Globin mRNA contains a sequence complementary to double-stranded region of nuclear pre-mRNA

Melted ds RNA isolated from rabbit bone marrow pre-mRNA was hybridized with excess of globin mRNA which was prepared from rabbit reticulocytes. 7-9% of ds sequences became RNAase-stable and about 30% of the sequences could be bound to poly(U)-Sepharose through poly (A) of mRNA. The size of RNAase-stable hybrid is about 30 nucleotides, that is one fourth of the length of one strand of the ds RNA.