Electrophoretic patterns of deadenylylated chorion and globin mRNAs

Treatment of silkmoth chorion mRNAs with calf thymus RNase H (EC 3.1.4.34; RNA-DNA-hybrid ribonucleotidohydrolase) in the presence of oligo(dT) specifically and effectively removes the 3'-terminal poly(A) sequences. Excision of non-poly(A) fragments cannot be detected. Under these conditions, RNase H leads to increased electrophoretic homogeneity of rabbit globin mRNA, presumably as a result of removal of poly(A) sequences that are inherently variable in length. Treatment with RNase H converts the three diffuse zones of messages for the several chorion proteins into multiple sharp bands.