ZFIN ID: ZDB-PUB-990824-26
Promoter activity of the zebrafish bhikhari retroelement requires an intact activin signaling pathway
Vogel, A.M. and Gerster, T.
Date: 1999
Source: Mechanisms of Development   85(1-2): 133-146 (Journal)
Registered Authors: Gerster, Thomas, Vogel, Andreas M.
Keywords: mesoderm induction; bhikhari; activin signaling pathway; retrotransposon; fibroblast growth factor
MeSH Terms:
  • Activins
  • Animals
  • Embryonic Induction/genetics
  • Gene Expression Regulation, Developmental*
  • Inhibins/genetics*
  • Mesoderm
  • Promoter Regions, Genetic*
  • Retroelements/genetics*
  • Zebrafish/embryology*
  • Zebrafish/genetics
PubMed: 10415354 Full text @ Mech. Dev.
We have investigated mesoderm induction in zebrafish employing the zebrafish LTR-retroelement bhikhari (bik). bik elements are transcribed in all early mesendodermal cells. This expression pattern is generated by a promoter located in the U3 region of the LTR. We show that bik is activated through the activin/Vg1 signaling pathway in an immediate early fashion. This activation critically depends on a sequence motif that occurs among others also in the Xenopus Mix2 activin response element (ARE). It has been shown that the Mix2 ARE binds FAST- 1, which complexes with Smad proteins to form a multi-protein complex. We confirm that also the bik ARE can be bound by FAST-1 in vitro. In animal cap experiments we demonstrate that this binding site is required for activin-induced transcriptional activation mediated by FAST and Smad-type proteins.