title: How old are RNA networks?
abstract: Some major classes of RNAs (such as mRNA, rRNA, tRNA and RNase P) are ubiquitous in all living systems so are inferred to have arisen early during the origin of life. However, the situation is not so clear for the system of RNA regulatory networks that continue to be uncovered, especially in eukaryotes. It is increasingly being recognised that networks of small RNAs are important for regulation in all cells, but it is not certain whether the origin of these networks are as old as rRNAs and tRNA. Another group of ncRNAs, including snoRNAs, occurs mainly in archaea and eukaryotes and their ultimate origin is less certain, although perhaps the simplest hypothesis is that they were present in earlier stages of life and were lost from bacteria. Some RNA networks may trace back to an early stage when there was just RNA and proteins, the RNP-world; before DNA.
authors.affiliation: Allan Wilson Centre of Molecular Ecology and Evolution, Massey University, Palmerston North, New Zealand.
authors.forename: Toni
authors.initials: T
authors.lastname: Daly
authors.forename: X Sylvia
authors.initials: XS
authors.lastname: Chen
authors.forename: David
authors.initials: D
authors.lastname: Penny
mesh_terms: D000818:Animals; D019143:Evolution, Molecular; D053263:Gene Regulatory Networks; D006801:Humans; D012313:RNA / Q000235:genetics*; D034622:RNA Interference; D012329:RNA, Bacterial / Q000235:genetics; D012331:RNA, Fungal / Q000235:genetics; D018749:RNA, Plant / Q000235:genetics; D012335:RNA, Ribosomal / Q000235:genetics*; D012343:RNA, Transfer / Q000235:genetics*; D022661:RNA, Untranslated / Q000235:genetics*; D012261:Ribonucleoproteins / Q000235:genetics; D013045:Species Specificity; D013997:Time Factors
chemical_list: D012329:RNA, Bacterial; D012331:RNA, Fungal; D018749:RNA, Plant; D012335:RNA, Ribosomal; D022661:RNA, Untranslated; D012261:Ribonucleoproteins; D012313:RNA; D012343:RNA, Transfer