Researchers are discovering different types of viroids and viroid-like agents

A team of researchers from the National Library of Medicine (NLM) and collaborating academic research organizations have developed a computational pipeline to identify and better understand viroids and viral-encoded circular RNAs (cccRNAs, which also called circular RNAs). This is a type of single-stranded RNA, unlike linear RNA, which forms a closed, continuous loop. The findings were published in the journal A cell.

Viroids are circular RNAs of only 250 to 400 nucleotides, and are the smallest and simplest of known viruses. It is believed that they cause infection only in plants. The different types of RNA such as viroid and viroid are not well understood, which has led researchers to investigate more about these viruses and their potential abundance in other areas.

By searching a collection of 5,131 metatranscriptomes and 1,344 plant transcriptomes for viroid-like cccRNAs, the researchers discovered 11,378 cccRNAs spanning 4,409 species. This finding was a fivefold increase compared to previously known substances such as viroids.

Within this diverse collection, the researchers discovered that this unique group of microbes is not limited to a few plants as previously thought, but is common and has and all types of sites and multiple sites, compared to the most well-known RNA viruses. In addition, close human relatives of the Hepatitis Delta (Hepatitis D) virus were discovered, which sheds light on the origins of this important human virus, as well as rare strains of the virus. – be careful.

“This work opens new avenues for researchers around the world,” said Eugene V. Koonin, Ph.D., study co-author and senior investigator in the Department of Computational Biology of the Intramural Research Program. of NLM. He added: “We are currently conducting further investigations.