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SUMMARY:Genetic mechanisms of transcription factor binding evolution in fi
 ve vertebrates
DTSTART:20091125T161500
DTSTAMP:20260506T194856Z
UID:d92bb69d2215f8bba7d3faf629965405fb81607124c5e564190a1766
CATEGORIES:Conferences - Seminars
DESCRIPTION:Benoît Ballester\, EBI\nThe molecular mechanisms that drive t
 he rapid evolution of mammalian transcription factor binding are largely u
 nknown. We experimentally determined the genome-wide binding of the protot
 ypical CCAAT/enhancer-binding protein alpha (CEBPA) in the livers of macaq
 ue\, dog\, mouse\, opossum\, and chicken\, and then computationally dissec
 ted the underlying sequence changes that redirect transcription factor bin
 ding in each lineage. Despite our finding that the number of binding event
 s tracks closely with genome size\, the vast majority are unique to each v
 ertebrate species. The lineage-specific absences of transcription factor b
 inding events were largely attributable to losses of the canonical sequenc
 e motif by indels and base pair changes. Similarly\, the lineage-specific 
 gains were driven by the creation of novel motifs by indels and base pair 
 substitutions\, but also by expansions in novel species-specific sequences
  often containing repetitive elements. Based on genomic proximity\, transc
 ription factor gains rarely serve as turnovers to potentially recover abse
 nt binding events\, indicating that most binding events are transcriptiona
 lly neutral and therefore dispensable for core regulator function. The rap
 id and extensive remodelling of the interactions between transcription fac
 tors and potentially regulatory genetic sequence would therefore appear to
  be an ideal substrate for natural selection.
LOCATION:AI 1153 https://plan.epfl.ch/?room==AI%201153
STATUS:CONFIRMED
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