As Anne-Karina Perl, PhD, started her work on embryonic lung development, she established the pharmacokinetics of doxycycline application for the use of the tetracycline inducible lung specific gene expression formerly generated by Jay Tichelaar. She characterized in detail the onset and cellular localization of inducible gene expression during embryonic lung development (Perl et al.; Transgenic Res. 2002). The inducible system overcomes embryonic and adult lethality and systemic effects and opened the field to study any genes during embryonic development and in adult lung injury models. These transgenic mouse lines, SPCrtTA (SftpC rtTA line 1) and CCSPrtTA (Scgb1a1 line 1), are now used by more than a hundred researchers all over the world to activate genes in the lung epithelium of embryonic and adult mice.

To establish inducible tissue specific gene inactivation, Perl crossed the SPCrtTA activator line 1 with operator mice expressing the Cre recombinase and characterized extend and cellular localization of recombination events with the Z / AP reporter line, which expresses alkaline phosphatase (AP) only in cells after recombination (Fig.1) (Perl et al.; PNAS 2002).

The tetracycline inducible gene inactivation in the lung epithelium has since successfully been used to discover new aspects of many gene functions in lung development and lung maturation and is now widely used in murine lung research. We characterized recombination with the CCSPrtTA activator line 1 (Perl et al.; Am J Respir Cell Mol Biol. 2005). Using the CCSPrtTA line targets recombination to the trachea, bronchi, bronchioles and a subset of alveolar type II cells (Fig. 2 and 3). GFP labeling of targeted cells revealed distinct cellular patterns in the trachea.

We recently finished the characterization of the CCSPrtTA activator line 2 (Perl et al. Am J Respir Crit Care Med. 2011). Useful comments about the strength and limitations of these mouse lines have been discussed in Perl AK, Zhang L, Whitsett JA, Am J Respir Cell Mol Biol. 2009, and in Whitsett JA, Perl AK. Am J Respir Cell Mol Biol. 2006.