DNA double-strand break (DSB) repair is essential for maintenance of genome stability. Recent work has implicated a host of chromatin regulators in the DNA damage response, and although several functional roles have been defined, the mechanisms that control their recruitment to DNA lesions remain unclear. Here, we find that efficient DSB recruitment of the INO80, SWR-C, NuA4, SWI/SNF, and RSC enzymes is inhibited by the non-homologous end joining machinery, and that their recruitment is controlled by early steps of homologous recombination. Strikingly, we find no significant role for H2A.X phosphorylation (γH2AX) in the recruitment of chromatin regulators, but rather their recruitment coincides with reduced levels of γH2AX. Our work indicates that cell cycle position plays a key role in DNA repair pathway choice and that recruitment of chromatin regulators is tightly coupled to homologous recombination.

The DNA damage response to double-strand breaks (DSBs) is critical for cellular viability. Recent work has shown that a host of chromatin regulators are recruited to a DSB, and that they are important for the DNA damage response. However, the functional relationships between different chromatin regulators at DSBs remain unclear. Here we describe a conserved functional interaction among the chromatin remodeling enzyme, SWI/SNF, the NuA4 and Gcn5 histone acetyltransferases, and phosphorylation of histone H2A.X (γH2AX). Specifically, we find that the NuA4 and Gcn5 enzymes are both required for the robust recruitment of SWI/SNF to a DSB, which in turn promotes the phosphorylation of H2A.X.

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We examined the ability of 150-166 undergraduate students to assign four negative emotions (sadness, fear, disgust, and anger) to five sets of emotion expression stimuli: a standard of face photographs expressing basic emotions, faces that were morphs of standards for these emotions, a special set of faces that was designed to detect different components of disgust expressions, and two sets of dynamic, video clips displays of emotions as described in traditional Hindu scriptures and used in classical Hindu dance. One of these sets presented the full body traditional displays (including hands and face), while in the second set, the same clips were used but the facial expressions were blocked out. Participants also completed an obsessive compulsive inventory and the disgust scale. Major findings are that: (a) there are some substantial individual differences in ability to correctly identify emotions; (b) the ability to detect facial emotions correlates substantially (.49) with ability to detect bodily emotions; (c) there is no evidence for specific deficits in the detection of any particular emotion; and (d) there is no relation between individual differences in obsessive-compulsive disorder (OCD) tendencies or disgust sensitivity, in a normal sample and the ability to detect disgust.

We suggest future research and clinical directions that will ultimately assist clinicians to provide high-quality mental health services to African American children.