Transplantation of mouse embryo fibroblasts: an approach to study the physiological pathways linking the suprachiasmatic nucleus and peripheral clocks.

One of the unresolved issues in the field of circadian biology is dissection of the communication pathways between central and peripheral oscillators. We have developed an experimental procedure in which an implant of mouse embryo fibroblasts of a specific genotype can be successfully grafted into a host animal of a different genotype. This methodology provides an excellent tool to study how peripheral clocks are entrained under various physiological settings and the contribution of individual signaling effectors in this process.