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snR70 Identified by Comparative Genomics

We also used the program to scan genome sequence from other eukaryotes including human, C. elegans, and Schizosaccharomyces pombe (manuscript in preparation). We identified S. cerevisiae snR70 by comparison with our results from the S. pombe snoRNA search. One tandem group of three S. pombe snoRNAs appears to be syntenic with three tandem S. cerevisiae snoRNAs (snR41, snR70, snR51). The 5' most snoRNAs in each array both target SSU-Gm1123, the middle snoRNAs both target SSU-Cm1637, and the 3' most snoRNAs both target LSU-Um2726. Our snoRNA search program had not identified snR70 as one of the top snoRNA candidates due to what appears to be a single nucleotide bulge within the snoRNA/rRNA paired region. Given the strong prediction for the middle S. pombe snoRNA, we then re-examined the sequence between S. cerevisiae snR41 and snR51, and found snR70. As described above, we verified expression of snR70, and observed loss of the weak stop at Cm1637 for the disruption mutant. Considering the evolutionary distance between these organisms, genuine synteny would imply that these snoRNAs are at least one billion years old.


next up previous contents
Next: Discussion Up: Results Previous: Expression and 5' ends
Todd M. Lowe
2000-03-31