Nuclear Magnetic Reporters

With the advantage of tomographical data set and detailed anatomical information, magnetic resonance imaging (MRI) features an unsurpassed space resolution (micrometers!) in the field of in vivo imaging. Conversely, imaging of optical reporters like luciferase and GFP, still suffers from short-sighted resolution, often requiring longer post-mortem analysis (i.e. microscopy-slides) to identify and deconvolve photon emission sources from in vivo datasets. From this "topological" standpoint it is easy to understand the growing awareness and demand of new 'super-paramagnetic"'' reporter genes to be detected according to their 'relaxivity'. NMR gene expression strategies thus far introduced in recent literature include:
  • detection of beta-galactosidase activity;
  • targeting of amide protons of expressed proteins;
  • expression of natural iron homeostasis proteins such as transferrin, ferritin, MagA.
Nonetheless, those "magnetic" papers had very low followup, and a transgenic paramagnetic reporter mouse still doesn't exists. MRI reporters classically suffer from low sensitivity (lot of reporter need to be expressed in order to be detected) and low dynamic range (the detection doesn't discriminate very well different reporter concentrations). It is possible to conceive a reporter gene with high space/time resolution, high sensitivity and high linear range? With multimodality imaging a super reporter mouse can harbor a vector containing more than one reporter (for different imaging modalities). This is very attractive for lab leaders in imaging techs, and lot of cut and paste have been made with reporter sequences. Do you know any super-mouse?