Evolutionary analysis of the well characterized endo16 promoter reveals substantial variation within functional sites.

Published

Journal Article

The evolutionary mechanisms that operate on genetic variation within transcriptional regulatory sequences are not well understood. We present here an evolutionary analysis of an exceptionally well characterized cis-regulatory region, the endo16 promoter of the purple sea urchin. Segregating variation reveals striking differences in the intensity of negative selection among regulatory modules, reflecting their distinct functional roles. Surprisingly, transcription-factor-binding sites are as polymorphic and as likely to contain fixed differences as flanking nucleotides. Whereas nucleotides in protein-binding sites in the most proximal regulatory module exhibit reduced variation, those in other modules tend to be more polymorphic than putatively nonfunctional nucleotides. Two unrelated large insertions at the same position within the promoter are segregating at low frequencies; one is a strong ectodermal repressor that contains 16 verified transcription-factor-binding sites. These results demonstrate that a simple relationship between conservation and function does not exist within this cis-regulatory region and highlight significant population heterogeneity in the fine structure of a well understood promoter.

Full Text

Duke Authors

Cited Authors

  • Balhoff, JP; Wray, GA

Published Date

  • June 3, 2005

Published In

Volume / Issue

  • 102 / 24

Start / End Page

  • 8591 - 8596

PubMed ID

  • 15937122

Pubmed Central ID

  • 15937122

Electronic International Standard Serial Number (EISSN)

  • 1091-6490

International Standard Serial Number (ISSN)

  • 0027-8424

Digital Object Identifier (DOI)

  • 10.1073/pnas.0409638102

Language

  • eng