title: Unequal distribution of otx1 mRnas among cleavage stage blastomeres in the teleost, Leucopsarion petersii (shiro-uo).
abstract: The otx genes belong to the orthodenticle gene family and play important roles in anterior brain development in vertebrates. We isolated two cDNA sequences, one homologous to human and zebrafish otxl and another homologous to zebrafish otx3, from the teleost Leucopsarion petersii (shiro-uo), which belongs to the family of gobies in the Perciformes. During embryogenesis of shiro-uo, otx1 and otx3 were expressed in the fore- and mid-brain throughout development in a manner similar to that observed in other vertebrates so far studied. However, otx-1 mRNA was also present at earlier stages and we obtained unique results using in situ hybridization and RT-PCR analysis demonstrating that otx-1 signals showed a distinct increase in the upper blastomeres, but not in the lower blastomeres, at the 8-cell stage. These stronger signals were maintained in the animal pole blastomeres during the 16-cell to 64-cell stages, followed by a gradual decrease during blastula stages. Such unexpected unequal distribution of otx1 mRNA revealed that blastomeres at early cleavage stages already showed non-equivalence in the embryogenesis of shiro-uo.
authors.affiliation: Department of Marine Biology, Graduate School of Marine Science and Technology, Tokai University, Japan.
authors.forename: Mikiko
authors.initials: M
authors.lastname: Kamimoto
authors.forename: Tohru
authors.initials: T
authors.lastname: Suzuki
authors.forename: Mutsumi
authors.initials: M
authors.lastname: Ito
authors.forename: Akimitsu
authors.initials: A
authors.lastname: Miyake
authors.forename: Norio
authors.initials: N
authors.lastname: Nakatsuji
authors.forename: Takako
authors.initials: T
authors.lastname: Nakatsuji
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001757:Blastomeres / Q000166:cytology*; D001921:Brain / Q000196:embryology* / Q000378:metabolism; D017931:DNA Primers / Q000737:chemistry; D018076:DNA, Complementary / Q000378:metabolism; D018507:Gene Expression Regulation, Developmental; D018398:Homeodomain Proteins / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D017403:In Situ Hybridization; D008969:Molecular Sequence Data; D009419:Nerve Tissue Proteins / Q000235:genetics / Q000378:metabolism; D051857:Otx Transcription Factors; D010473:Perciformes / Q000196:embryology*; D010802:Phylogeny; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D017386:Sequence Homology, Amino Acid; D015398:Signal Transduction; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*; D015027:Zebrafish
chemical_list: D017931:DNA Primers; D018076:DNA, Complementary; D018398:Homeodomain Proteins; D009419:Nerve Tissue Proteins; D051857:Otx Transcription Factors; D012333:RNA, Messenger; D014157:Transcription Factors