"Phenomics" is the study of the range of variation in measurable traits, or "phenotypes," within a species. The best way to study this is by the systematic comparison of inbred strains, in which repeated brother-sister matings have resulted in the loss of all heterozygosity. Essentially, inbred mice are clones of each other, identical at every nucleotide (except for rare new mutations). The Pain Genetics Lab has conducted, and continues to conduct, the most comprehensive phenomics project of pain-related traits, in the following set of 12 inbred mouse strains: 129/P3J, A/J, AKR/J, BALB/cJ, C3H/HeJ, C57BL/6J, C57BL/10J, C58/J, CBA/J, DBA/2J, RIIIS/J, SM/J. By examining genetic correlations among the responses, to different types of pain and different analgesic modalities, of this set of mouse strains, we have been able to glean a number of interesting facts about pain. It appears, for example, that there are at least five fundamental "types" of pain as defined by genetic correlation: 1) thermal, 2) chemical/inflammatory, 3) mechanical hypersensitivity, 4) thermal hypersensitivity (non-afferent-dependent), and 5) thermal hypersensitivity (afferent-dependent). We were the first to show a genetic relationship between pain sensitivity and response to analgesics (the more sensitive a mouse is to pain, the more resistant it is to inhibition of that pain by analgesics, and vice-versa), a finding that has been recently shown to be true in people as well.
To see our results compared to those of other phenomic projects, see the Mouse Phenome Database.
