A major yet unresolved quest in decoding the human genome is the identification of the regulatory sequences that control the spatial and temporal expression of genes. Distant-acting transcriptional enhancers are particularly challenging to uncover because they are scattered among the vast noncoding portion of the genome. Evolutionary sequence constraint can facilitate the discovery of enhancers, but fails to predict when and where they are active in vivo. Here we present the results of chromatin immunoprecipitation with the enhancer-associated protein p300 followed by massively parallel sequencing, and map several thousand in vivo binding sites of p300 in mouse embryonic forebrain, midbrain and limb tissue. We tested 86 of these sequences in a transgenic mouse assay, which in nearly all cases demonstrated reproducible enhancer activity in the tissues that were predicted by p300 binding. Our results indicate that in vivo mapping of p300 binding is a highly accurate means for identifying enhancers and their associated activities, and suggest that such data sets will be useful to study the role of tissue-specific enhancers in human biology and disease on a genome-wide scale.The initial sequencing of the human genome 1,2 , complemented by effective computational and experimental strategies for mammalian gene discovery 3,4 , has resulted in a virtually complete list of protein-coding sequences. In contrast, the genomic location and function of regulatory elements that orchestrate gene expression in the developing and adult body remain more obscure, hindering studies of their contribution to developmental processes and human disease. Evolutionary constraint of non-coding sequences can predict the location of enhancers in the genome 5-12 , but does not reveal when and where these enhancers are active in vivo. Furthermore, it has been suggested that a substantial proportion of regulatory elements is not sufficiently conserved to be detectable by comparative genomic methods [13][14][15][16] .

Context Although young adulthood is often characterized by rapid intellectual and social development, college-age individuals are also commonly exposed to circumstances that place them at risk for psychiatric disorders. Objective To assess 12-month prevalence of psychiatric disorders, sociodemographic correlates, and rates of treatment among individuals attending college and their non-college attending peers in the United States. Design, Setting, Participants Face-to-face interviews were conducted in the 2001-2002 National Epidemiologic Survey on Alcohol and Related Conditions ([NESARC] n=43,093). Analyses were done for the subsample of college-age individuals, defined as those aged 19-25 that were both attending (n=2,188) and not attending college (n=2,904) in the previous year. Main Outcome Measure Sociodemographic correlates and prevalence of 12-month DSM-IV psychiatric disorders, substance use, and treatment seeking among college-attending individuals and their non-college attending peers. Results Almost half of college-age individuals had a psychiatric disorder in the past year. The overall rate of psychiatric disorders was not different between college-attending individuals and their non-college attending peers. The unadjusted risk of alcohol use disorders was significantly greater for college students than their non-college attending peers (OR: 1.25, 95%, CI:1.04-1.50), though not after adjusting for background socio-demographic characteristics (AOR: 1.19, 95%: 0.98-1.44). College students were significantly less likely (unadjusted and adjusted) to have a diagnosis of drug use disorder or nicotine dependence or have used tobacco than their non-college-attending peers. Bipolar disorder was less common in individuals attending college. College students were significantly less likely to receive past year treatment for alcohol/drug use disorders than their non-college-attending peers. Conclusions Psychiatric disorders, particularly alcohol use disorders, are common in the college-age population. Although treatment rates varied across disorders, overall, less than 25% of individuals with a mental disorder sought treatment in the year prior to the survey. These findings underscore the importance of treatment and prevention interventions among college-age individuals.

Accurate control of tissue-specific gene expression plays a pivotal role in heart development, but few cardiac transcriptional enhancers have thus far been identified. Extreme non-coding sequence conservation successfully predicts enhancers active in many tissues, but fails to identify substantial numbers of heart enhancers. Here we used ChIP-seq with the enhancer-associated protein p300 from mouse embryonic day 11.5 heart tissue to identify over three thousand candidate heart enhancers genome-wide. Compared to other tissues studied at this time-point, most candidate heart enhancers are less deeply conserved in vertebrate evolution. Nevertheless, the testing of 130 candidate regions in a transgenic mouse assay revealed that most of them reproducibly function as enhancers active in the heart, irrespective of their degree of evolutionary constraint. These results provide evidence for a large population of poorly conserved heart enhancers and suggest that the evolutionary constraint of embryonic enhancers can vary depending on tissue type.

Development and function of the human heart depend on the dynamic control of tissue-specific gene expression by distant-acting transcriptional enhancers. To generate an accurate genome-wide map of human heart enhancers, we used an epigenomic enhancer discovery approach and identified ∼6,200 candidate enhancer sequences directly from fetal and adult human heart tissue. Consistent with their predicted function, these elements were markedly enriched near genes implicated in heart development, function and disease. To further validate their in vivo enhancer activity, we tested 65 of these human sequences in a transgenic mouse enhancer assay and observed that 43 (66%) drove reproducible reporter gene expression in the heart. These results support the discovery of a genome-wide set of non-coding sequences highly enriched in human heart enhancers which is likely to facilitate down-stream studies of the role of enhancers in development and pathological conditions of the heart.