Figure 6.

Expression of the UHHU genes. 10 μg total cell RNA from cells transfected with the UHH₁₅₆ gene lanes 1, 4, and 5) or the UHHU₁₁₇ gene (lanes 2, 3, and 6) were analyzed by S1 nuclease mapping. The UHU₁₅₆ gene labeled at the 3′ end of the Narl site as a probe in lanes 1 and 2. The UHHU₁₁₇ or UHHU₁₅₆ gene labeled at the Narl site was used as a probe in lanes 3 and 4 respectively. The 5′ ends of the genes were analyzed in lanes 5 and 6 using the U₅H gene labeled at the 5′ end of the NarI site as a probe as in Figure 3B. Lane M is marker pUC18 digested with HpaII. The protected fragments are: H2a_H-protection of the endogenous hamster H2a mRNAs; H2a_M–protection by transcripts extending to the 3′ end of the mouse H2a–614 gene; T–protection by all transcripts from the UHHU genes to the point of divergence between the UHHU gene and the UHU₁₅₆ gene; U1–protection by transcripts initiating at the U1 start site. Band P is unprotected probe DNA. A schematic of the S1 nuclease assays is shown below the figure.