A regulatory role for viral RNA in eukaryotes

• Published in: Journal of theoretical biology Vol. 49; no. 2; pp. 461 - 492
• Main Author: Reanney, D.C.
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 01.02.1975
• Subjects: Bacillus; Bacteriophages; Biological Evolution; Cell Nucleus; DNA - metabolism; Enzyme Repression; Genes; Genes, Regulator; Lipoproteins; Membranes; Plant Viruses; RNA Viruses; RNA, Viral - metabolism; Transcription, Genetic; Vegetables
• ISSN: 0022-5193; 1095-8541
• DOI: 10.1016/0022-5193(75)90186-1

Reasons for believing that regulatory RNA plays a role in aspects of embryogenesis are summarized. The upper limit to the number of bases one protein can recognize effectively is about 25; by contrast, a specific recognition of DNA by RNA is possible with sequences as short as 50–200. Experimental evidence is marshalled to support the contention that sequences of this size are important in gene activation. It is suggested that elements of the genomes of certain RNA virions constitute regulatory signals which have ceased to carry out their original functions of gene activation during normal ontogeny. Specifically it is postulated that the viroid RNA of potato tuber spindle virus is a regulatory RNA of cellular origin which has escaped from the controls to which its production is subjected in non-mutated systems. It is shown that if such RNA signals were to be encapsulated in lipoprotein membranes carrying simple labels then the resulting particles could effectively perform the tasks of cell-to-cell signalling which must operate during embryogenesis if data transcribed from the DNA of one cell is to influence the developmental fate of physically remote cells. The view is therefore put forward that pathogenic members of budding virus genera, in particular the leukovirus and the arenavirus groups, represent aberrant examples of entities which fulfil an essential role in ontogeny. It is shown that this assumption rationalizes a substantial amount of data in tumour virology and embryology. This concept enables metazoan organisms to be re-examined from a standpoint that makes their origin and development more readily intelligible.