Fig. 3From: Evidence of metachronous development of ovarian teratomas: a case report of bilateral mature cystic teratomas of the ovaries and systematic literature reviewMethylation statuses of the bilateral mature cystic teratomas of the ovaries during oogenesis. As an ovum develops in the ovary its paternal methylation is erased. The primary oocyte presents at birth and the secondary oocyte is the stage released by the ovary during ovulation. Primary oocyte production begins before birth and is indicated by shadingBack to article page