ß-actin contributes to open chromatin for activation of the adipogenic pioneer factor CEBPA during transcriptional reprograming.

Adipogenesis is regulated by a cascade of signals that drive transcriptional reprogramming in adipocytes. Here, we report that nuclear actin regulates the chromatin states that establish tissue- specific expression during adipogenesis. To study the role of ß-actin in adipocyte differentiation, we conducted RNA sequencing on wild-type and ß-actin knockout mouse embryonic fibroblasts (MEFs) after reprograming to adipocytes. We found that ß-actin depletion affects induction of several adipogenic genes during transcriptional reprograming. This impaired regulation of adipogenic genes is linked to reduced expression of the pioneer factor Cebpa and is rescued by reintroducing NLS-tagged ß-actin. ATAC-Seq in knockout MEFs revealed that actin-dependent reduction of Cebpa expression correlates with decreased chromatin accessibility and loss of chromatin association of the ATPase Brg1. This, in turn, impairs CEBPB's association with its Cebpa promoter-proximal binding site during adipogenesis. We propose a role for the nuclear ß-actin pool in maintaining open chromatin for transcriptional reprogramming during adipogenic differentiation.

More normal than not: a qualitative assessment of the developmental experiences of gay male youth.

PURPOSE: To examine gay youth experiences within the context of normal adolescent development. METHODS: Thematic analyses of interviews with 13 self-identified gay male youth, aged 16-22 years, each reporting minimal sexual identity distress, were completed. Interviews focused on: (a) descriptions of developmental changes perceived to occur for all adolescents, (b) descriptions of the participants' developmental experience, and (c) participants' direct comparisons of their perceptions of gay and nongay developmental experience. Data were analyzed by two investigators who, after initial review of the interview transcripts, developed a unified coding template to permit systematic analysis of the transcripts for recurrent themes. RESULTS: (a) Few (2 of 13) participants reported overall developmental experience markedly different from nongay peers. (b) Peer interaction was seen as the domain most different from that of nongay peers. (c) Open gay self-identification altered, generally positively, all peer interaction. (d) Increased peer interaction enhanced maturity in other domains. (e) Family dynamics were not substantively altered by open gay self-identification. (f) Middle and high school were identified as relatively hostile environments in which to openly identify as gay, affecting the timing and the extent of self-disclosure. (g) Developmental progress showed asynchrony across developmental domains. CONCLUSION: General developmental dysfunction is not inevitable for gay adolescents, nor is identifiable personal or family pathology directly related to sexual identity.