RT Journal Article
SR Electronic
T1 Distinct nucleosome distribution patterns in two structurally and functionally differentiated nuclei of a unicellular eukaryote
JF bioRxiv
FD Cold Spring Harbor Laboratory
SP 018754
DO 10.1101/018754
A1 Jie Xiong
A1 Shan Gao
A1 Wen Dui
A1 Wentao Yang
A1 Xiao Chen
A1 Sean D. Taverna
A1 Ronald E. Pearlman
A1 Wendy Ashlock
A1 Wei Miao
A1 Yifan Liu
YR 2015
UL http://biorxiv.org/content/early/2015/04/30/018754.abstract
AB The ciliate protozoan Tetrahymena thermophila contains two types of structurally and functionally differentiated nuclei: the transcriptionally active somatic macronucleus (MAC) and the transcriptionally silent germ-line micronucleus (MIC). Here we demonstrate that MAC features well-positioned nucleosomes downstream of transcription start sites (TSS) likely connected with promoter proximal pausing of RNA polymerase II, as well as in exonic regions flanking both the 5’ and 3’ splice sites. In contrast, nucleosomes in MIC are more delocalized. Nucleosome occupancy in MAC and MIC are nonetheless highly correlated with each other and with predictions based upon DNA sequence features. Arrays of well-positioned nucleosomes are often correlated with GC content oscillations, suggesting significant contributions from cis-determinants. We propose that cis- and trans-determinants may coordinately accommodate some well-positioned nucleosomes with important functions, driven by a process in which positioned nucleosomes shape the mutational landscape of associated DNA sequences, while the DNA sequences in turn reinforce nucleosome positioning.