Bessa, J., Tena, J.J., de la Calle-Mustienes, E., Fernández-Miñán, A., Naranjo, S., Fernández, A., Montoliu, L., Akalin, A., Lenhard, B., Casares, F., and Gómez-Skarmeta, J.L. (2009) Zebrafish enhancer detection (ZED) vector: A new tool to facilitate transgenesis and the functional analysis of cis-regulatory regions in zebrafish. Developmental dynamics : an official publication of the American Association of Anatomists. 238(9):2409-2417.
The identification and characterization of the regulatory activity of genomic sequences is crucial for understanding how the information contained in genomes is translated into cellular function. The cis-regulatory sequences control when, where, and how much genes are transcribed and can activate (enhancers) or repress (silencers) gene expression. Here, we describe a novel Tol2 transposon-based vector for assessing enhancer activity in the zebrafish (Danio rerio). This Zebrafish Enhancer Detector (ZED) vector harbors several key improvements, among them a sensitive and specific minimal promoter chosen for optimal enhancer activity detection, insulator sequences to shield the minimal promoter from position effects, and a positive control for transgenesis. Additionally, we demonstrate that highly conserved noncoding sequences homologous between humans and zebrafish largely with enhancer activity largely retain their tissue-specific enhancer activity during vertebrate evolution. More strikingly, insulator sequences from mouse and chicken, but not conserved in zebrafish, maintain their insulator capacity when tested in this model.