Page 56 - Hormel Institute Annual Report 2021-22

Chuanhe Yu, PhD
“Chromatin, which contains both genetic and epigenetic information, must be stably transmitted to daughter cells during mitotic cell divisions to maintain genome integrity
and cell identity.”
Chuanhe Yu
56 | THE HORMEL INSTITUTE // Inheritance of
Epigenetic Information
ASSISTANT PROFESSOR
UNIVERSITY OF MINNESOTA
Parental histone recycling is a crucial
stage in epigenetic inheritance. The DNA polymerase epsilon subunit and DPB3 DNA
replication helicase subunit MCM2 (Minichromo- some maintenance) are both involved in parental histone transfer to the leading and lagging strands, respectively, according to our findings. The impact and significance of these parental histone transfer pathways on chromatin structure and DNA repair is elusive. We find that double mutant (Dpb3 deletion and MCM2 mutant) neutralizes the single mutant’s asymmetric
parental histone pattern, demonstrating that
the leading and lagging strand parental histone transfers processes are independent. The MCM2 mutant, DPB3 deletion mutants, and the double mutant have a much lower homologous recom- bination frequency, which is likely related to the levitated free histone level. Our study indicates that the proper transfer of parental histone to DNA replication leading and lagging strands is required for maintaining chromatin structure. The higher cellular free histone level due to parental histone transfer defect is detrimental to cells.