A lens-specific co-injection marker for medaka transgenesis.

Recent advances in generating transgenic fish have improved the efficiency of germline transmission and enabled the generation of large numbers of transgenic animals. A suitable co-injection marker may help facilitate the preselection of transgenic embryos. For this purpose, a lens-specific marker appears to be a suitable candidate since the lens is a well-defined tissue that is easily accessible for examination of reporter gene expression. We constructed reporter vectors including the mouse gamma-F crystallin (mgammaF-Cry) promoter, which drives high levels of lens-specific heterologous expression of the reporter gene and thereby enables easy sorting of transgenic fish.