RESUMEN
Among all RNA viruses, coronavirus RNA transcription is the most complex and involves a process termed "discontinuous transcription" that results in the production of a set of 3'-nested, co-terminal genomic and subgenomic RNAs during infection. While the expression of the classic canonical set of subgenomic RNAs depends on the recognition of a 6- to 7-nt transcription regulatory core sequence (TRS), here, we use deep sequence and metagenomics analysis strategies and show that the coronavirus transcriptome is even more vast and more complex than previously appreciated and involves the production of leader-containing transcripts that have canonical and noncanonical leader-body junctions. Moreover, by ribosome protection and proteomics analyses, we show that both positive- and negative-sense transcripts are translationally active. The data support the hypothesis that the coronavirus proteome is much vaster than previously noted in the literature.
RESUMEN
The complete genome sequences of Mandrillus leucophaeus and Papio ursinus cytomegaloviruses were determined. An isolate from a drill monkey, OCOM6-2, and an isolate from a chacma baboon, OCOM4-52, were subjected to pyrosequencing and assembled. Comparative alignment of published primate cytomegaloviruses (CMVs) showed variable sequence conservation between species.
