RNAd

RNAd is an acronym without a single, universally accepted definition in the life sciences. In published literature and across databases, it has been used in different ways to refer to RNA-related activities that interact with DNA, but its meaning is highly context dependent. Because RNAd is not standardized, readers should consult the source’s glossary or the authors’ definitions to determine what is meant in a given text.

Common interpretations of RNAd include:

- RNA-dependent DNA synthesis, a process in which an RNA molecule serves as a template for DNA synthesis. This is classically associated with reverse transcription performed by reverse transcriptase enzymes in retroviruses and retroelements, though some authors prefer the explicit term “reverse transcription.”

- RNA-directed DNA processes in epigenetics or genome maintenance, such as pathways where RNA cues influence DNA methylation or DNA modification states. In plants, for example, pathways like RNA-directed DNA methylation are well established, but the standard shorthand for this mechanism is RdDM rather than RNAd.

- A project- or database-specific acronym for RNA-binding or RNA-associated domains or protein families, used only within particular research groups or resources.

Usage guidance:

Because RNAd lacks standardization, it is important to determine its precise meaning from the source material. When introducing the term in a document, scholars are advised to spell out the full term first and provide a clear definition, then use the acronym consistently thereafter. Where possible, prefer widely recognized terms (e.g., reverse transcription, RdDM) to reduce ambiguity.

See also: reverse transcription, RNA-dependent RNA polymerase, RNA-directed DNA methylation, RNA editing.