ZAR1 Background Information Oocytes are female gametes that are critical in postovulation events such as ovarian folliculogenesis, fertilization and embryogenesis. ZAR1 (zygote arrest 1) is an oocyte-specific maternal effect factor that is localized to the cytoplasm and is expressed in ovary and testis. Essential in the oocyte-to-embryo transition, ZAR1 is an evolutionary conserved protein that is responsible for female fertility and may play a role in transcriptional regulation. In mice, null expression of ZAR1 results in infertility, suggesting that ZAR1 plays a key role in both the initiation of embryonic development and in fertility control in mammals. ZAR1 is 424 amino acids in length and, like its mouse homolog, has an atypical PHD motif at its C-terminus.
