Identification of downstream genes of the ascidian muscle determinant gene Ci-macho1

Dev Biol. 2004 Oct 15;274(2):478-89. doi: 10.1016/j.ydbio.2004.07.013.


Autonomous differentiation of primary muscle cells in ascidian embryos is triggered by a maternal determinant recently identified as the macho-1 gene. macho-1 encodes a transcription factor of the Zic family with five C2H2 zinc-finger motifs. In the present study, we firstly performed a screen, using a quantitative PCR method, of genes encoding transcription factors and components in major signaling pathways to identify those regulated downstream of Ci-macho1 in early embryos of Ciona intestinalis. The amount of transcripts for a total of 64 genes was altered at the 32-cell stage depending on the Ci-macho1 activity level. Whole-mount in situ hybridization assays revealed that the alteration of expression for at least 13 of them was adequately visualized to confirm the results of quantitative PCR. Second, we determined a possible binding sequence of Ciona macho1. macho1 recombinant proteins of both C. intestinalis and Ciona savignyi recognized a sequence, 5'-GCCCCCCGCTG-3', that resembles the mammalian Zic binding site. In addition, most of the genes identified as potential Ci-macho1 downstream genes, in particular Ci-Tbx6b and Ci-snail, possessed plausible Ci-macho1-binding sequences in their 5' upstream region, suggesting their direct activation by Ci-macho1. Furthermore, some of the genes including three Wnt genes noted in the quantitative analyses implied that Ci-macho1 is involved in the differentiation of endoderm and mesenchyme via intracellular communications.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Base Sequence
  • Cell Differentiation
  • Ciona intestinalis / anatomy & histology
  • Ciona intestinalis / embryology*
  • Ciona intestinalis / genetics*
  • Ciona intestinalis / metabolism
  • Gene Expression Profiling
  • Gene Expression Regulation, Developmental*
  • In Situ Hybridization
  • Muscles / embryology*
  • Muscles / physiology
  • Oligonucleotides, Antisense / genetics
  • Oligonucleotides, Antisense / metabolism
  • RNA, Messenger / genetics
  • RNA, Messenger / metabolism
  • Recombinant Fusion Proteins / genetics
  • Recombinant Fusion Proteins / metabolism
  • Signal Transduction / physiology
  • Transcription Factors / genetics
  • Transcription Factors / metabolism*
  • Zinc Fingers


  • Oligonucleotides, Antisense
  • RNA, Messenger
  • Recombinant Fusion Proteins
  • Transcription Factors