LAUSR

The chromatin structure in one‐cell‐stage mouse embryos is extremely loose and becomes tighter at the two‐cell stage. As linker histones are involved in higher‐order chromatin structure, we examined the involvement of the linker histone variant H1foo in the change of chromatin looseness between the one‐ and two‐cell stages. H1foo knockdown causes the chromatin structure to be tighter in the pronucleus and increases deposition of the histone H3 variant H3.1/3.2 in the peripheral region of the pronucleus in one‐cell‐stage embryos. The decrease in chromatin looseness at the two‐cell stage is less after overexpressing H1foo. These results suggest that H1foo is involved in the change in chromatin structure via nuclear deposition of H3 variants between the one‐ and two‐cell stages.