TY  - JOUR
A1  - Drews, Franziska
A1  - Salhab, Abdulrahman
A1  - Karunanithi, Sivarajan
A1  - Cheaib, Miriam
A1  - Jung, Martin
A1  - Schulz, Marcel Holger
A1  - Simon, Martin
T1  - Broad domains of histone marks in the highly compact Paramecium macronuclear genome
T2  - Genome research
N2  - The unicellular ciliate Paramecium contains a large vegetative macronucleus with several unusual characteristics, including an extremely high coding density and high polyploidy. As macronculear chromatin is devoid of heterochromatin, our study characterizes the functional epigenomic organization necessary for gene regulation and proper Pol II activity. Histone marks (H3K4me3, H3K9ac, H3K27me3) reveal no narrow peaks but broad domains along gene bodies, whereas intergenic regions are devoid of nucleosomes. Our data implicate H3K4me3 levels inside ORFs to be the main factor associated with gene expression, and H3K27me3 appears in association with H3K4me3 in plastic genes. Silent and lowly expressed genes show low nucleosome occupancy, suggesting that gene inactivation does not involve increased nucleosome occupancy and chromatin condensation. Because of a high occupancy of Pol II along highly expressed ORFs, transcriptional elongation appears to be quite different from that of other species. This is supported by missing heptameric repeats in the C-terminal domain of Pol II and a divergent elongation system. Our data imply that unoccupied DNA is the default state, whereas gene activation requires nucleosome recruitment together with broad domains of H3K4me3. In summary, gene activation and silencing in Paramecium run counter to the current understanding of chromatin biology.
Y1  - 2022
UR  - http://publikationen.ub.uni-frankfurt.de/frontdoor/index/index/docId/73774
UR  - https://nbn-resolving.org/urn:nbn:de:hebis:30:3-737743
SN  - 1549-5469
SN  - 1088-9051
VL  - 32
SP  - 710
EP  - 725
PB  - Laboratory Press
CY  - Cold Spring Harbor, NY
ER  -