tRNA pool analysis of S. cerevisiae using tRNA-HySeq

For a typical RNA polymerase (pol) II transcribed budding yeast gene, the 5' -end is characterized by a nucleosome-free region (NFR) immediate upstream of the transcription start site (TSS), flanked by two well-positioned nucleosomes (-1 and +1) containing H2A.Z. A similar arrangement of nucleosomes containing H2A.Z is found on the genes transcribed by pol III, which reside in the NFR actively maintained by the chromatin remodeling complexes. We did genome-wide MNase-seq and ChIP-seq experiments to study the nucleosome arrangement near pol III transcribed genes. We also measured the levels of different tRNAs in the tRNA pool of the wild type and Spt16 mutant (*spt16-197*) cells using tRNA-HySeq method. Although, it is difficult to measure the primary transcripts of tRNA due to their quick processing and the sequence degeneracy of the tRNA isogenes; a comparison of the wild type and Spt16 mutant showed both increase or decrease of tRNA transcripts. The result suggest that Spt16 may not be necessary for the transcription per se of tRNA genes. Overall design: tRNAs isolated from log phase yeast cells were hydrolyzed, followed by adapter ligation and sequencing. Single end RNA sequencing on Illumina Next-seq 500.