Some junk ain't junk

Well, about 3% of it anyways. Maybe.
.........

Nature Genetics 38, 223 - 227 (2005)
Conserved noncoding sequences are selectively constrained and not mutation cold spots
Joel N Hirschhorn et al.

Abstract:
Noncoding genetic variants are likely to influence human
biology and disease, but recognizing functional noncoding
variants is difficult. Approximately 3% of noncoding sequence
is conserved among distantly related mammals, suggesting that
these evolutionarily conserved noncoding regions (CNCs) are
selectively constrained and contain functional variation.
However, CNCs could also merely represent regions with lower
local mutation rates. Here we address this issue and show
that CNCs are selectively constrained in humans by analyzing
HapMap genotype data. Specifically, new (derived) alleles of
SNPs within CNCs are rarer than new alleles in nonconserved
regions (P = 3 10-18), indicating that evolutionary pressure
has suppressed CNC-derived allele frequencies. Intronic CNCs
and CNCs near genes show greater allele frequency shifts, with
magnitudes comparable to those for missense variants. Thus,
conserved noncoding variants are more likely to be functional.
Allele frequency distributions highlight selectively constrained
genomic regions that should be intensively surveyed for
functionally important variation.


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Relevant Pages

  • Paper: Conserved noncoding sequences are selectively constrained and not mutation cold spots
    ... Conserved noncoding sequences are selectively constrained and not mutation ... but recognizing functional noncoding variants is difficult. ... CNCs could also merely represent regions with lower local mutation ... genes show greater allele frequency shifts, ...
    (sci.bio.evolution)
  • Re: Some junk aint junk
    ... > Conserved noncoding sequences are selectively constrained and not mutation ... I would submit that electronics "gates" and cascades of ... among distantly related mammals. ... conserved noncoding regions (CNCs) are selectively constrained... ...
    (sci.bio.evolution)