An additional feature of balanced polymorphisms is an excess of diversity, but this is expected only in the case of long-standing selection, i.e. longer than 4Ne generations.
The president, however, is said to be in a fighting mood after his re-election, and generally prefers to promote loyal lieutenants of long standing, like Mr Lew.The selection of Ms Rice as secretary of state would also spark a row.
Fully significant results were obtained in all LRT (data not shown), indicating that the positive selection signal at OAS1 is not merely accounted for by the long-standing balancing selection event in hominids.
Overall, these analyses indicate that the IFI16 region has been a target of long-standing balancing selection.
Indeed, long-standing balancing selection at the CAPN10 locus, also involved in insulin secretion and action [ 76], has previously been demonstrated [ 77].
Since such mutations run counter to long-standing stabilizing selection acting upon Msx, they are likely to have deleterious phenotypic consequences.
In this case, although celiac disease presents early in life, the widespread use of gluten-containing foods has likely appeared too recently in human populations to account for the long-standing balancing selection signature we describe herein.
An interesting observation emerging from the population genetics phylogenetics analysis is that results were consistent with the long-standing balancing selection scenario that was previously described at the OAS1 locus in hominids (Ferguson et al. 2012).
Two genes encoding ER aminopeptidases that trim peptides translocated by TAP have recently been shown to be subjected to long-standing balancing selection with polymorphic variants conferring resistance against HIV-1 [ 26].
Interestingly, most of these OAS1 sites were previously shown to define two major haplotype clades that segregate in chimpanzees and are maintained by long-standing balancing selection (Ferguson et al. 2012) (table 2).
Population genetic analysis in humans revealed that an IFI16 genic region has been a target of long-standing balancing selection, possibly acting on two nonsynonymous polymorphisms located in the spacer region.
