The 3 ' processing of antisense RNAs physically links to chromatin-based transcriptional control
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
Authors: Fang, Xiaofeng; Wu, Zhe; Raitskin, Oleg; Webb, Kimberly; Voigt, Philipp; Lu, Tiancong; Howard, Martin; Dean, Caroline
Abstract
Noncoding RNA plays essential roles in transcriptional control and chromatin silencing. At Arabidopsis thaliana FLC, antisense transcription quantitatively influences transcriptional output, but the mechanism by which this occurs is still unclear. Proximal polyadenylation of the antisense transcripts by FCA, an RNA-binding protein that physically interacts with RNA 3' processing factors, reduces FLC transcription. This process genetically requires FLD, a homolog of the H3K4 demethylase LSD1. However, the mechanism linking RNA processing to FLD function had not been established. Here, we show that FLD tightly associates with LUMINIDEPENDENS (LD) and SET DOMAIN GROUP 26 (SDG26) in vivo, and, together, they prevent accumulation of monomethylated H3K4 (H3K4me1) over the FLC gene body. SDG26 interacts with the RNA 3' processing factor FY (WDR33), thus linking activities for proximal polyadenylation of the antisense transcripts to FLD/LD/SDG26-associated H3K4 demethylation. We propose this demethylation antagonizes an active transcription module, thus reducing H3K36me3 accumulation and increasing H3K27me3. Consistent with this view, we show that Polycomb Repressive Complex 2 (PRC2) silencing is genetically required by FCA to repress FLC. Overall, our work provides insights into RNA-mediated chromatin silencing.
Cold exposure induces the acquisition of brown adipocyte gene expression profiles in cattle inguinal fat normalized with a new set of reference genes for qRT-PCR
RESEARCH IN VETERINARY SCIENCE
Authors: Cao, K. X.; Hao, D.; Wang, J.; Peng, W. W.; Yan, Y. J.; Cao, H. X.; Sun, F.; Chen, H.
Abstract
The last few years have seen great advances in our understanding of browning in white adipose tissue (WAT) where white adipocytes take on characteristics of brown adipocytes. At present, the economic significance of browning for animal husbandry is beginning to be realized with the emerging evidence that browning affects body weight not only in human and rodent but in farm animals. Quantitative RT-PCR provides a quick and sensitive way to preliminary determine browning of WAT. However, there have been no established condition specific reference genes for browning of cattle WAT. As the results showed, the most two stable reference genes for diet treatment were Wdr33 (M = 0.38) and Hdac3 (M = 0.43), while the most three internal controls for temperature treatment were Hdac3 (M = 0.28), Wdr33 (M = 0.32), and Hprt1 (M = 039) among the ten candidates. The mRNA relative expression levels of selective marker genes were normalized by normalization factor (geometric mean of control genes quantities). Cold exposure rather than high energy diet induced transcript elevations of brite specific markers (Cited], Tbx1), thermoregulatory markers (brown and beige versus white markers, i.e., Cidea, Cox7a1, Ucp1), mitochondrial biogenesis markers (Nrf1, Nrf2, Tfam), and transcription regulators (brown and beige versus white markers, i.e., Pgc1 alpha (P < 0.05) in cattle inguinal fat (iWAT). Quantitative RTPCR is a preliminary study for WAT browning. In conclusion, cattle inguinal fat acquired brown adipocyte gene expression features upon cold acclimation with prerequisite identification of stable reference genes. (C) 2017 Elsevier Ltd. All rights reserved.