Patent ID: 7618774

Claim:
A method of identifying a gene that alters the lifespan of an organism, said method comprising: providing a control cell culture and one or more test cultures each comprising mother and daughter cells possessing two chimeric genes encoding a protein required for replication, one gene under control of an inducible promoter responsive to growth medium conditions and the other gene under control of a promoter operable in mother cells but not daughter cells; wherein one or more test cell cultures but not the control cell culture comprise mother yeast cells that possess a genotype modification of either a non-essential gene or an essential gene, in which case the genotype modification is non-lethal; culturing the control cell cultures and one or more test cell cultures under conditions whereby mother yeast cells can replicate and daughter yeast cells cannot; and determining whether the mother yeast cells in the one or more test cell cultures exhibit a change in replicative lifespan when compared to the mother yeast cells in the control cell culture, wherein an increase in the replicative lifespan for mother yeast cells of a test cell culture indicates that the genotype modification enhances the replicative lifespan of an organism possessing the genotype modification and a decrease in the replicative lifespan for mother yeast cells of a test cell culture indicates that the genotype modification decreases the replicative lifespan of an organism possessing the genotype modification; wherein the yeast strain is a homozygous diploid host strain of yeast carrying two identical copies of each of the two chimeric genes but having a mutation in one copy of the non-essential gene.