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Brain-derived neurotrophic factor (BDNF) promotes neuronal differentiation and survival and is implicated in the pathogenesis of many neurological disorders. Here, we identified a novel intergenic enhancer located 170 kb from the Bdnf gene, which promotes the expression of Bdnf transcript variants during mouse neuronal differentiation and activity. Following Bdnf activation, enhancer-promoter contacts increase, and the region moves away from the repressive nuclear periphery. Bdnf enhancer activity is necessary for neuronal clustering and dendritogenesis in vitro, and for cortical development in vivo. Our findings provide the first evidence of a regulatory mechanism whereby the activation of a distal enhancer promotes Bdnf expression during brain development.

Brain-derived neurotrophic factor (BDNF) promotes neuronal differentiation and survival and is implicated in the pathogenesis of many neurological disorders. Here, we identified a novel intergenic enhancer located 170 kb from the

Genome architecture plays a critical role in regulating the expression of genes that are essential for nervous system development. During neuronal differentiation, spatially and temporally regulated transcription allows neuronal migration, the growth of dendrites and axons, and at later stages, synaptic formation and the establishment of neuronal circuitry. Genome topology and relocation of gene loci within the nucleus are now regarded as key factors that contribute to transcriptional regulation. Here, we review recent work supporting the hypothesis that the dynamic organization of chromatin within the nucleus impacts gene activation in response to extrinsic signalling and during neuronal differentiation. The consequences of disruption of the genome architecture on neuronal health will be also discussed.

Transcriptional enhancers enable exquisite spatiotemporal control of gene expression in metazoans. Enrichment of monomethylation of histone H3 lysine 4 (H3K4me1) is a major chromatin signature of transcriptional enhancers. Lysine (K)-specific demethylase 1A (KDM1A, also known as LSD1), an H3K4me2/me1 demethylase, inactivates stem-cell enhancers during the differentiation of mouse embryonic stem cells (mESCs). However, its role in undifferentiated mESCs remains obscure. Here, we show that KDM1A actively maintains the optimal enhancer status in both undifferentiated and lineage-committed cells. KDM1A occupies a majority of enhancers in undifferentiated mESCs. KDM1A levels at enhancers exhibit clear positive correlations with its substrate H3K4me2, H3K27ac, and transcription at enhancers. In Kdm1a-deficient mESCs, a large fraction of these enhancers gains additional H3K4 methylation, which is accompanied by increases in H3K27 acetylation and increased expression of both enhancer RNAs (eRNAs) and target genes. In postmitotic neurons, loss of KDM1A leads to premature activation of neuronal activity-dependent enhancers and genes. Taken together, these results suggest that KDM1A is a versatile regulator of enhancers and acts as a rheostat to maintain optimal enhancer activity by counterbalancing H3K4 methylation at enhancers.

Summary: Mutations in a number of chromatin modifiers are associated with human neurological disorders. KDM5C, a histone H3 lysine 4 di- and tri-methyl (H3K4me2/3)-specific demethylase, is frequently mutated in X-linked intellectual disability (XLID) patients. Here, we report that disruption of the mouse Kdm5c gene recapitulates adaptive and cognitive abnormalities observed in XLID, including impaired social behavior, memory deficits, and aggression. Kdm5c-knockout brains exhibit abnormal dendritic arborization, spine anomalies, and altered transcriptomes. In neurons, Kdm5c is recruited to promoters that harbor CpG islands decorated with high levels of H3K4me3, where it fine-tunes H3K4me3 levels. Kdm5c predominantly represses these genes, which include members of key pathways that regulate the development and function of neuronal circuitries. In summary, our mouse behavioral data strongly suggest that KDM5C mutations are causal to XLID. Furthermore, our findings suggest that loss of KDM5C function may impact gene expression in multiple regulatory pathways relevant to the clinical phenotypes. : In this study, Iwase et al. characterize Kdm5c-knockout mice to model an important class of intellectual disability. Kdm5c-knockout mice show limited learning, heightened aggression, and dendritic spine defects. Kdm5c is a histone demethylase, and the authors identify altered transcriptional profiles in Kdm5c-knockout brains and investigate the molecular changes in neurons.

Mutations in KDM5C are an important cause of X-linked intellectual disability in males. KDM5C encodes a histone demethylase, suggesting that alterations in chromatin landscape may contribute to disease. We used primary patient cells and biochemical approaches to investigate the effects of patient mutations on KDM5C expression, stability and catalytic activity. We report and characterize a novel nonsense mutation, c.3223delG (p.V1075Yfs*2), which leads to loss of KDM5C protein. We also characterize two KDM5C missense mutations, c.1439C>T (p.P480L) and c.1204G>T (p.D402Y) that are compatible with protein production, but compromise stability and enzymatic activity. Finally, we demonstrate that a c.2T>C mutation in the translation initiation codon of KDM5C results in translation re-start and production of a N-terminally truncated protein (p.M1_E165del) that is unstable and lacks detectable demethylase activity. Patient fibroblasts do not show global changes in histone methylation but we identify several up-regulated genes, suggesting local changes in chromatin conformation and gene expression. This thorough examination of KDM5C patient mutations demonstrates the utility of examining the molecular consequences of patient mutations on several levels, ranging from enzyme production to catalytic activity, when assessing the functional outcomes of intellectual disability mutations.

Human induced pluripotent stem cells (hiPSCs1–3) are useful in disease modeling and drug discovery, and they promise to provide a new generation of cell-based therapeutics. To date there has been no systematic evaluation of the most widely used techniques for generating integration-free hiPSCs. Here we compare Sendai-viral (SeV)4, episomal (Epi)5 and mRNA transfection mRNA6 methods using a number of criteria. All methods generated high-quality hiPSCs, but significant differences existed in aneuploidy rates, reprogramming efficiency, reliability and workload. We discuss the advantages and shortcomings of each approach, and present and review the results of a survey of a large number of human reprogramming laboratories on their independent experiences and preferences. Our analysis provides a valuable resource to inform the use of specific reprogramming methods for different laboratories and different applications, including clinical translation.

Transcriptional enhancers enable exquisite spatiotemporal control of gene expression in metazoans. Enrichment of mono-methylation of histone H3 lysine 4 (H3K4me1) is a major chromatin signature that distinguishes enhancers from gene promoters. Lysine Specific Demethylase 1 (LSD1, aka KDM1A), an enzyme specific for demethylating H3K4me2/me1, has been shown to “decommission” stem cell enhancers during the differentiation of mouse embryonic stem cells (mESC). However, the roles of LSD1 in undifferentiated mESC remain obscure. Here, we show that LSD1 occupies a large fraction of enhancers (63%) that are primed with binding of transcription factors (TFs) and H3K4me1 in mESC. In contrast, LSD1 is largely absent at latent enhancers, which are not yet primed by TF binding. Unexpectedly, LSD1 levels at enhancers exhibited a clear positive correlation with its substrate, H3K4me2 and enhancer activity. These enhancers gain additional H3K4 methylation upon the loss of LSD1 in mESC. The aberrant increase in H3K4me at enhancers was accompanied with increases in enhancer H3K27 acetylation and expression of enhancer RNAs (eRNAs) and their target genes. In post-mitotic neurons, loss of LSD1 resulted in premature activation of enhancers and genes that are normally induced after neuronal activation. These results demonstrate that LSD1 is a versatile suppressor of primed enhancers, and is involved in homeostasis of enhancer activity.

Epigenetic control of gene expression programs is essential for normal organismal development and cellular function. Abrogation of epigenetic regulation is seen in many human diseases, including cancer and neuropsychiatric disorders, where it can affect disease etiology and progression. Abnormal epigenetic profiles can serve as biomarkers of disease states and predictors of disease outcomes. Therefore, epigenetics is a key area of clinical investigation in diagnosis, prognosis, and treatment. In this review, we give an overarching view of epigenetic mechanisms of human disease. Genetic mutations in genes that encode chromatin regulators can cause monogenic disease or are incriminated in polygenic, multifactorial diseases. Environmental stresses can also impact directly on chromatin regulation, and these changes can increase the risk of, or directly cause, disease. Finally, emerging evidence suggests that exposure to environmental stresses in older generations may predispose subsequent generations to disease in a manner that involves the transgenerational inheritance of epigenetic information.

Polycomb-repressed genes are marked by H3K9me3 and H3K27me3 in pluripotent ES cells, but the effects of this combination are altered by H3S10 phosphorylation in differentiated cells. Acquisition of H3K9me3/S10ph at Polycomb-target genes during differentiation reduces binding of Ezh1 and paused RNA Pol II and affects poising of repressed genes., Methylated histones H3K9 and H3K27 are canonical epigenetic silencing modifications in metazoan organisms, but the relationship between the two modifications has not been well characterized. H3K9me3 coexists with H3K27me3 in pluripotent and differentiated cells. However, we find that the functioning of H3K9me3 is altered by H3S10 phosphorylation in differentiated postmitotic osteoblasts and cycling B cells. Deposition of H3K9me3/S10ph at silent genes is partially mediated by the mitogen- and stress-activated kinases (MSK1/2) and the Aurora B kinase. Acquisition of H3K9me3/S10ph during differentiation correlates with loss of paused S5 phosphorylated RNA polymerase II, which is present on Polycomb-regulated genes in embryonic stem cells. Reduction of the levels of H3K9me3/S10ph by kinase inhibition results in increased binding of RNAPIIS5ph and the H3K27 methyltransferase Ezh1 at silent promoters. Our results provide evidence of a novel developmentally regulated methyl-phospho switch that modulates Polycomb regulation in differentiated cells and stabilizes repressed states.

Dynamic post-translational modification of RNA polymerase II (RNAPII) coordinates the co-transcriptional recruitment of enzymatic complexes that regulate chromatin states and processing of nascent RNA. Extensive phosphorylation of serine residues at the largest RNAPII subunit occurs at its structurally-disordered C-terminal domain (CTD), which is composed of multiple heptapeptide repeats with consensus sequence Y1-S2-P3-T4-S5-P6-S7. Serine-5 and Serine-7 phosphorylation mark transcription initiation, whereas Serine-2 phosphorylation coincides with productive elongation. In vertebrates, the CTD has eight non-canonical substitutions of Serine-7 into Lysine-7, which can be acetylated (K7ac). Here, we describe mono- and di-methylation of CTD Lysine-7 residues (K7me1 and K7me2). K7me1 and K7me2 are observed during the earliest transcription stages and precede or accompany Serine-5 and Serine-7 phosphorylation. In contrast, K7ac is associated with RNAPII elongation, Serine-2 phosphorylation and mRNA expression. We identify an unexpected balance between RNAPII K7 methylation and acetylation at gene promoters, which fine-tunes gene expression levels. DOI: http://dx.doi.org/10.7554/eLife.11215.001, eLife digest Genes are sections of DNA that encode the instructions to make proteins. When a gene is switched on, the section of DNA is copied to make molecules of messenger ribonucleic acid (RNA) in a process called transcription. These messenger RNAs are then used as templates for protein production. In animals, plants and other eukaryotic organisms, an enzyme called RNA polymerase II is responsible for making messenger RNA molecules during transcription. This enzyme is made up of several proteins, the largest of which contains a long tail, called the carboxy-terminal domain. This domain is crucial for transcription because it serves as a landing platform for other enzymes that help to make the RNA molecules. The carboxy-terminal domain contains multiple repeats of a string of seven amino acids (the building blocks of proteins). Normally, each repeat contains three amino acids called serines. However, in humans and other mammals, one of these serines is often substituted with another amino acid called lysine instead. This lysine (referred to as Lysine-7) was known to be modified by the addition of a chemical group called an 'acetyl' tag, but it was not clear how this tag affected transcription. Dias, Rito, Torlai Triglia et al. carried out an in-depth study into how Lysine-7 is modified in mouse cells, and what effects these modifications have on transcription. The experiments show that Lysine-7 can also be modified by the addition of a different chemical group, called a 'methyl' tag. This new modification is also found in flies, worms and human cells, which suggests that it is generally important for transcription. Next, Dias, Rito, Torlai Triglia et al. found that in mouse stem cells, methyl tags are added to Lysine-7 during the earliest steps of transcription, before the acetyl tags are added. Further experiments show that a balance between the addition of methyl tags and acetyl tags to Lysine-7 fine-tunes the activity of RNA polymerase II. These findings add to our understanding of how cells control the activity of RNA polymerase II at different genes. Future challenges are to find out which enzymes are responsible for adding and removing these chemical tags, and how the balance between the methyl and acetyl modifications is controlled. DOI: http://dx.doi.org/10.7554/eLife.11215.002

Polycomb proteins maintain cell identity by repressing the expression of developmental regulators specific for other cell types. Polycomb repressive complex-2 (PRC2) catalyzes trimethylation of histone H3 lysine-27 (H3K27me3). Although repressed, PRC2 targets are generally associated with the transcriptional initiation marker H3K4me3, but the significance of this remains unclear. Here, we identify a class of short RNAs, approximately 50-200 nucleotides in length, transcribed from the 5' end of polycomb target genes in primary T cells and embryonic stem cells. Short RNA transcription is associated with RNA polymerase II and H3K4me3, occurs in the absence of mRNA transcription, and is independent of polycomb activity. Short RNAs form stem-loop structures resembling PRC2 binding sites in Xist, interact with PRC2 through SUZ12, cause gene repression in cis, and are depleted from polycomb target genes activated during cell differentiation. We propose that short RNAs play a role in the association of PRC2 with its target genes.

Polycomb Repressor Complexes (PRCs) are important regulators of embryogenesis. In embryonic stem (ES) cells many genes that regulate subsequent stages in development are enriched at their promoters for PRC1, PRC2 and Ser 5-phosphorylated RNA Polymerase II (RNAP), and contain domains of 'bivalent' chromatin (enriched for H3K4me3; histone H3 di- or trimethylated at Lys 4 and H3K27me3; histone H3 trimethylated at Lys 27). Loss of individual PRC components in ES cells can lead to gene de-repression and to unscheduled differentiation. Here we show that Jarid2 is a novel subunit of PRC2 that is required for the co-recruitment of PRC1 and RNAP to genes that regulate development in ES cells. Jarid2-deficient ES cells showed reduced H3K4me2/me3 and H3K27me3 marking and PRC1/PRC2 recruitment, and did not efficiently establish Ser 5-phosporylated RNAP at target genes. ES cells lacking Jarid2, in contrast to previously characterized PRC1 and PRC2 mutants, did not inappropriately express PRC2 target genes. Instead, they show a severely compromised capacity for successful differentiation towards neural or mesodermal fates and failed to correctly initiate lineage-specific gene expression in vitro. Collectively, these data indicate that transcriptional priming of bivalent genes in pluripotent ES cells is Jarid2-dependent, and suggests that priming is critical for subsequent multi-lineage differentiation.

8 páginas, 5 figuras -- PAGS nros. 1428-1435, Changes in phosphorylation of the carboxy-terminal domain (CTD) of RNA polymerase II (RNAP) are associated with transcription initiation, elongation and termination1, 2, 3. Sites of active transcription are generally characterized by hyperphosphorylated RNAP, particularly at Ser 2 residues, whereas inactive or poised genes may lack RNAP or may bind Ser 5-phosphorylated RNAP at promoter proximal regions. Recent studies have demonstrated that silent developmental regulator genes have an unusual histone modification profile in ES cells, being simultaneously marked with Polycomb repressor-mediated histone H3K27 methylation, and marks normally associated with gene activity4, 5. Contrary to the prevailing view, we show here that this important subset of developmental regulator genes, termed bivalent genes, assemble RNAP complexes phosphorylated on Ser 5 and are transcribed at low levels. We provide evidence that this poised RNAP configuration is enforced by Polycomb Repressor Complex (PRC)-mediated ubiquitination of H2A, as conditional deletion of Ring1A and Ring1B leads to the sequential loss of ubiquitination of H2A, release of poised RNAP, and subsequent gene de-repression. These observations provide an insight into the molecular mechanisms that allow ES cells to self-renew and yet retain the ability to generate multiple lineage outcomes

In developed countries, the increasing incidence of obesity is a serious health problem. Leptin exposure in the perinatal period affects long-term regulation of appetite and energy expenditure, but control of leptin production in utero is unclear. This study investigated perirenal adipose tissue (PAT) and placental leptin expression in ovine fetuses during late gestation and after manipulation of plasma glucocorticoid and thyroid hormone concentrations. Between 130 and 144 d of gestation (term at 145 +/- 2 d), plasma leptin and PAT leptin mRNA levels increased in association with increments in plasma cortisol and T(3). Fetal adrenalectomy prevented these developmental changes, and exposure of intact 130 d fetuses to glucocorticoids, by cortisol infusion or maternal dexamethasone treatment, caused premature elevations in plasma leptin and PAT leptin gene expression. Fetal thyroidectomy increased plasma leptin and PAT leptin mRNA abundance, whereas intravenous T(3) infusion to intact 130 d fetuses had no effect on circulating or PAT leptin. Leptin mRNA expression was low in the ovine placenta. Therefore, in the sheep fetus, PAT appears to be a primary source of leptin in the circulation, and leptin gene expression is regulated by both glucocorticoids and thyroid hormones. Developmental changes in circulating and PAT leptin may mediate the maturational effects of cortisol in utero and have long-term consequences for appetite regulation and the development of obesity.

Intellectual disability (ID) is defined as limitations in both mental capacity and adaptive behaviour, and affects 2–3% of the population worldwide. A subset of ID, thought to be 5–10% of ID in males, is caused by mutations on the X chromosome (X-linked intellectual disability; XLID). Improvements in sequencing technologies have enabled the association of numerous genetic variants with ID, but the underlying etiology remains poorly understood, and diagnosis and treatment remain limited. Mutations in KDM5C (also known as JARID1C and SMCX) were first found in XLID patients in 2005 (Jensen et al., 2005). Additional KDM5C mutations were subsequently identified and they are now thought to account for 1–4% of X-linked ID. This is a substantial proportion; in comparison, Fragile-X syndrome is the most common cause of XLID and accounts for less than 10%. KDM5C-linked ID patients (OMIM 300534) often display short stature (~ 60% patients) and aggressive behaviour (~ 30% patients) in addition to mild to severe ID. KDM5C encodes a histone demethylase specific for histone 3 lysine 4 di- and tri-methylation (H3K4me2/3; Iwase et al., 2007). Histone proteins organize the genome, with DNA wrapping around histone octamers to form the basic unit of chromatin. Post-translational modification of histones influences chromosome compaction and provides binding sites for specific proteins, thereby regulating nuclear processes. Distinct histone modifications correlate with different transcriptional states; the KDM5C target H3K4me3 marks active promoters. Patient KDM5C mutations lower protein levels through nonsense-mediated decay or diminished protein stability, and missense mutations reduce demethylase activity (Brookes et al., 2015). This suggests a loss-of-function disease mechanism, but the cellular and molecular changes are not fully understood. In a recent study, Yang Shi and colleagues illuminated KDM5C-linked ID through generating and characterising a Kdm5c-knockout mouse (Iwase et al., 2016). Importantly, behavioural tests confirm that the mouse is a good model for the disorder, with Kdm5c-knockout mice showing heightened aggression, reduced anxiety, social aversion, and defects in learning and memory. The gross architecture of the brain was unaffected in Kdm5c-knockout mice, but abnormal neuronal morphology was noted in specific regions related to aggression (the basolateral amygala; BLA) and learning (BLA and cortex). Dendritic spine density was affected in both of these regions, whilst dendritic arborisation was reduced in the BLA (Fig. 1). Defects in dendritic branching and spine morphology have been identified in human post-mortem samples of different neurological disorders (Kulkarni and Firestein, 2012), suggesting that these deficits may be a morphological correlate of KDM5C-linked ID. Fig. 1 Model for how mutations in chromatin regulator genes cause disease, exemplified by KDM5C mutations. Mutations in chromatin regulator genes affect protein level or activity, such as reduced histone demethylase (HDM) activity of mutant KDM5C. This results ... To understand how loss of a histone demethylase results in the cellular defects observed, the authors examined genome-wide changes in gene expression in Kdm5c-knockout amygdala and cortex (Iwase et al., 2016). Multiple pathways were misregulated, including pathways important for neurological development and function. Exploration of the contribution of each altered gene/pathway to the behavioural phenotypes should provide insight into potential therapeutic targets for patients. Interestingly, in addition to influencing transcription, KDM5C has been shown to regulate DNA replication (Rondinelli et al., 2015). Although neurons are post-mitotic, this could have important implications during development, when ID is thought to arise. To explore the mechanisms of Kdm5c transcriptional regulation, Iwase et al. used primary neuronal cultures from wildtype and Kdm5c-KO littermates (Iwase et al., 2016). Kdm5c binding sites across the genome were enriched for CpG islands and high levels of H3K4me3. This finding is consistent with a recent study showing that Drosophila Lid, the Kdm5 family ortholog, recognises H3K4me2/3 through its PHD (plant homeodomain) finger, and co-localises with the mark genome-wide (Liu and Secombe, 2015). Intriguingly, only the Kdm5c-bound genes with the lowest expression levels show significant expression changes in Kdm5c-knockout neurons (Iwase et al., 2016). Chromatin modifiers are often postulated to ‘fine-tune’ expression, and this may explain why robustly transcribed genes show little alteration following its removal. Genes with altered expression levels in Kdm5c-knockout neurons predominantly show up-regulation and enhanced H3K4me3, in keeping with Kdm5c acting as a repressor through removal of an active chromatin modification (Fig. 1). A previous study of Kdm5c-knockout embryonic stem cells similarly found that Kdm5c acts at promoters to repress genes, but also suggested that Kdm5c is able to activate genes through the same demethylase activity at enhancers (Outchkourov et al., 2013). It remains to be seen whether enhancer regulation contributes to KDM5C patient symptoms; down-regulated genes were identified in Kdm5c-knockout brain and cultured neurons (Iwase et al., 2016) but the mechanisms were not examined. One intriguing facet of KDM5C-linked XLID is that whilst the mutations are germline and therefore present in all cells, the most prominent symptoms are neurological. Changes in gene expression (Jensen et al., 2010) have also been were identified in blood samples from patients with KDM5C mutations (Jensen et al., 2010). This suggests that changes in chromatin modification may occur in many tissues without eliciting a phenotype, whereas the highly complex and more recently evolved central nervous system is susceptible. This observation is by no means unique to KDM5C mutations; germline mutations in many chromatin modifiers give rise to disorders with a neurological component. Of note, chromatin changes in more easily accessible tissues may be useful as molecular markers for diagnosis and treatment. This is exemplified in a recent study of Sotos Syndrome, a syndromic ID disorder caused by mutations in the histone methyltransferase NSD1, which determined a signature of DNA methylation in peripheral blood that could be used to diagnose sufferers (Choufani et al., 2015). Mutations in genes encoding chromatin regulators are increasingly being recognized as an important contributor to neurological disorders including ID, autism spectrum disorders and schizophrenia. Furthermore, changes to chromatin can also be instigated by the environment and may contribute to disease susceptibility and prognosis. Thus, chromatin modifications should be considered as promising biomarkers and potential therapeutic targets. Good mouse models, such as the Kdm5c-knockout mice described here (Iwase et al., 2016), provide valuable tools to advance clinical practice.

International audience; Pluripotent cells develop within the inner cell mass of blastocysts, a mosaic of cells surrounded by an extra-embryonic layer, thetrophectoderm. We show that a set of somatic lineage regulators (including Hox, Gata and Sox factors) that carry bivalent chromatin enriched in H3K27me3 and H3K4me2 are selectively targeted by Suv39h1-mediated H3K9me3 and de novo DNA methylation in extra-embryonic versus embryonic (pluripotent) lineages, as assessed both in blastocyst-derived stem cells and invivo. This stably repressed state is linked with a loss of gene priming for transcription through the exclusion of PRC1 (Ring1B) and RNA polymerase II complexes at bivalent, lineage-inappropriate genes upon trophoblast lineage commitment. Collectively, our results suggest a mutually exclusive role for Ring1B and Suv39h1 in regulating distinct chromatin states at key developmental genes and propose a novel mechanism by which lineage specification can be reinforced during early development.

The regulation of gene expression programmes is essential for the generation of diverse cell types during development and for adaptation to environmental signals. RNA polymerase II (RNAPII) transcribes genetic information and coordinates the recruitment of accessory proteins that are responsible for the establishment of active chromatin states and transcript maturation. RNAPII is post-translationally modified at active genes during transcription initiation, elongation and termination, and thereby recruits specific histone and RNA modifiers. RNAPII complexes are also located at silent genes in promoter-proximal paused configurations that provide dynamic transcriptional regulation downstream from initiation. In embryonic stem cells, silent developmental regulator genes that are repressed by Polycomb are associated with a form of RNAPII that can elongate through coding regions but that lacks the post-translational modifications that are important for coupling RNA synthesis to co-transcriptional maturation. Here, we discuss the mechanisms through which the transcription of silent genes might be dissociated from productive expression, and the sophisticated interplay between the transcriptional machinery, Polycomb repression and RNA processing.

Objective: Different emotions are to some extent associated with different ways of coping. Cognitive processes involved in determining emotional reactions may influence coping (perhaps through directing attention or generating salient information). This study explored possible appraisal-coping associations by examining whether a set of appraisal components identified in emotion theory were also associated with coping. Design: The study examined concurrent associations between appraisal components, emotional adjustment, and coping in 148 women with suspected breast disease. Method: Questionnaire measures of primary and secondary appraisal components identified in emotion theory, anxiety, depression, and coping were sent to women during the waiting period between GP referral and attendance at a ‘one-stop’ breast-disease diagnosis clinic. Results: Consistent with expectations, appraisal components were associated with both emotions and coping. Elevated anxiety was associated with appraisals of low emotion-focused coping potential; avoidance coping was associated with motivational incongruence, self-accountability, and pessimistic appraisal of emotion-focused coping potential; acceptance/resignation coping was associated with self-accountability and pessimistic appraisals of both future expectancy and emotion-focused coping potential. Conclusion: This study presents a theoretically driven approach to exploring associations between emotions and adjustment efforts. In keeping with expectations, a number of appraisal components identified in emotion theory were found to be associated with both emotion and coping.

Embryonic stem cells (ESCs) are able to self-renew and to differentiate into all somatic cell types, a property termed “pluripotency.” To maintain these remarkable properties ESCs must silence the genes responsible for differentiation, but in a manner compatible with later activation. Developmental gene silencing is dependent on the Polycomb repressor complexes (PRCs), histone modifiers whose loss in ESCs leads to differentiation. PRCrepressed genes may also be occupied by active histone modifications, and the balance of both activators and repressors was thought to provide developmental genes with the potential for subsequent activation. We previously showed that PRCrepressed genes could also be bound by RNA Polymerase II (RNAPII) and transcribed. However, the prevalence of this configuration across the ESC genome was unclear, and whether activating RNAPII and silencing PRC could bind simultaneously was not tested. This is especially pertinent considering recent discussion of the heterogeneity of ESC populations, caused by dynamic fluctuations in transcription factor levels. Furthermore, cells asynchronously cycle in culture, so a snapshot of “co-occupancy” may reflect antagonistic complexes switching on and off the chromatin at distinct time points. To elucidate the interplay between RNAPII and PRCs across the ESC genome, we generated genome-wide maps of the modifications which occur to RNAPII as it progresses through the transcription cycle. RNAPII modifications are dispensable for its enzymatic activity, per se, but play critical roles in Code breaking The RNAPII modification code in pluripotency