dsRNA
Double-stranded RNA (dsRNA) is often formed in the nuclei of mammalian cells, but in this compartment it does not induce the effects characteristic of cytoplasmic dsRNA.
Nuclear dsRNA could be a target for the ADAR class of enzymes, which deaminate adenosines to inosines. Further, there are a number of distinct fates of such edited RNA, including nuclear retention and perhaps also gene silencing.
References
Chapman EJ, Carrington JC. Specialization and evolution of endogenous small RNA pathways. Nat Rev Genet. 2007 Nov;8(11):884-96. PMID: #17943195#
DeCerbo J, Carmichael GG. Retention and repression: fates of hyperedited RNAs in the nucleus. Curr Opin Cell Biol. 2005 Jun;17(3):302-8. PMID: #15901501#