Interstrand duplexes in hnRNA: the occurrence of retrotransposon antisense sequences

We have previously identified a class of non-polyadenylated hnRNA molecules (CLASS IA-) which hydrogen bond to polyadenylated hnRNA molecules. Characterization of clones from a Drosophila Class IA- cDNA library reveals that 18S rRNA and transcripts derived from intermediate repeat DNA constitute the bulk of such molecules. The most abundant non-ribosomal clone in the library derives from the antisense strand of the Copia retrotransposon and occurs in Drosophila Kc cell Class IA- hnRNA as non-polyadenylated transcripts of 10 and 15 kb.