Bidirectional transcription initiation marks accessible chromatin and is not specific to enhancers

Abstract Background Enhancers are modular regulatory elements that are central to the spatial and temporal regulation of gene expression. Bidirectional transcription initiating at enhancers has been proposed to mark active enhancers and as such has been utilized to experimentally identify active enhancers de novo. Results Here, we show that bidirectional transcription initiation is a pervasive feature of accessible chromatin, including at enhancers, promoters, and other DNase hypersensitive regions not marked with canonical histone modification profiles. Transcription is less predictive for enhancer activity than epigenetic modifications such as H3K4me1 or the accessibility of DNA when measured both in enhancer assays and at endogenous loci. The stability of enhancer initiated transcripts does not influence measures of enhancer activity and we cannot detect evidence of purifying selection on the resulting enhancer RNAs within the human population. Conclusions Our results indicate that bidirectional transcription initiation from accessible chromatin is not sufficient for, nor specific to, enhancer activity. Transcription initiating at enhancers may be a frequent by-product of promiscuous RNA polymerase initiation at accessible chromatin and is unlikely to generally play a functional role in enhancer activity

Alcohol impairs speed of information processing and simple and choice reaction time and differentially impairs higher-order cognitive abilities

Previous research has demonstrated that alcohol impairs information processing. However, it is unknown whether this impairment is on all stages of information processing, or on the early, rather than on the later, stages of information processing. Thus, the aim of the present study was to examine the effects of orally administered alcohol on both the early and the later stages of information processing. The present study assessed inspection time (IT), simple reaction time, choice reaction time and cognitive ability (Wechsler Adult Intelligence Scale - Revised) in 16 adult participants in both alcohol and placebo conditions. IT (a measure of the early stages of information processing) was used as a predictor variable in a linear regression to examine whether a disruption of the early stages of information processing accounted for changes in total information processing after alcohol administration. Results indicated that alcohol significantly slowed total information processing, independently of the early stages of information processing