Superresolution light microscopy of the Drosophila histone locus body reveals a core-shell organization associated with expression of replication-dependent histone genes.

ABSTRACT: The histone locus body (HLB) is an evolutionarily conserved nuclear body that regulates the transcription and processing of replication-dependent (RD) histone mRNAs, which are the only eukaryotic mRNAs lacking a poly-A tail. Many nuclear bodies contain distinct domains, but how internal organization is related to nuclear body function is not fully understood. Here, we demonstrate using structured illumination microscopy that Drosophila HLBs have a "core-shell" organization in which the internal core contains transcriptionally active RD histone genes. The N-terminus of Mxc, which contains a domain required for Mxc oligomerization, HLB assembly, and RD histone gene expression, is enriched in the HLB core. In contrast, the C-terminus of Mxc is enriched in the HLB outer shell as is FLAS

SUBMITTER: Kemp JP 

PROVIDER: S-EPMC8108526 | biostudies-literature | 2021 Apr

REPOSITORIES: biostudies-literature