYI award from the European Science Foundation.

Little is known about the genetic changes that distinguish domestic cat populations from their wild progenitors. Here we describe a high-quality domestic cat reference genome assembly and comparative inferences made with other cat breeds, wildcats, and other mammals. Based upon these comparisons, we identified positively selected genes enriched for genes involved in lipid metabolism that underpin adaptations to a hypercarnivorous diet. We also found positive selection signals within genes underlying sensory processes, especially those affecting vision and hearing in the carnivore lineage. We observed an evolutionary tradeoff between functional olfactory and vomeronasal receptor gene repertoires in the cat and dog genomes, with an expansion of the feline chemosensory system for detecting pheromones at the expense of odorant detection. Genomic regions harboring signatures of natural selection that distinguish domestic cats from their wild congeners are enriched in neural crest-related genes associated with behavior and reward in mouse models, as predicted by the domestication syndrome hypothesis. Our description of a previously unidentified allele for the gloving pigmentation pattern found in the Birman breed supports the hypothesis that cat breeds experienced strong selection on specific mutations drawn from random bred populations. Collectively, these findings provide insight into how the process of domestication altered the ancestral wildcat genome and build a resource for future disease mapping and phylogenomic studies across all members of the Felidae.

[Background] Genomic studies of endangered species provide insights into their evolution and demographic history, reveal patterns of genomic erosion that might limit their viability, and offer tools for their effective conservation. The Iberian lynx (Lynx pardinus) is the most endangered felid and a unique example of a species on the brink of extinction., [Results] We generate the first annotated draft of the Iberian lynx genome and carry out genome-based analyses of lynx demography, evolution, and population genetics. We identify a series of severe population bottlenecks in the history of the Iberian lynx that predate its known demographic decline during the 20th century and have greatly impacted its genome evolution. We observe drastically reduced rates of weak-to-strong substitutions associated with GC-biased gene conversion and increased rates of fixation of transposable elements. We also find multiple signatures of genetic erosion in the two remnant Iberian lynx populations, including a high frequency of potentially deleterious variants and substitutions, as well as the lowest genome-wide genetic diversity reported so far in any species., [Conclusions] The genomic features observed in the Iberian lynx genome may hamper short- and long-term viability through reduced fitness and adaptive potential. The knowledge and resources developed in this study will boost the research on felid evolution and conservation genomics and will benefit the ongoing conservation and management of this emblematic species., The financial support for this work was provided by Banco de Santander, CSIC, and Fundación General CSIC through a “Proyectos Cero” grant. FC and BM-C were hired under the EcoGenes project funded by the European FP7 program (264125-FP7-REGPOT-2010-1) and AVl and FCa under the INB Project PT13/0001/ 0021 (ISCIII - Subdirección General de Evaluación y Fomento de la Investigación/ FEDER “Una Manera de hacer Europa”). EBD-CSIC and CRG received support from the Spanish Ministry of Economy and Competitiveness under the “Centro de Excelencia Severo Ochoa 2013-2017” program, grants SEV-2012-0262 and SEV-2012-0208. We acknowledge support of the publication fee by the CSIC Open Access Publication Support Initiative through its Unit of Information Resources for Research (URICI).

[Background]: The current disease model for leishmaniasis suggests that only a proportion of infected individuals develop clinical disease, while others are asymptomatically infected due to immune control of infection. The factors that determine whether individuals progress to clinical disease following Leishmania infection are unclear, although previous studies suggest a role for host genetics. Our hypothesis was that canine leishmaniasis is a complex disease with multiple loci responsible for the progression of the disease from Leishmania infection., [Methodology/Principal Findings]: Genome-wide association and genomic selection approaches were applied to a population-based case-control dataset of 219 dogs from a single breed (Boxer) genotyped for ∼170,000 SNPs. Firstly, we aimed to identify individual disease loci; secondly, we quantified the genetic component of the observed phenotypic variance; and thirdly, we tested whether genome-wide SNP data could accurately predict the disease., [Conclusions/Significance]: We estimated that a substantial proportion of the genome is affecting the trait and that its heritability could be as high as 60%. Using the genome-wide association approach, the strongest associations were on chromosomes 1, 4 and 20, although none of these were statistically significant at a genome-wide level and after correcting for genetic stratification and lifestyle. Amongst these associations, chromosome 4: 61.2–76.9 Mb maps to a locus that has previously been associated with host susceptibility to human and murine leishmaniasis, and genomic selection estimated markers in this region to have the greatest effect on the phenotype. We therefore propose these regions as candidates for replication studies. An important finding of this study was the significant predictive value from using the genomic information. We found that the phenotype could be predicted with an accuracy of ∼0.29 in new samples and that the affection status was correctly predicted in 60% of dogs, significantly higher than expected by chance, and with satisfactory sensitivity-specificity values (AUC = 0.63)., This work was funded by the European Commission (LUPA, GA-201370) as well as by the Consolider-Ingenio 2010 Programme CSD2007-00036 ‘‘Centre for Research in Agrigenomics’’ from the Spanish Ministry of Science and Innovation.

To unravel the source of SARS-CoV-2 introduction and the pattern of its spreading and evolution in the United Arab Emirates, we conducted meta-transcriptome sequencing of 1067 nasopharyngeal swab samples collected between May 9th and Jun 29th, 2020 during the first peak of the local COVID-19 epidemic. We identified global clade distribution and eleven novel genetic variants that were almost absent in the rest of the world and that defined five subclades specific to the UAE viral population. Cross-settlement human-to-human transmission was related to the local business activity. Perhaps surprisingly, at least 5% of the population were co-infected by SARS-CoV-2 of multiple clades within the same host. We also discovered an enrichment of cytosine-to-uracil mutation among the viral population collected from the nasopharynx, that is different from the adenosine-to-inosine change previously reported in the bronchoalveolar lavage fluid samples and a previously unidentified upregulation of APOBEC4 expression in nasopharynx among infected patients, indicating the innate immune host response mediated by ADAR and APOBEC gene families could be tissue-specific. The genomic epidemiological and molecular biological knowledge reported here provides new insights for the SARS-CoV-2 evolution and transmission and points out future direction on host-pathogen interaction investigation.