A Scan for Human-Specific Relaxation of Negative Selection Reveals Unexpected Polymorphism in Proteasome Genes

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Somel M., Sayres M. A. W., Jordan G., Huerta-Sanchez E., Fumagalli M., Ferrer-Admetlla A., ...Daha Fazla

MOLECULAR BIOLOGY AND EVOLUTION, cilt.30, sa.8, ss.1808-1815, 2013 (SCI-Expanded) identifier identifier identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 30 Sayı: 8
  • Basım Tarihi: 2013
  • Doi Numarası: 10.1093/molbev/mst098
  • Dergi Adı: MOLECULAR BIOLOGY AND EVOLUTION
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Sayfa Sayıları: ss.1808-1815
  • Anahtar Kelimeler: relaxation of constraints, human evolution, negative selection, olfactory transduction, proteasome, OLFACTORY RECEPTOR GENES, DEPENDENT PROTEOLYSIS, PURIFYING SELECTION, DIETARY-PROTEIN, EVOLUTION, SEQUENCE, GENOME, SUBSTITUTION, INHIBITION, DIVERGENCE
  • Orta Doğu Teknik Üniversitesi Adresli: Evet

Özet

Environmental or genomic changes during evolution can relax negative selection pressure on specific loci, permitting high frequency polymorphisms at previously conserved sites. Here, we jointly analyze population genomic and comparative genomic data to search for functional processes showing relaxed negative selection specifically in the human lineage, whereas remaining evolutionarily conserved in other mammals. Consistent with previous studies, we find that olfactory receptor genes display such a signature of relaxation in humans. Intriguingly, proteasome genes also show a prominent signal of human-specific relaxation: multiple proteasome subunits, including four members of the catalytic core particle, contain high frequency nonsynonymous polymorphisms at sites conserved across mammals. Chimpanzee proteasome genes do not display a similar trend. Human proteasome genes also bear no evidence of recent positive or balancing selection. These results suggest human-specific relaxation of negative selection in proteasome subunits; the exact biological causes, however, remain unknown.