Localization of c-mos mRNA around the animal pole in the zebrafish oocyte with Zor-1/Zorba.
In oocytes, many maternally supplied products are stored, and these products play important roles in cell cycle regulation and early development. Mos protein, which is coded on the c-mos gene, promotes oocyte maturation and is involved in MAP-kinase signaling pathway. In Xenopus, maternally supplied c-mos mRNA undergoes poly(A) addition, and translational activation via CPE (cytoplasmic polyadenylation element) and CPEB (CPE binding protein). The elongated poly(A) is shortened and the c-mos mRNA is degraded during early embryogenesis via EDEN (embryo deadenylation element) and EDEN-BP (EDEN-binding protein). We cloned the full-length zebrafish c-mos gene, which is conserved at the protein coding region in vertebrates. c-mos mRNA has two putative CPE sequences in its 3'UTR, which binds to zebrafish CPEB homologous protein, Zor-1. We could not observe EDEN sequence, and could not detect interaction between c-mos mRNA and zebrafish EDEN-BP homologous protein, Brul, even though immuno precipitation and RT-PCR experiments suggested that c-mos mRNA interacts with Zor-1 in vivo. Interestingly, we found c-mos mRNA is located in the animal cortex of zebrafish oocyte, where Zor-1 protein exists. Taken together, these results suggest that the animal cortex is the central core of oocyte maturation in zebrafish.
Suzuki
Hitoshi
H
Center for Nano Materials and Technology, Japan Advanced Institute of Science and Technology, Ishikawa, Japan. suzuki-h@jaist.ac.jp
Tsukahara
Toshifumi
T
Inoue
Kunio
K
D000818:Animals; D015152:Blotting, Northern; D016764:Cell Polarity / Q000502:physiology; D003001:Cloning, Molecular; D017931:DNA Primers / Q000235:genetics; D018076:DNA, Complementary / Q000235:genetics; D016258:Genes, mos / Q000235:genetics*; D047468:Immunoprecipitation; D017403:In Situ Hybridization; D009865:Oocytes / Q000166:cytology / Q000378:metabolism*; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism*; D016601:RNA-Binding Proteins / Q000378:metabolism*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D015027:Zebrafish / Q000196:embryology*; D029961:Zebrafish Proteins / Q000378:metabolism*
D017931:DNA Primers; D018076:DNA, Complementary; D012333:RNA, Messenger; D016601:RNA-Binding Proteins; D029961:Zebrafish Proteins; C116678:cpeb1b protein, zebrafish