Conserved noncoding sequences (CNSs) in higher plants
Michael Freelinga, E-mail The Corresponding Author and Shabarinath
Subramaniama
Plant conserved noncoding sequences (CNSs)—a specific category of
phylogenetic footprint—have been shown experimentally to function. No
plant CNS is conserved to the extent that ultraconserved noncoding
sequences are conserved in vertebrates. Plant CNSs are enriched in known
transcription factor or other cis-acting binding sites, and are usually
clustered around genes. Genes that encode transcription factors and/or
those that respond to stimuli are particularly CNS-rich. Only rarely
could this function involve small RNA binding. Some transcribed CNSs
encode short translation products as a form of negative control.
Approximately 4% of Arabidopsis gene content is estimated to be both
CNS-rich and occupies a relatively long stretch of chromosome: Bigfoot
genes (long phylogenetic footprints). We discuss a ‘DNA-templated
protein assembly’ idea that might help explain Bigfoot gene CNSs.
