Dissecting relative contributions of cis- and trans-determinants to nucleosome distribution by comparing Tetrahymena macronuclear and micronuclear chromatin.
Nucleic Acids Res
; 44(21): 10091-10105, 2016 12 01.
Article
en En
| MEDLINE
| ID: mdl-27488188
ABSTRACT
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 and flanking splice sites. Transcription-associated trans-determinants promote nucleosome positioning in MAC. By contrast, nucleosomes in MIC are dramatically delocalized. Nucleosome occupancy in MAC and MIC are nonetheless highly correlated with each other, as well as with in vitro reconstitution and predictions based upon DNA sequence features, revealing unexpectedly strong contributions from cis-determinants. In particular, well-positioned nucleosomes are often matched with GC content oscillations. As many nucleosomes are coordinately accommodated by both cis- and trans-determinants, we propose that their distribution is shaped by the impact of these nucleosomes on the mutational and transcriptional landscape, and driven by evolutionary selection.
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Cromatina
/
Nucleosomas
/
Tetrahymena thermophila
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Macronúcleo
Idioma:
En
Revista:
Nucleic Acids Res
Año:
2016
Tipo del documento:
Article
País de afiliación:
Estados Unidos