Zebrafish sp7:EGFP: A Transgenic for Studying Otic Vesicle Formation, Skeletogenesis, and Bone Regeneration

We report the expression pattern and construction of a transgenic zebrafish line for a transcription factor involved in otic vesicle formation and skeletogenesis. The zinc finger transcription factor sp7 (formerly called osterix) is reported as a marker of osteoblasts. Using bacterial artificial chromosome (BAC)-mediated transgenesis, we generated a zebrafish transgenic line for studying skeletal development, Tg(sp7:EGFP)b1212. Using a zebrafish BAC, EGFP was introduced downstream of the regulatory regions of sp7 and injected into one cell-stage embryos. In this transgenic line, GFP expression reproduces endogenous sp7 gene expression in the otic placode and vesicle, and in forming skeletal structures. GFP-positive cells were also detected in adult fish, and were found associated with regenerating fin rays postamputation. This line provides an essential tool for the further study of zebrafish otic vesicle formation and the development and regeneration of the skeleton. genesis 48:505-511,2010. (C) 2010 Wiley-Liss, Inc.