Zygote arrest 1 (Zar1) is a novel maternal-effect gene critical for the oocyte-to-embryo transition.
Document Type
Article
Publication Date
2003
Keywords
Animal, Blotting-Northern, Blotting-Southern, Blotting-Western, Cloning-Molecular, Comparative-Study, DNA-Replication, Egg-Proteins, Embryo, Female, Fertility, Fertilization-in-Vitro, Gene-Expression-Regulation, Gene-Library, Goats, In-Vitro, Meiosis, Mice, Mice-Inbred-C57BL, Molecular-Sequence-Data, Oocytes, Pregnancy, RNA-Messenger, Reverse-Transcriptase-Polymerase-Chain-Reaction, Sequence-Homology-Amino-Acid, Spermatids, Stem-Cells, SUPPORT-NON-U-S-GOVT, SUPPORT-U-S-GOVT-P-H-S, Zygote
First Page
187
Last Page
191
JAX Source
Nat Genet 2003 Feb; 33(2):187-191.
Abstract
The female gamete (the oocyte) serves the distinct purpose of transmitting the maternal genome and other maternal factors that are critical for post-ovulation events. Through the identification and characterization of oocyte-specific factors, we are beginning to appreciate the diverse functions of oocytes in ovarian folliculogenesis, fertilization and embryogenesis. To understand these processes further, we identified genes called zygote arrest 1 (Zar1 and ZAR1 in mouse and human, respectively) as novel oocyte-specific genes. These encode proteins of 361 amino acids and 424 amino acids, respectively, which share 59% amino-acid identity and an atypical plant homeo-domain (PHD) motif. Although Zar1-null (Zar1(-/-)) mice are viable and grossly normal, Zar1(-/-) females are infertile. Ovarian development and oogenesis through the early stages of fertilization are evidently unimpaired, but most embryos from Zar1(-/-) females arrest at the one-cell stage. Distinct pronuclei form and DNA replication initiates, but the maternal and paternal genomes remain separate in arrested zygotes. Fewer than 20% of the embryos derived from Zar1(-/-) females progress to the two-cell stage and show marked reduction in the synthesis of the transcription-requiring complex, and no embryos develop to the four-cell stage. Thus, Zar1 is the first identified oocyte-specific maternal-effect gene that functions at the oocyte-to-embryo transition and, as such, offers new insights into the initiation of embryonic development and fertility control in mammals.
Recommended Citation
Wu X,
Viveiros MM,
Eppig JJ,
Bai Y,
Fitzpatrick SL,
Matzuk MM.
Zygote arrest 1 (Zar1) is a novel maternal-effect gene critical for the oocyte-to-embryo transition. Nat Genet 2003 Feb; 33(2):187-191.