ZAP-1 DNA binding activity is first detected at the onset of zona pellucida gene expression in embryonic mouse oocytes.

ZAP-1 (zona pellucida gene activating protein-1) is a putative transcription factor controlling the oocyte-specific expression of mouse and human zona pellucida genes. The DNA binding activity of ZAP-1 first appears in oocytes from 19-day-old mouse embryos and reaches a maximum level at 10 days after birth. This developmental profile closely parallels that of mouse zona pellucida gene transcription, which is detected in oocytes at 19 days of fetal life using a sensitive RT-PCR method and is maximal in 10-day-old animals. DNA binding activity similar to that of ZAP-1 is present in ovarian extracts from rat, human, and opossum, suggesting that the ZAP-1 protein may be conserved among mammals.