Tissue-specific transgenic, conditional knockout and knock-in mice of genes in the canonical Wnt signaling pathway.

The Wnt signaling pathway plays key roles in the development and homeostasis of a number of organs such as the brain, lung, liver, heart, gastrointestinal tract, mammary gland, skin, and bone, as well as of the immune system. Studies on conventional knockout mice of the genes in the Wnt signaling pathway have revealed its essential roles in these tissues; however, most of these knockout mice die during embryogenesis or soon after birth. Through more advanced techniques such as Cre/loxP and tetracycline-inducible systems, a gene of interest can be expressed or inactivated in a tissue-specific and time-controlled manner. Here we review recent papers on the tissue-specific transgenic, conditional knockout and knock-in mice of the genes in the Wnt signaling pathway In addition to such engineered mice, we also list reporter mice that have been generated to determine the activity of the canonical Wnt signaling pathway in mouse tissues.