Strain Detail: Pippi mice

Pippi mice are transgenic mice expressing förster (or fluorescence) resonance energy transfer (FRET) biosensor Pippi-PI3,4P2 monitoring PI3,4P2 level on the plasma membrane under the control of CAG promoter in whole body. PI3,4P2 is produced when PIP3 produced by PI3 kinases is dephosphorylated, and activates lots of enzymes included PH domain. Especially, because it's known that PDK and Akt which are kinases regulating apoptosis and cell movement bind to both PIP3 and PI3,4P2, PI3,4P2 is often used as indicator of activation level for these molecle. It's possible to measure PI3,4P2 level spatially and temporally in fetal or adult various tissues by live imaging observation of this strain in the two-photon microscopy. This strain expects not only to analyze the signal transduction cascade in live animals, but also apply drug development such as the pharmacodynamic analysis targeting PI3K, because these mice are showed rich expression in primary cultured cells derived from various tissues. This biosensor expresses in plasma membrane. FRET biosensor generally can't use for fixed samples.

1. Kamioka Y, Sumiyama K, Mizuno R, Sakai Y, Hirata E, Kiyokawa E, and Matsuda M. (2012) Live imaging of protein kinase activities in transgenic mice expressing FRET biosensors. Cell Struct Funct 37(1):65-73. [PMID:22277578]