These Gpr116flox mutant mice possess loxP sites flanking exon 2, encoding the start codon, of the G protein-coupled receptor 116 (Gpr116). GPR116 is an endothelial cell specific transmembrane receptor. In addition to its pan endothelial expression Gpr116 is also expressed in lung Alveolar Type
II cells where it plays a critical role in lung surfactant homeostasis. Mice that are homozygous for this allele are viable and fertile. When bred to mice that express tissue-specific Cre recombinase, resulting offspring will have exon 2 deleted in the cre-expressing tissues.
For example, when bred to B6.Cg-Tg(Tek-cre)12Flv/J mice (Stock No. 004128) expressing Cre recombinase in endothelial cells, resulting offspring display labored breathing by 4 months of age, weigh less than littermates by 14 months, and have a shortened lifespan. They also have an accumulation of surfactant proteins in their lungs, and bronchoalveolar lavage fluid (BALF) has a milky appearance.
When bred to B6.Cg-Tg(SFTPC-rtTA)5Jaw/J and B6.Cg-Tg(tetO-cre)1Jaw/J mice (Stock No. 006235 and Stock No. 006234, respectively) express Cre recombinase in the developing and adult lung and respiratory epithelium, in the resulting doxycycline-treated offspring BALF has increased levels of surfactant proteins, cholesterol and phosphatidylcholine.
