The evolutionarily conserved leprecan gene: Its regulation by Brachyury and its role in the developing Ciona notochord

Matthew P. Dunn, Anna Di Gregorio

Research output: Contribution to journalArticle

Abstract

In Ciona intestinalis, leprecan was identified as a target of the notochord-specific transcription factor Ciona Brachyury (Ci-Bra) (Takahashi, H., Hotta, K., Erives, A., Di Gregorio, A., Zeller, R.W., Levine, M., Satoh, N., 1999. Brachyury downstream notochord differentiation in the ascidian embryo. Genes Dev. 13, 1519-1523). By screening ∼ 14 kb of the Ci-leprecan locus for cis-regulatory activity, we have identified a 581-bp minimal notochord-specific cis-regulatory module (CRM) whose activity depends upon T-box binding sites located at the 3′-end of its sequence. These sites are specifically bound in vitro by a GST-Ci-Bra fusion protein, and mutations that abolish binding in vitro result in loss or decrease of regulatory activity in vivo. Serial deletions of the 581-bp notochord CRM revealed that this sequence is also able to direct expression in muscle cells through the same T-box sites that are utilized by Ci-Bra in the notochord, which are also bound in vitro by the muscle-specific T-box activators Ci-Tbx6b and Ci-Tbx6c. Additionally, we created plasmids aimed to interfere with the function of Ci-leprecan and categorized the resulting phenotypes, which consist of variable dislocations of notochord cells along the anterior-posterior axis. Together, these observations provide mechanistic insights generally applicable to T-box transcription factors and their target sequences, as well as a first set of clues on the function of Leprecan in early chordate development.

Original languageEnglish (US)
Pages (from-to)561-574
Number of pages14
JournalDevelopmental Biology
Volume328
Issue number2
DOIs
StatePublished - Apr 15 2009

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Keywords

  • Ascidian
  • Brachyury
  • Ciona
  • Leprecan
  • Muscle
  • Notochord
  • Prolyl 3-hydroxylase
  • T-box
  • Tbx6
  • cis-Regulation

ASJC Scopus subject areas

  • Molecular Biology
  • Developmental Biology
  • Cell Biology

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