Forming an Ectopic Histone Locus Body in Human Cells with a Mouse Histone Gene Cluster (2015)
Undergraduate: Clark Cunningham
Faculty Advisor: William Marzluff
Department: Biology
Because of their role in DNA packaging, most histone genes are replication dependent; expression of these histone genes occurs exclusively during the S-phase of the cell cycle when DNA is replicated and their mRNAs are rapidly degraded at the end of S-phase. The rapid synthesis of histone mRNA occurs at clusters of histone genes which are regulated by protein complexes called Histone Locus Bodies (HLBs). While the process of HLB formation is presently unknown, experiments in D. melanogaster have shown that the intergenic region between a pair of H3-H4 genes is necessary and sufficient for HLB formation. In M. musculus, a long, non-coding RNA (lncRNA) has been identified by deep sequencing in between a highly conserved pair of duplicated histone H2a and H3 genes at the mouse histone 2 locus. My experiments are designed to examine the role of this lncRNA on HLB formation and histone gene expression at mouse histone locus 2. I have created several transgenic lines of HeLa cells by transfecting human cell lines with a copy of the entire mouse histone locus 2 on a 187 kb BAC. These cells express the mouse histone genes present in histone locus 2. In future experiments, I plan to knockdown the lncRNA and/or mutate the lncRNA promoter region on the BAC and observe the effect on mouse histone gene expression and HLB formation in human cell lines.