Networks of transcription factors (TFs) are thought to determine and maintain the identity of cells. Here we systematically repressed each of 100 TFs with shRNA and carried out global gene expression profiling in mouse embryonic stem (ES) cells. Unexpectedly, only the repression of a handful of TFs significantly affected transcriptomes, which changed in two directions/trajectories: one trajectory by the repression of either Pou5f1 or Sox2; the other trajectory by the repression of either Esrrb, Sall4, Nanog, or Tcfap4. The data suggest that the trajectories of gene expression change are already preconfigured by the gene regulatory network and roughly correspond to extraembryonic and embryonic fates of cell differentiation, respectively. These data also indicate the robustness of the pluripotency gene network, as the transient repression of most TFs did not alter the transcriptomes.

Human longevity and personality traits are both heritable and are consistently linked at the phenotypic level. We test the hypothesis that candidate genes influencing longevity in lower organisms are associated with variance in the five major dimensions of human personality (measured by the NEO-FFI and IPIP inventories) plus related mood states of anxiety and depression. Seventy single nucleotide polymorphisms (SNPs) in six brain expressed, longevity candidate genes (AFG3L2, FRAP1, MAT1A, MAT2A, SYNJ1 and SYNJ2) were typed in over one thousand 70-year old participants from the Lothian Birth Cohort of 1936 (LBC1936). No SNPs were associated with the personality and psychological distress traits at a Bonferroni corrected level of significance (p < 0.0002), but there was an over-representation of nominally significant (p < 0.05) SNPs in the synaptojanin-2 (SYNJ2) gene associated with agreeableness and symptoms of depression. Eight SNPs which showed nominally significant association across personality measurement instruments were tested in an extremely large replication sample of 17 106 participants. SNP rs350292, in SYNJ2, was significant: the minor allele was associated with an average decrease in NEO agreeableness scale scores of 0.25 points, and 0.67 points in the restricted analysis of elderly cohorts (most aged > 60 years). Because we selected a specific set of longevity genes based on functional genomics findings, further research on other longevity gene candidates is warranted to discover whether they are relevant candidates for personality and psychological distress traits.

PLAC1 expression, first characterized as restricted to developing placenta among normal tissues, is also found in a wide range of tumors and transformed cell lines. To understand the basis for its unusual expression profile, we have analyzed the gene structure and its mode of transcription. We find that the gene has a hitherto unique feature, with two promoters, P1 and P2, separated by 105 kb. P2 has been described before. Here we define P1 and show that it and P2 are activated by RXRα in conjunction with LXRα or LXRβ. In placenta, P2 is the preferred promoter, whereas various tumor cell lines tend to express predominantly either one or the other promoter. Furthermore, when each promoter is fused to a luciferase reporter gene and transfected into cancer cell lines, the promoter corresponding to the more active endogenous promoter is preferentially transcribed. Joint expression of activating nuclear receptors can partially account for the restricted expression of PLAC1 in placenta, and may be co-opted for preferential P1 or P2 PLAC1 expression in various tumor cells.

In embryonic Eda mutant (“Tabby”) mice, the development of one of the two major types of hair, “primary” hair fails, but other “secondary” hairs develop in normal numbers, though shorter and slightly aberrant. In Tabby mice, Shh is undetectable in skin early on, but is activated during secondary hair formation. We inferred that Shh may be involved in primary hair formation, activated normally by Eda, and also possibly in secondary hair formation, activated by an Eda-independent pathway. Varying the dosage of Shh now supports these inferences. In Shh knockout mice, mice were totally hairless: primary and secondary hair follicle germs were formed, but further progression failed. Consistent with these findings, when Shh loss was restricted to the skin, secondary hair follicle germs were initiated on time in Tabby mice, but their subsequent development (down-growth) failed. An Shh transgene expressed in Tabby skin could not restore induction of primary hair follicles, but restored normal length to the somewhat aberrant secondary hair that was formed and prolonged the anagen phase of hair cycling. Thus, Shh is required for primary and secondary hair downgrowth and full secondary hair length, but is not itself sufficient to replace Eda or make fully normal secondary hair.

Objective

Animal models and clinical studies suggest that brain-derived neurotrophic factor (BDNF) is involved in the pathophysiology of depression. We test whether serum and plasma levels of BDNF are associated with trait Neuroticism and its facets, and with state measure of depressive symptoms.

Method

In a community-based cohort (N = 2099) we measured serum and plasma BDNF concentration, administered the Revised NEO Personality Inventory (NEO-PI-R) and the Center for Epidemiologic Studies Depression Scale (CES-D). Covariates included age, sex, cigarette smoking, obesity, and antidepressant use.

Results

Serum BDNF concentrations were inversely related to Neuroticism (r = −0.074, P < 0.001), in particular the Depression facet (r = −0.08, P < 0.001). Lower BDNF concentrations were also associated with severe depressive symptoms (CES-D ≥ 28; OR = 0.906; 95%CI = 0.851–0.965). The association of serum BDNF with Neuroticism was independent of depressive symptoms, indicating that serum BDNF might represent a biological correlate of Neuroticism and not just of transient depressive states. Plasma BDNF was not associated with measures of depression.

Conclusions

Our study suggests that lower serum BDNF is associated with both a dispositional vulnerability to depression and acute depressive states in the general population.

The genetic determinants of variation in iron status are actively sought, but remain incompletely understood. Meta-analysis of two genome-wide association (GWA) studies and replication in three independent cohorts was performed to identify genetic loci associated in the general population with serum levels of iron and markers of iron status, including transferrin, ferritin, soluble transferrin receptor (sTfR) and sTfR–ferritin index. We identified and replicated a novel association of a common variant in the type-2 transferrin receptor (TFR2) gene with iron levels, with effect sizes highly consistent across samples. In addition, we identified and replicated an association between the HFE locus and ferritin and confirmed previously reported associations with the TF, TMPRSS6 and HFE genes. The five replicated variants were tested for association with expression levels of the corresponding genes in a publicly available data set of human liver samples, and nominally statistically significant expression differences by genotype were observed for all genes, although only rs3811647 in the TF gene survived the Bonferroni correction for multiple testing. In addition, we measured for the first time the effects of the common variant in TMPRSS6, rs4820268, on hepcidin mRNA in peripheral blood (n = 83 individuals) and on hepcidin levels in urine (n = 529) and observed an association in the same direction, though only borderline significant. These functional findings require confirmation in further studies with larger sample sizes, but they suggest that common variants in TMPRSS6 could modify the hepcidin-iron feedback loop in clinically unaffected individuals, thus making them more susceptible to imbalances of iron homeostasis.

Embryonic stem cells (ESCs) have remarkable properties of pluripotency and self-renewal, along with the retention of chromosomal integrity. Germ cells function as a kind of “transgenerational stem cells”, transmitting genetic information from one generation to the next. The formation of putative primordial germ cells (PGCs) and germ cells from mouse and human ESCs has, in fact, been shown, and the apparent derivation of functional mouse male gametes has also been described. Additionally investigators have successfully reprogrammed somatic nuclei into a pluripotent state by inserting them into ESCs or oocytes. This would enable the generation of ESCs genetically identical to the somatic cell donor and their use in cell therapy. However, these methodologies are still inefficient and their mechanisms poorly understood. Until full comprehension of these processes is obtained, clinical applications remain remote. Nevertheless, they represent promising tools in the future, enhancing methods of therapeutic cloning and infertility treatment.

In a community-dwelling sample (N=4,790; age range 14–94), we examined whether personality traits prospectively predicted performance on a verbal fluency task. Open, extraverted, and emotionally stable participants had better verbal fluency. At the facet level, dispositionally happy and self-disciplined participants retrieved more words; those prone to anxiety and depression and those who were deliberative retrieved fewer words. Education moderated the association between Conscientiousness and fluency such that participants with lower education performed better on the fluency task if they were also conscientious. Age was not a moderator at the domain level, indicating that the personality-fluency associations were consistent across the lifespan. A disposition towards emotional vulnerability and being less open, less happy, and undisciplined may be detrimental to cognitive performance.

Identifying the genes that influence levels of pro-inflammatory molecules can help to elucidate the mechanisms underlying this process. We first conducted a two-stage genome-wide association scan (GWAS) for the key inflammatory biomarkers Interleukin-6 (IL-6), the general measure of inflammation erythrocyte sedimentation rate (ESR), monocyte chemotactic protein-1 (MCP-1), and high-sensitivity C-reactive protein (hsCRP) in a large cohort of individuals from the founder population of Sardinia. By analysing 731,213 autosomal or X chromosome SNPs and an additional ∼1.9 million imputed variants in 4,694 individuals, we identified several SNPs associated with the selected quantitative trait loci (QTLs) and replicated all the top signals in an independent sample of 1,392 individuals from the same population. Next, to increase power to detect and resolve associations, we further genotyped the whole cohort (6,145 individuals) for 293,875 variants included on the ImmunoChip and MetaboChip custom arrays. Overall, our combined approach led to the identification of 9 genome-wide significant novel independent signals—5 of which were identified only with the custom arrays—and provided confirmatory evidence for an additional 7. Novel signals include: for IL-6, in the ABO gene (rs657152, p = 2.13×10−29); for ESR, at the HBB (rs4910472, p = 2.31×10−11) and UCN119B/SPPL3 (rs11829037, p = 8.91×10−10) loci; for MCP-1, near its receptor CCR2 (rs17141006, p = 7.53×10−13) and in CADM3 (rs3026968, p = 7.63×10−13); for hsCRP, within the CRP gene (rs3093077, p = 5.73×10−21), near DARC (rs3845624, p = 1.43×10−10), UNC119B/SPPL3 (rs11829037, p = 1.50×10−14), and ICOSLG/AIRE (rs113459440, p = 1.54×10−08) loci. Confirmatory evidence was found for IL-6 in the IL-6R gene (rs4129267); for ESR at CR1 (rs12567990) and TMEM57 (rs10903129); for MCP-1 at DARC (rs12075); and for hsCRP at CRP (rs1205), HNF1A (rs225918), and APOC-I (rs4420638). Our results improve the current knowledge of genetic variants underlying inflammation and provide novel clues for the understanding of the molecular mechanisms regulating this complex process.

Author Summary

Inflammation is a protective response of our organism to harmful stimuli—such as germs, damaged cells, or irritants—and to initiate the healing process. It has also been implicated, with both protective and predisposing effects, in a number of different diseases; but many important details of this complex phenomenon are still unknown. Identifying the genes that influence levels of pro-inflammatory molecules can help to elucidate the factors and mechanisms underlying inflammation and their consequence on health. Genome-wide association scans (GWAS) have proved successful in revealing robust associations in both common diseases and quantitative traits. Here, we thus performed a multistage GWAS in a large cohort of individuals from Sardinia to examine the role of common genetic variants on the key inflammatory biomarkers Interleukin-6, erythrocyte sedimentation rate, monocyte chemotactic protein-1, and high-sensitivity C-reactive protein. Our work identified new genetic determinants associated with the quantitative levels of these inflammatory biomarkers and confirmed known ones. Overall, the data highlight an intricate regulation of this complex biological phenomenon and reveal proteins and mechanisms that can now be followed up with adequate functional studies.

The prevalence of metabolic syndrome has paralleled the sharp increase in obesity. Given its tremendous physical, emotional, and financial burden, it is of critical importance to identify who is most at risk and the potential points of intervention. Psychological traits, in addition to physiological and social risk factors, may contribute to metabolic syndrome. The objective of the present research is to test whether personality traits are associated with metabolic syndrome in a large community sample. Participants (N = 5,662) from Sardinia, Italy, completed a comprehensive personality questionnaire, the NEO-PI-R, and were assessed on all components of metabolic syndrome (waist circumference, triglycerides, high-density lipoprotein cholesterol, blood pressure, and fasting glucose). Logistic regressions were used to predict metabolic syndrome from personality traits, controlling for age, sex, education, and current smoking status. Among adults over age 45 (n = 2,419), Neuroticism and low Agreeableness were associated with metabolic syndrome, whereas high Conscientiousness was protective. Individuals who scored in the top 10% on Conscientiousness were approximately 40% less likely to have metabolic syndrome (OR = 0.61, 95% CI = 0.41–0.92), whereas those who scored in the lowest 10% on Agreeableness were 50% more likely to have it (OR = 1.53, 95% CI = 1.09–2.16). At the facet level, traits related to impulsivity and hostility were the most strongly associated with metabolic syndrome. The present research indicates that those with fewer psychological resources are more vulnerable to metabolic syndrome and suggests a psychological component to other established risk factors.

Here we report the generation and characterization of 84 mouse ES cell lines with doxycycline-controllable transcription factors (TFs) which, together with the previous 53 lines, cover 7–10% of all TFs encoded in the mouse genome. Global gene expression profiles of all 137 lines after the induction of TFs for 48 hrs can associate each TF with the direction of ES cell differentiation, regulatory pathways, and mouse phenotypes. These cell lines and microarray data provide building blocks for a variety of future biomedical research applications as a community resource.

Background

Independent of temporal circumstances, some individuals have greater susceptibility to depressive affects, such as feelings of guilt, sadness, hopelessness, and loneliness. Identifying the genetic variants that contribute to these individual differences can point to biological pathways etiologically involved in psychiatric disorders.

Methods

Genome-wide association scans (GWA or GWAS) for the Depression scale of the Revised NEO Personality Inventory (NEO-PI-R) in community-based samples from a genetically homogeneous area of Sardinia, Italy (N = 3,972) and from the Baltimore Longitudinal Study of Aging in the US (N = 839).

Results

Meta-analytic results for genotyped or imputed single nucleotide polymorphisms (SNPs) indicate that the strongest association signals for trait depression were found in RORA (rs12912233; p= 6 × 10−7), a gene involved in circadian rhythm. A plausible biological association was also found with SNPs within GRM8 (rs17864092; p = 5 × 10−6), a metabotropic receptor for glutamate, a major excitatory neurotransmitter in the central nervous system.

Conclusions

These findings suggest shared genetic basis underlying the continuum from personality traits to psychopathology.

Complex trait genome-wide association studies (GWAS) provide an efficient strategy for evaluating large numbers of common variants in large numbers of individuals and for identifying trait-associated variants. Nevertheless, GWAS often leave much of the trait heritability unexplained. We hypothesized that some of this unexplained heritability might be due to common and rare variants that reside in GWAS identified loci but lack appropriate proxies in modern genotyping arrays. To assess this hypothesis, we re-examined 7 genes (APOE, APOC1, APOC2, SORT1, LDLR, APOB, and PCSK9) in 5 loci associated with low-density lipoprotein cholesterol (LDL-C) in multiple GWAS. For each gene, we first catalogued genetic variation by re-sequencing 256 Sardinian individuals with extreme LDL-C values. Next, we genotyped variants identified by us and by the 1000 Genomes Project (totaling 3,277 SNPs) in 5,524 volunteers. We found that in one locus (PCSK9) the GWAS signal could be explained by a previously described low-frequency variant and that in three loci (PCSK9, APOE, and LDLR) there were additional variants independently associated with LDL-C, including a novel and rare LDLR variant that seems specific to Sardinians. Overall, this more detailed assessment of SNP variation in these loci increased estimates of the heritability of LDL-C accounted for by these genes from 3.1% to 6.5%. All association signals and the heritability estimates were successfully confirmed in a sample of ∼10,000 Finnish and Norwegian individuals. Our results thus suggest that focusing on variants accessible via GWAS can lead to clear underestimates of the trait heritability explained by a set of loci. Further, our results suggest that, as prelude to large-scale sequencing efforts, targeted re-sequencing efforts paired with large-scale genotyping will increase estimates of complex trait heritability explained by known loci.

Author Summary

Despite the striking success of genome-wide association studies in identifying genetic loci associated with common complex traits and diseases, much of the heritable risk for these traits and diseases remains unexplained. A higher resolution investigation of the genome through sequencing studies is expected to clarify the sources of this missing heritability. As a preview of what we might learn in these more detailed assessments of genetic variation, we used sequencing to identify potentially interesting variants in seven genes associated with low-density lipoprotein cholesterol (LDL-C) in 256 Sardinian individuals with extreme LDL-C levels, followed by large scale genotyping in 5,524 individuals, to examine newly discovered and previously described variants. We found that a combination of common and rare variants in these loci contributes to variation in LDL-C levels, and also that the initial estimate of the heritability explained by these loci doubled. Importantly, our results include a Sardinian-specific rare variant, highlighting the need for sequencing studies in isolated populations. Our results provide insights about what extensive whole-genome sequencing efforts are likely to reveal for the understanding of the genetic architecture of complex traits.

Unhealthy lipid levels are among the leading controllable risk factors for coronary heart disease. To identify the psychological factors associated with dyslipidemia, this study investigates the personality correlates of cholesterol (total, LDL, and HDL) and triglycerides. A community-based sample (N=5,532) from Sardinia, Italy, had their cholesterol and triglyceride levels assessed and completed a comprehensive personality questionnaire, the NEO-PI-R. All analyses controlled for age, sex, BMI, smoking, drinking, hypertension, and diabetes. Low Conscientiousness and traits related to impulsivity were associated with lower HDL cholesterol and higher triglycerides. Compared to the lowest 10%, those who scored in top 10% on Impulsivity had a 2.5 times greater risk of exceeding the clinical threshold for elevated triglycerides (OR=2.51, CI=1.56–4.07). In addition, sex moderated the association between trait depression (a component of Neuroticism) and HDL cholesterol, such that trait depression was associated with lower levels of HDL cholesterol in women but not men. When considering the connection between personality and health, unhealthy lipid profiles may be one intermediate biomarker between personality and morbidity and mortality.

Brain-derived neurotrophic factor (BDNF) regulates synaptic plasticity and neurotransmission, and has been linked to neuroticism, a major risk factor for psychiatric disorders. A recent genome-wide association (GWA) scan, however, found the BDNF Val66Met polymorphism (rs6265) associated with extraversion but not with neuroticism. In this study, we examine the links between BDNF and personality traits, assessed using the Revised NEO Personality Inventory (NEO-PI-R), in a sample from SardiNIA (n=1560) and the Baltimore Longitudinal Study of Aging (BLSA; n=1131). Consistent with GWA results, we found that BDNF Met carriers were more introverted. By contrast, in both samples and in a meta-analysis inclusive of published data (n=15251), we found no evidence for a main effect of BDNF Val66Met on neuroticism. Finally, on the basis of recent reports of an epistatic effect between BDNF and the serotonin transporter, we explored a Val66Met × 5-HTTLPR interaction in a larger SardiNIA sample (n=2333). We found that 5-HTTLPR LL carriers scored lower on neuroticism in the presence of the BDNF Val variant, but scored higher on neuroticism in the presence of the BDNF Met variant. Our findings support the association between the BDNF Met variant and introversion and suggest that BDNF interacts with the serotonin transporter gene to influence neuroticism.

The goals of this cross-sectional study were to explore correlates of walking speed in a large wide age-ranged population and to identify factors affecting lower walking speed at older ages. Participants were 3,872 community-dwelling adults in the first follow-up of the SardiNIA study who completed a 4-m walking test. Sex-specific correlates of walking speed included marital status, height, waist circumference, pulse wave velocity, comorbidity, subjective health, strength, and personality. Effect modifiers of the age–walking speed association included extraversion (<55 years, p = .019) and education (<55 years, p = .021; ≥55 years, p = .012) in women, and openness (<55 years, p = .005), waist circumference (<55 years, p = .010), and subjective health (<55 years, p = .014) in men. The strong impact of personality suggests that certain personality traits may be associated with behaviors that affect physical performance and condition the reduced mobility mostly at younger ages. If these patterns are confirmed in longitudinal studies, personality may be an important target for prevention.

Aims

We evaluated whether specific clusters of metabolic syndrome (MetS) components differentially impact on arterial structure and function, and whether the impact is similar in men and in women.

Methods and results

Components of the MetS and arterial properties were assessed in 6148 subjects, aged 14–102 in a cluster of four towns in Sardinia, Italy. MetS was defined in accordance with the ATP III criteria. Age groups were classified as: <35, 35–49, 50–64, and ≥65 years. Systolic blood pressure (BP), diastolic BP, pulse pressure, common carotid artery (CCA) diameter, intima–media thickness, distensibility, strain, stiffness index, wall stress, and aortic pulse wave velocity were measured. Common carotid artery plaque was defined as focal encroachment of the arterial wall and CCA calcification as acoustic shadowing. In any age group, subjects with MetS presented thicker, stiffer or less distensible, and wider large arteries than controls. The arterial burden of MetS increased as the number of altered MetS components increased. However, not all MetS components were associated with the same changes in arterial properties. In fact, specific clusters of MetS components, i.e. any combination of altered glucose tolerance, elevated BP, and elevated triglycerides (with or without abdominal obesity), dramatically increased age-associated arterial changes. The impact of MetS on arterial function was similar in men and women.

Conclusion

MetS accelerates age-associated arterial changes, even in older persons. However, not all the clusters of MetS components render the same burden on arterial structure and function.

Background

High Neuroticism and low Conscientiousness are frequently implicated in health-risk behaviors, such as smoking and overeating, as well as health outcomes, including mortality. Their associations with physiological markers of morbidity and mortality, such as inflammation, are less well documented. The present research examines the association between the five major dimensions of personality and interleukin-6 (IL-6), a pro-inflammatory cytokine often elevated in patients with chronic morbidity and frailty.

Methods

A population-based sample (N=4,923) from four towns in Sardinia, Italy, had their levels of IL-6 measured and completed a comprehensive personality questionnaire, the NEO-PI-R. Analyses controlled for factors known to have an effect on IL-6: age, sex, smoking, weight, aspirin use, and disease burden.

Results

High Neuroticism and low Conscientiousness were both associated with higher levels of IL-6. The findings remained significant after controlling for the relevant covariates. Similar results were found for C-reactive protein, a related marker of chronic inflammation. Further, smoking and weight partially mediated the association between impulsivity-related traits and higher IL-6 levels. Finally, logistic regressions revealed that participants either in the top 10% of the distribution of Neuroticism or the bottom 10% of Conscientiousness had an approximately 40% greater risk of exceeding clinically-relevant thresholds of IL-6.

Conclusions

Consistent with the literature on personality and self-reported health, individuals high on Neuroticism or low on Conscientiousness show elevated levels of this inflammatory cytokine. Identifying critical medical biomarkers associated with personality may help to elucidate the physiological mechanisms responsible for the observed connections between personality traits and physical health.

The discovery that the SRY gene induces male sex in humans and other mammals led to speculation about a possible equivalent for female sex. But females are proving to be more complicated. Several master genes appear to be autonomously involved, and female sex determination seems to remain relatively labile. Partial loss of function of the transcription factor FOXL2 leads to premature ovarian failure in women; and in animal models, Foxl2 is required for folliculogenesis as well as for maintenance, and possibly induction, of female sex determination. In the germ line, oocytes form apparently normally even in the absence of Foxl2, dependent on genes that include female-specific factors such as Fig-alpha, Nobox, etc. In the soma, ablation of Foxl2 or the independently expressed gene Wnt4 (likely downstream of Rspo1) can produce partial testis differentiation in XX mice, and the double knockout results in the formation of tubules and spermatogonia. This indicates that at least two autonomous ovarian pathways are required to antagonize testis differentiation in females, a finding that is being increasingly corroborated by studies in goats and non-mammalian vertebrates. In recent expression profiling of mouse ovaries that lack Foxl2 alone or in combination with Wnt4 or Kit/c-Kit, we found that following Foxl2 loss, early testis genes (including the downstream effector of Sry, Sox9) and several novel ovarian genes were consistently dysregulated during embryo-fetal development. The results support the proposal of dose-dependent Foxl2 function and anti-testis action. A partial working model for somatic development and sex determination is presented in which Sox9 is direct antagonist of Foxl2 in the supporting cell lineage.

The QT interval, a measure of cardiac repolarization, predisposes to ventricular arrhythmias and sudden cardiac death (SCD) when prolonged or shortened. A common variant in NOS1AP is known to influence repolarization. We analyze genome-wide data from five population-based cohorts (ARIC, KORA, SardiNIA, GenNOVA and HNR) with a total of 15,842 individuals of European ancestry, to confirm the NOS1AP association and identify nine additional loci at P < 5 × 10−8. Four loci map near the monogenic long-QT syndrome genes KCNQ1, KCNH2, SCN5A and KCNJ2. Two other loci include ATP1B1 and PLN, genes with established electrophysiological function, whereas three map to RNF207, near LITAF and within NDRG4-GINS3-SETD6-CNOT1, respectively, all of which have not previously been implicated in cardiac electrophysiology. These results, together with an accompanying paper from the QTGEN consortium, identify new candidate genes for ventricular arrhythmias and SCD.

A large body of evidence links antagonism-related traits with cardiovascular outcomes, but less is known about how psychological traits are associated with intermediate markers of cardiovascular disease. Using a large, community-based sample from Sardinia, Italy (N=5,614), this study examined how trait antagonism (low Agreeableness) and its facets are associated with carotid artery intima-media thickness (IMT), a measure of arterial thickening. Controlling for demographic and cardiovascular risk factors, low Agreeableness, and in particular low Straightforwardness and low Compliance, were associated with greater carotid thickening, measured concurrently and prospectively, and with increases in IMT over three years. Indeed, those in the bottom 10% of Agreeableness had a 40% increase in risk for elevated IMT. Although men have thicker arterial walls, women with antagonistic traits had similar carotid thickening as antagonistic men. Antagonistic individuals, especially those who are manipulative and aggressive, have greater increases in arterial thickening, independent of traditional cardiovascular risk factors.

SUMMARY

To examine transcription factor (TF) network(s), we created mouse ES cell lines, in each of which one of 50 TFs tagged with a FLAG moiety is inserted into a ubiquitously controllable tetracycline-repressible locus. Of the 50 TFs, Cdx2 provoked the most extensive transcriptome perturbation in ES cells, followed by Esx1, Sox9, Tcf3, Klf4, and Gata3. ChIP-Seq revealed that CDX2 binds to promoters of up-regulated target genes. By contrast, genes down-regulated by CDX2 did not show CDX2 binding, but were enriched with binding sites for POU5F1, SOX2, and NANOG. Genes with binding sites for these core TFs were also down-regulated by the induction of at least 15 other TFs, suggesting a common initial step for ES cell differentiation mediated by interference with the binding of core TFs to their target genes. These ES cell lines provide a fundamental resource to study biological networks in ES cells and mice.

Identifying genetic variants that influence human height will further our understanding of skeletal growth and development. A number of rare genetic variants have been convincingly and reproducibly associated with height in Mendelian syndromes, and common variants in HMGA2 were recently found to be associated with variation in height in the general population1. Here, we report genome-wide association analyses of 6,669 individuals from Finland and Sardinia, using genotyped and imputed markers, and follow-up in an additional 28,801 individuals. We show that common variants in the osteoarthritis-associated2 GDF5-BFZB locus are responsible for variation in height (estimated additive effect of 0.44 cm, overall p<10−15). Our results suggest a link between the genetic basis of height and osteoarthritis, potentially mediated through alterations in bone growth and development.

Bilirubin, resulting largely from the turnover of hemoglobin, is found in the plasma in two main forms: unconjugated or conjugated with glucuronic acid. Unconjugated bilirubin is transported into hepatocytes. There, it is glucuronidated by UGT1A1 and secreted into the bile canaliculi. We report a genome wide association scan in 4300 Sardinian individuals for total serum bilirubin levels. In addition to the two known loci previously involved in the regulation of bilirubin levels, UGT1A1 (P = 6.2 × 10−62) and G6PD (P = 2.5 × 10−8), we observed a strong association on chromosome 12 within the SLCO1B3 gene (P = 3.9 × 10−9). Our findings were replicated in an independent sample of 1860 Sardinians and in 832 subjects from the Old Order Amish (combined P < 5 × 10−14). We also show that SLC01B3 variants contribute to idiopathic mild unconjugated hyperbilirubinemia. Thus, SLC01B3 appears to be involved in the regulation of serum bilirubin levels in healthy individuals and in some bilirubin-related disorders that are only partially explained by other known gene variants.

Personality traits are summarized by five broad dimensions with pervasive influences on major life outcomes, strong links to psychiatric disorders, and clear heritable components. To identify genetic variants associated with each of the five dimensions of personality we performed a genome wide association (GWA) scan of 3,972 individuals from a genetically isolated population within Sardinia, Italy. Based on analyses of 362,129 single nucleotide polymorphisms (SNPs) we found several strong signals within or near genes previously implicated in psychiatric disorders. They include the association of Neuroticism with SNAP25 (rs362584, P = 5 × 10−5), Extraversion with BDNF and two cadherin genes (CDH13 and CDH23; Ps < 5 × 10−5), Openness with CNTNAP2 (rs10251794, P = 3 × 10−5), Agreeableness with CLOCK (rs6832769, P = 9 × 10−6), and Conscientiousness with DYRK1A (rs2835731, P = 3 × 10−5). Effect sizes were small (less than 1% of variance), and most failed to replicate in the follow-up independent samples (N up to 3,903), though the association between Agreeableness and CLOCK was supported in two of three replication samples (overall P = 2 × 10−5). We infer that a large number of loci may influence personality traits and disorders, requiring larger sample sizes for the GWA approach to identify significant genetic variants.