Multiple functions of a Zic-like gene in the differentiation of notochord, central nervous system and muscle in Ciona savignyi embryos.
Multiple functions of a Zic-like zinc finger transcription factor gene (Cs-ZicL) were identified in Ciona savignyi embryos. cDNA clones for Cs-ZicL, a beta-catenin downstream genes, were isolated and the gene was transiently expressed in the A-line notochord/nerve cord lineage and in B-line muscle lineage from the 32-cell stage and later in a-line CNS lineage from the 110-cell stage. Suppression of Cs-ZicL function with specific morpholino oligonucleotide indicated that Cs-ZicL is essential for the formation of A-line notochord cells but not of B-line notochord cells, essential for the CNS formation and essential for the maintenance of muscle differentiation. The expression of Cs-ZicL in the A-line cells is downstream of beta-catenin and a beta-catenin-target gene, Cs-FoxD, which is expressed in the endoderm cells from the 16-cell stage and is essential for the differentiation of notochord. In spite of its pivotal role in muscle specification, the expression of Cs-ZicL in the muscle precursors is independent of Cs-macho1, which is another Zic-like gene encoding a Ciona maternal muscle determinant, suggesting another genetic cascade for muscle specification independent of Cs-macho1. Cs-ZicL may provide a future experimental system to explore how the gene expression in multiple embryonic regions is controlled and how the single gene can perform different functions in multiple types of embryonic cells.
Imai
Kaoru S
KS
Department of Zoology, Graduate School of Science, Kyoto University, Sakyo-ku, 606-8502, Japan.
Satou
Yutaka
Y
Satoh
Nori
N
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D002454:Cell Differentiation; D018076:DNA, Complementary; D004625:Embryo, Nonmammalian / Q000502:physiology*; D018507:Gene Expression Regulation, Developmental; D051379:Mice; D008969:Molecular Sequence Data; D018482:Muscle, Skeletal / Q000166:cytology / Q000196:embryology*; D009420:Nervous System / Q000166:cytology / Q000196:embryology*; D009672:Notochord / Q000166:cytology*; D010802:Phylogeny; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D014157:Transcription Factors / Q000235:genetics*; D014561:Urochordata / Q000196:embryology*; D014981:Xenopus; D029867:Xenopus Proteins; D016335:Zinc Fingers
D018076:DNA, Complementary; D014157:Transcription Factors; D029867:Xenopus Proteins; C116546:Zic1 protein, Xenopus; C492122:Zic1 protein, mouse