Histone H1oo (H1FOO)

May play an integral role in the control of gene expression during oogenesis and early embryogenesis, presumably through the perturbation of chromatin structure. Essential for meiotic maturation of germinal vesicle-stage oocytes.

The somatic type linker histone H1c is quickly replaced by H1oo in a donor nucleus transplanted into an oocyte. The greater mobility of H1oo when compared with H1c may contribute to the rapid replacement and increased instability of the embryonic chromatin structure.