Relative abundance tRNA isoacceptor families located consecutively within tRNA clusters. Four data points are shown for each combination of amino acids: Top: pairs in the same reading direction; below: pairs in opposite reading direction. Left: pairs of presumably functional tRNA, right: pairs of tRNA pseudogenes. The last three rows and columns refer to putative Suppressor, SeC, and tRNA pseudogenes of undetermined isoacceptor class, resp.
Bermudez-Santana et al. BMC Genomics 2010 11:270 doi:10.1186/1471-2164-11-270