Generation of a new Paneth Cell specific Cre recombinase transgenic mouse line

Natalia Garcia-Gonzalez^1,2Charlotte Wallaeys^1,2Wendy Toussaint^1,2Tino Hochepied^1,2Sylviane Dewaele^1,2Somara De Beul^1,2Steven Timmermans^1,2Claude Libert^1,2*

• ¹Center for Inflammation Research, Flanders Institute for Biotechnology, Ghent, East Flanders, Belgium
• ²Department of Biomedical Molecular Biology, Ghent University, Gent, Belgium

Paneth cells are located in the crypts of Lieberkühn in mammalian small intestines and are producing antimicrobial peptides to keep the microbiome under control. The genetic manipulation of Paneth cells, their tracking and depletion depends on a solid Paneth cell specific Cre transgenic line. Here we describe bulk RNAseq-based expression data from pure, sorted Paneth cells of C57BL/6J mice, and identify several strongly expressed Paneth cell specific genes, the expression of which is stable under pathophysiological conditions, as well as in duodenum, jejunum and ileum. We selected the Defa24 gene regulatory sequences and generated a new Defa24iCre transgenic line using BAC technology, Tg(Defa24-icre)Cli. The resulting transgenic line provides robust expression and allows for the complete depletion of Paneth cells by cell ablation, yielding mice without any detectable lysozyme biological activity in the small intestines.