Abstract
Abstract: :
Purpose: We have made use of a novel mouse strain carrying Cre whose expression is controlled by a tissue–specific promoter (kerotocan) which can be used to determine the fates of periocular mesenchymal cells during embryonic development. Methods: To create a transgenic mouse line, a gene construct containing keratocan promoter and Cre recombinase minigene was microinjected into the fertilized mouse eggs. We then crossed these mice to Z/EG (EGFP) and ROSA26–LacZ reporter strains to reveal the fates of Cre expressing cells in situ. The Cre activity was assessed by the detection of green fluorescence and the ß–galactosidase activity of bi–transgenic Kera–Cre/ZEG and Kera–Cre/Rosa26–LacZ mice, respectively. Results: Twenty two independent transgenic mouse lines were obtained. Seven founders did not transmit the transgene to its offspring. Four mouse lines did not express the Cre activity. The rest of mouse lines were examined further. We detected strong lacZ expression in corneal stroma of the Kera–Cre/Rosa26–LacZ bi–transgenic mice and green fluorescence in the corneal stroma of the Kera–Cre/ Z/EG bi–transgenic mice. However, we also observed that the lack of the ß–galactosidase and green fluorescence in the corneal endothelium and limbal region of the corneal stroma. Interesting, through whole body survey, LacZ expression was detected not only in the corneal stroma, but also in the CA1 and CA2 region of the hippocampus Conclusions: Kera–Cre transgenic mice are a new genetic tool for the analyses of neural–crest cell lineage and tissue–specific gene targeting.
Keywords: cornea: stroma and keratocytes • gene/expression • transgenics/knock-outs