Yeast As a Model Organism To Assay the Functional Relevance of nsSNPS in Mitochondrial Disorders

Abstract

This thesis explores two yeast experiments. The first experiment, which was performed during the summers of 2011 and 2012, involved developing several yeast strains (including yeast strains with human wild-type orfeomes and yeast strains with human mutant orfeomes) and analyzing their growth rates with a flow cytometry growth competition assay. In this experiment, we hypothesized that 1) the yeast wild-type strains would grow better than the yeast deletion strains because the yeast deletion strain is lacking a growth gene and 2) the yeast strains with human wild-type orfeomes would grow better than the yeast deletion strains. The results of this experiment supported both hypotheses and validate our approach as a successful way to determine the relevance of certain nsSNPs in humans. The second yeast experiment, performed by scientist Sze Chern Lim and colleagues, involved identifying a homozygous mutation in two cousins with OXPHOS deficiency by using various sequencing techniques. After the homozygous mutation was identified, a mutant LYRM4 gene was able to partially complement for an ISD11 deletion in yeast. For this experiment, the scientists hypothesized that L-cysteine desulferase activity of NFS1 would be minimally present when co-expressed with a mutant ISD11 protein; the results of their in vitro experiments supported this hypothesis.