Poster abstracts
Poster number 158 submitted by Mark Wilson
Global gene expression analysis in circularized chromosome strains of Saccharomyces cerevisiae
Mark T. Wilson (Department of Biology and Chemistry, Morehead State University), Blake Hoover (Department of Biology and Chemistry, Morehead State University), Chisom Iloegbunam (Department of Biology and Chemistry, Morehead State University), Austin Lytle (Department of Biology and Chemistry, Morehead State University), Caleb Clark (Department of Biology and Chemistry, Morehead State University), Melissa A. Mefford (Department of Biology and Chemistry, Morehead State University)
Abstract:
Telomeres are repeated sequences at the ends of linear chromosomes that act as biological clocks, requiring the ribonucleoprotein telomerase enzyme to maintaining telomere length. Loss of telomerase activity results in short telomeres that trigger senescence and aging, while aberrant up-regulation of telomerase activity is observed in >85% of human cancers. Understanding the delicate balance between telomere length and telomerase activity has important implications for both human aging and cancer. An important model system for studying telomere function is the genetically modifiable yeast, Saccharomyces cerevisiae. Our laboratory has genetically engineered strains of yeast where individual linear chromosomes (Ch. II, IV, VIII, and XV) have been circularized to investigate the role of telomeres and chromosome architecture. Examination of doubling times in these strains shows no significant difference in mitotic fitness in circularized strains relative to wildtype. However, cell size measurements showed significant increases in Ch. VIII circular strains relative to wildtype. Previous studies have identified several genes on Ch. VIII that may be involved in cell size homeostasis. Currently, we are performing whole genome sequencing of each circular chromosome strain to confirm sequence integration and circularization, and ensure no other alterations were introduced. Further, we are performing genome-wide RNA-sequencing experiments to identify the gene expression changes in the circular strains, and are particularly interested in changes that may affect cell size in Ch. VIII. The evaluation of telomere-free circularized chromosomes provides a unique model to identify important regulatory roles for telomere repeats in gene regulation and cellular function.
Keywords: telomere, yeast, chromosome