Multiple PRV-1 mRNA species are generated by alternative polyadenylation.

Northern blot analysis of granulocyte RNA from 3 patients with polycythemia vera. PRV-1 cDNAs of various lengths were amplified by 3′ RACE and sequenced. The blots were hybridized with 2 different cDNA probes as indicated: probe 1 is derived from the coding region of the cDNA, whereas probe 2 is derived from the 3′ untranslated region of a RACE product. The positions of the 28S and 18S ribosomal RNAs are indicated.