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

ABSTRACT: 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

SUBMITTER: Balhoff JP 

PROVIDER: S-EPMC1150811 | biostudies-literature | 2005 Jun

REPOSITORIES: biostudies-literature