Regulatory Functions and Chromatin Loading Dynamics of Linker Histone H1 During Endoreplication in Drosophila

ABSTRACT: Purpose: In Drosophila larval tissues that undergo endoreplication without cell division, the latest-replicating regions occasionally fail to complete endoreplication, resulting in the establishment of underreplicated (UR) domains of polytene chromosomes. The cause of this phenomenon is poorly understood. Methods: Freshly dissected salivary glands were crosslinked, nuclei were sonicated to shear DNA at an average size of 200 bp, and DNA was purified using a QiaQuick PCR Purification Kit. Sequencing libraries were prepared using the Illumina HiSeq 2500 system. UR regions were identified in aligned reads of the control knockdown by scanning along 5-kb windows, with regions designated as under-replicated if 20 consecutive windows fell below the average per-chromosome read count. Fold change was then calculated between the H1-depleted and control-depleted samples. Results: We found that H1 is required for the underreplication phenomenon in Drosophila salivary glands, as UR regions show substantial increase in copy number upon H1 depletion. Conclusions: Our findings implicate H1 as a critical factor in the formation of UR regions and as an important upstream effector of SUUR.

ORGANISM(S): Drosophila melanogaster

PROVIDER: GSE95215 | GEO | 2017/08/22

SECONDARY ACCESSION(S): PRJNA376423

REPOSITORIES: GEO