Of the thousands of MHC allelic variants in nonhuman primates, we believe there is a much smaller number of "high value" alleles. We define these as alleles (or closely related, nearly identical alleles belonging to the same lineage) that:
- Are found in in at least 5% of animals from a population. It is difficult to design cohorts based on alleles found in less than 5% of animals.
- Have an average transcript abundance in blood of at least 3%. Many MHC genes are not transcribed or are transcribed at extremely low levels. We have shown that transcriptionally abundant MHC class I sequences preferentially restrict T cell responses, while no biological function has yet been associated with rare MHC transcripts. In the absence of a compelling rationale for studying these sequences, we believe it is appropriate to focus on transcriptionally abundant sequences.
- rhesus macaques