|ZFIN ID: ZDB-PUB-030815-2|
Zygote Arrest 1 (Zar1) Is an Evolutionarily Conserved Gene Expressed in Vertebrate Ovaries
Wu, X., Wang, P., Brown, C.A., Zilinski, C.A., and Matzuk, M.M.
|Source:||Biology of reproduction 69(3): 861-867 (Journal)|
|Registered Authors:||Brown, Christopher|
|PubMed:||12773403 Full text @ Biol. Reprod.|
Wu, X., Wang, P., Brown, C.A., Zilinski, C.A., and Matzuk, M.M. (2003) Zygote Arrest 1 (Zar1) Is an Evolutionarily Conserved Gene Expressed in Vertebrate Ovaries. Biology of reproduction. 69(3):861-867.
ABSTRACTZAR1 (Zygote Arrest 1) is an ovary-specific maternal factor that plays essential roles during the oocyte-to-embryo transition. In mice, the Zar1 mRNA is detected as a 1.4kb transcript that is synthesized exclusively in growing oocytes. To further understand the functions of ZAR1, we have cloned the orthologous Zar1 cDNA and/or genes for mouse, rat, human, frog, zebrafish, and pufferfish. The entire mouse Zar1 gene and a related pseudogene span approximately 4.0kb, contain four exons, and map to adjacent loci on mouse chromosome 5. The human ZAR1 orthologous gene similarly consists of 4 exons and resides on human chromosome 4p12 which is syntenic with the mouse Zar1 chromosomal locus. Rat (Rattus norvegicus) and pufferfish (Fugu rubripes) Zar1 genes were recognized by database mining and deduced protein alignment analysis. The rat Zar1 gene also maps to a region syntenic with the mouse Zar1 gene locus on rat chromosome 14. Frog (Xenopus laevis) and zebrafish (Danio rerio) Zar1 orthologs were cloned by RT-PCR and RACE analysis of ovary mRNA. Unlike mouse and human, the frog Zar1 is detected in multiple tissues including lung, muscle, and ovary. The Zar1 mRNA appears in the cytoplasm of oocytes, and persists until tailbud stage during frog embryogenesis. Mouse, rat, human, frog, zebrafish, and pufferfish Zar1 genes encode proteins of 361, 361, 424, 295, 329, and 320 amino acids respectively, and share 50.8-88.1% amino acids identity. There are regions of the N-termini of these ZAR1 orthologs which show high sequence identity among these various proteins. However, the C-terminal 103 amino acids of these proteins, encoded by exons 2-4, contains an atypical 8-cysteine Plant Homeo Domain (PHD) motif and is highly conserved, sharring 80.6-98.1% identity among these species. These findings suggest that the carboxyl-termini of these ZAR1 proteins contains an important functional domain that is conserved through vertebrate evolution and may be necessary for normal female reproduction in the transition from oocyte to embryonic life.