Figure 3.

In vivo expression of SNR6-SPIN alleles. Primer extension analysis of total cellular RNA from strains containing SNR6–SPIN alleles (or a wild-type control) on a TRP1-marked centromere plasmid and wild-type SNR6 on a URA3-marked centromere plasmid. (A) Primer extension was done using ³²P-labeled oligonucleotide 6D (complementary to the 3′ end of U6 RNA) and the resulting cDNA products were run on a denaturing 6% polyacrylamide gel. Lanes 1–4 (U, G, C, A) represent a sequencing ladder generated from the RNA used in lane 6. Lanes 5–7 show cDNAs from strains with the indicated alleles on the TRP1 plasmid. The positions of pre-U6 and U6 cDNAs are indicated on the right. (B) Primer extension was done using ³²P-labeled oligonucleotide SPIN3 (complementary to positions 22 to 35 of the S.pombe U6 intron) and the resulting cDNA products were run on a denaturing 6% polyacrylamide gel. Lanes 1–4 (U, G, C, A) represent a sequencing ladder generated from the RNA used in lane 7. Lanes 5–10 show cDNAs from duplicate RNA preparations from strains containing the indicated alleles on the TRP1 centromere plasmid. The position of pre-U6 cDNA is indicated on the right.