Characterization of a novel Fibroblast growth factor 10 (Fgf10) knock-in mouse line to target mesenchymal progenitors during embryonic development

E El Agha; D Al Alam; G Carraro; B MacKenzie; K Goth; R Voswinckel; MK HajiHosseini; S Bellusci

doi:10.1055/s-0032-1315504

Pneumologie, Inhaltsverzeichnis

Characterization of a novel Fibroblast growth factor 10 (Fgf10) knock-in mouse line to target mesenchymal progenitors during embryonic development

E El Agha ¹, D Al Alam ², G Carraro ¹, B MacKenzie ¹, K Goth ¹, R Voswinckel ³, MK HajiHosseini ⁴, S Bellusci ¹^,²

¹Excellence Cluster Cardio-Pulmonary System (ECCPS), Member of the German Center for Lung Research, Universities of Gießen and Marburg Lung Center (UGMLC), Gießen
²Developmental Biology and Regenerative Medicine Program, Saban Research Institute of Childrens Hospital Los Angeles and University of Southern California, Los Angeles, California, USA
³Department for Lung Development and Remodelling, Member of the German Center for Lung Research, Max-Planck-Institute for Heart and Lung Research, Bad Nauheim
⁴School of Biological Sciences, University of East Anglia, Norwich, UK

Abstract

Fibroblast growth factor 10 (Fgf10) is a key player for branching morphogenesis in murine embryos. Fgf10-knockout mice suffer from lung and limb agenesis as well as cecal and colonic atresia and are thus not viable. To date, the Mlcv1v-nLacZ-24 transgenic mouse strain (often referred to as Fgf10LacZ), in which a LacZ cassette has been inserted within regulatory sequences 114 kb upstream of the endogenous Fgf10 gene, has been the only strain that allows transient lineage tracing of Fgf10-positive cells. Here, we describe a novel Fgf10Cre-ERT2 knock-in line (or simply Fgf10iCre) in which a Cre-ERT2-IRES-YFP cassette has been introduced in frame with the first ATG of exon 1 of the endogenous Fgf10 gene. Our studies show that the insertion of Cre-ERT2 has led to Fgf10 inactivation. By crossing the Fgf10iCre line with a Tomatoflox reporter strain, we demonstrate that Fgf10-positive cells are specifically labeled upon tamoxifen administration in many tissues both during development and postnatally. Moreover, we show that the Fgf10iCre line can be used for conditional gene inactivation in an inducible fashion during early developmental stages. We also provide evidence that transcription factors located in the first intron of Fgf10 gene are critical for maintaining Fgf10 expression over time.

Keywords: Fgf10iCre; Fgf10-positive cells; tamoxifen