Can RNA anneal to single stranded DNA?

[maxjohn]

I'm not sure if my terminology is correct, but could you have a DNA-RNA heterodimer? I'm thinking particularly about whether an mRNA transcript that was not translated could act like a transcription factor.

[JackBean]

sure it can anneal. You basically answered by yourself, because during transcription there is the duplex, the same for replication (RNA primer) or RNAi process. Also that's principle of some DNA chips