lecture 18 Flashcards
How can genetic variation influence lifespan?
Genetic variaton in “longevity” genes may influence lifespan
What is an SNP (single nucleotide polymophisms)
- A difference in a single DNA building
block (nucleotide - Most frequent source for polymorphic
changes - Not the only source of genetic
variation but represents major source
that distinguishes one individual from
another
How many SNP’s for every nucleotide?
1 every 300
What increase is aging associated with?
Aging is associated with an increase in inflammatory cytokines that contribute to various age-related disorders
* Alzheimer’s, cardiovascular disease, arthritis
What is Interleukin-6 (IL-6)? and what does it indicate/correlate?
an inflammatory cytokine
* Plasma levels positively correlated with greater mortality
What is SNP in the promotor of IL-6 associated with?
associated with an increase in IL-6 & an increased mortality rate
* Promoter = region of DNA that initiates transcription of a particular gene
What is a polymorphism?
a DNA sequence variation that is common in
the population
What does the mitochondria contain?
Contains genes
e.g. components of the electron transport chain
How much more often does mitochondrial genome damage occur and why does the damage occur?
- Damage to the mitochondrial genome occurs 10x more frequently than nuclear genome
- Damage due to generation of reactive oxygen species (ROS)
- Highly reactive chemical species containing oxygen
- E.g. peroxides, superoxide, hydroxyl radical, singlet oxygen
What is DNA polymerase gamma
Replicates & proofreads/repairs
mitochondrial DNA
What happens with age regarding errors?
Errors in replication become more frequent with age
What accelerates aging?
Accumulating mutations in mitochondrial DNA accelerates aging
With aging, What does DNA polymerase gamma do?
With aging, DNA polymerase gamma corrects errors less effectively
What happened when Mice genetically engineered to carry mutations in mtDNA polymerase gamma which meant that mtDNA replication error-prone & proofreading activity lost.?
Mice show accelerated signs of aging evident by 25 weeks (young adult stage), weight loss, hair loss, curvature of spine i.e. reduced lifespan
* Causative link between mtDNA mutations & aging phenotype
Healthy aging can be influenced by _____?
lifestyle choices
