Signature Sequences: unique to certain group of organisms Applications: Phylogenetic Probes Table 18. 1 Signature sequences from 16S or 18S rRNA defining the three domains of living organisms Occurrence among Oligonucleotide sequencea pproximate position Archaea Bacteria Eukarya CACYYG 315 0 CYAAYUNYG 510 AAACUCAAA 910 100 AACUUAAAG 910 100 NUUAAUBCG 60 >95 0 YUYAABUG 000 100 CAACCYYCR 1110 >95 UUCCCG LCCCUG 05 100 CUCEUUG 0 UACAC 1400 0 99 100 100 Y=amy pyrmidine R any purine N any purine or pyrimidine Refer to Figure 18. 7 for numbering scheme of 16S, RNA Occurrence refers to percentage of organisms examnined in any domain.Signature Sequences: unique to certain group of organisms Applications: Phylogenetic Probes