Mutation in the silencing gene SIR4 can delay aging in S. cerevisiae
Gene mutations that affect silencing at HM loci, telomeres and other regions of the chromosome have been shown to relate to stress resistance and aging in Saccharomyces cerevisiae. S. cerevisiae is a species of yeast in which goes through asymmetrical cellular division. Its lifespan is measured by the number of cellular divisions the mother cell is able to complete before death. In the research study by Kennedy et al, the researchers focused on yeast cells and how stress tolerance can extend lifespan through silencing genes, like SIR4. SIR4, a silencing gene, works with other SIR genes to form a SIR complex which regulates expression at regions on the chromosome. Some of the …show more content…
This suggested that there were genes present in segregants of the cross that caused an increase in resistance to stress and lifespan. A segregant of the cross,14c, was tested for genes that could extend lifespan through mutations while resistant to starvation.The segregant was mutagenized, grown and starved for 8 days. This process made it express certain genes in response to the stress condition. It was then transferred to a rich plate to grow. 39 mutants were created from this process and these mutants exhibited various phenotypes, a strain uth2-42 was isolated from the …show more content…
This meant that the SIR complex, and not just SIR4 is involved in lifespan extension. Due to the possibility that sir complexes could be relocated to other parts of the chromosome, the researchers studied the effect sir4-42 mutation had on telomeres and other chromosomal regions. Loss of function mutations in any of the components of the SIR complex are expected to stop silencing at the telomeres and cause shorter telomeres. However, the researchers concluded that lengthened life span was not related to telomere length and silencing since the telomere length of sir4-42 mutants and SIR4 mutants were similar. Then, to understand if the SIR complex could still extend life span at other regions of the chromosome the researchers redirected the SIR complex from both the HM loci and telomeres. They noticed that the strain expressing the SIR complex at other chromosomal regions expressed an extension in lifespan by about
Gene mutations that affect silencing at HM loci, telomeres and other regions of the chromosome have been shown to relate to stress resistance and aging in Saccharomyces cerevisiae. S. cerevisiae is a species of yeast in which goes through asymmetrical cellular division. Its lifespan is measured by the number of cellular divisions the mother cell is able to complete before death. In the research study by Kennedy et al, the researchers focused on yeast cells and how stress tolerance can extend lifespan through silencing genes, like SIR4. SIR4, a silencing gene, works with other SIR genes to form a SIR complex which regulates expression at regions on the chromosome. Some of the …show more content…
This suggested that there were genes present in segregants of the cross that caused an increase in resistance to stress and lifespan. A segregant of the cross,14c, was tested for genes that could extend lifespan through mutations while resistant to starvation.The segregant was mutagenized, grown and starved for 8 days. This process made it express certain genes in response to the stress condition. It was then transferred to a rich plate to grow. 39 mutants were created from this process and these mutants exhibited various phenotypes, a strain uth2-42 was isolated from the …show more content…
This meant that the SIR complex, and not just SIR4 is involved in lifespan extension. Due to the possibility that sir complexes could be relocated to other parts of the chromosome, the researchers studied the effect sir4-42 mutation had on telomeres and other chromosomal regions. Loss of function mutations in any of the components of the SIR complex are expected to stop silencing at the telomeres and cause shorter telomeres. However, the researchers concluded that lengthened life span was not related to telomere length and silencing since the telomere length of sir4-42 mutants and SIR4 mutants were similar. Then, to understand if the SIR complex could still extend life span at other regions of the chromosome the researchers redirected the SIR complex from both the HM loci and telomeres. They noticed that the strain expressing the SIR complex at other chromosomal regions expressed an extension in lifespan by about