Genetic mechanisms of transcription factor binding evolution in five vertebrates
Event details
| Date | 25.11.2009 |
| Hour | 16:15 |
| Speaker | Benoît Ballester, EBI |
| Location | |
| Category | Conferences - Seminars |
The molecular mechanisms that drive the rapid evolution of mammalian transcription factor binding are largely unknown. We experimentally determined the genome-wide binding of the prototypical CCAAT/enhancer-binding protein alpha (CEBPA) in the livers of macaque, dog, mouse, opossum, and chicken, and then computationally dissected the underlying sequence changes that redirect transcription factor binding in each lineage. Despite our finding that the number of binding events tracks closely with genome size, the vast majority are unique to each vertebrate species. The lineage-specific absences of transcription factor binding events were largely attributable to losses of the canonical sequence 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, transcription factor gains rarely serve as turnovers to potentially recover absent binding events, indicating that most binding events are transcriptionally neutral and therefore dispensable for core regulator function. The rapid and extensive remodelling of the interactions between transcription factors and potentially regulatory genetic sequence would therefore appear to be an ideal substrate for natural selection.
Practical information
- General public
- Free
Contact
- Jacques Rougemont