Clustered tRNA genes in Schizosaccharomyces pombe centromeric

The centromere-associated B' and B DNA sequence repeats of Schizosaccharomyces pombe chromosomes I and II have been found to contain clusters of tRNA genes. The centromere II region (cen2) includes at least 22 tRNA genes distributed among five copies of the B sequence repeat con- taining genes specifying tRNAIIe, tRNAAIa, and tRNAval. In- dividual B repeats are variously associated with other tRNA genes, including those specifying tRNALYS, tRNA , and tRNAGIu. The centromere I region (cenl) contains at least six tRNA genes in two copies of the B' repeated element, including genes specifying tRNAIIe, tRNAAIa, and tRNA3Iu. Multiple tandemly arranged clusters of tRNA genes are presumably conserved due to restricted recombination frequencies in the , ~ ~ ~ ~ ~ ~ ~ ~ I _. -O.W-< K L B J K L B J K L B B L K B