Polymorphism among rDNA cistron (18S-5.8S-26S) and 5S ribosomal DNA copies in Asclepias syriaca. Non-zero proportions below the blue line are likely due to sequencing error. Proportions above the blue line likely represent polymorphism within or among rDNA arrays. The proportion of polymorphic sites for each rDNA region is given beneath the label.
Straub et al. BMC Genomics 2011 12:211 doi:10.1186/1471-2164-12-211