(a) Northern blotting analysis for determining the expression of MDV-1 miRNAs. Twenty micrograms of total RNA from MSB-1 cells, the MDV-negative lymphoid cell line AVOL-1, MDV-1-infected CEF, uninfected CEF, or MD lymphoma tissues was separated in a 15% denaturing polyacrylamide gel, blotted, and probed with end-labeled antisense oligonucleotides to the indicated miRNAs. Size markers to indicate the positions of the pre-miRNA and the mature miRNA are shown. The cellular U6 snRNA served as the loading control, and a representative blot of this set is shown. (b) Analysis of tissue-specific expression of Gallus gallus (gga-) miRNAs identified in the MSB-1 library. Total RNAs (20 μg) extracted from different tissues of chickens were separated in polyacrylamide gels and probed with end-labeled antisense oligonucleotides specific for the individual miRNAs indicated. The cellular U6 snRNA served as the loading control.