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Dr. Mari Salmi Today: Telomeres, Cancer and Aging
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CB 19.14 Multiple mutations are required for a single cell to become cancerous.
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Causes of mutations: Replication errors –Exacerbated by poor DNA repair Other biological agents –Viruses –Transposons Environmental factors –Ultraviolet light –Mutagenic chemicals smoking, industrial waste, natural toxins
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DNA replication is necessary but dangerous
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Telomeres are non-gene DNA at the ends of DNA strands.
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Telomeres are shortened during DNA replication.
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Telomeres are non-gene DNA at the ends of DNA strands. Telomeres are shortened during DNA replication, and also by DNA damage.
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Telomeres are non-gene DNA at the ends of DNA strands. Short telomeres will cause cells to stop replicating or cell death. The critical size is unknown.
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Telomerase is a ribo- protein that can extend the DNA strand CB 16.18
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Human Life Cycle high levels of telomerase very little telomerase
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Why not produce telomerase all of the time? high levels of telomerase very little telomerase
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Telomeres are non-gene DNA at the ends of DNA strands. Telomeres are shortened during DNA replication, and by DNA damage. Short telomeres will cause cell senescence or cell death. Telomere size is a measure of mutations.
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Do telomere dynamics link lifestyle and lifespan? Pat Monaghan and Mark F. Haussmann TRENDS in Ecology and Evolution Vol 21 pg 47
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Telomere length varies in different parts of adults: telomeres - mitosis stomach & blood cells....short- often muscle & brain……….long- rare gametes……long liver & kidney……..short- rare
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Telomeres are non-gene DNA at the ends of DNA strands. Telomeres are more sensitive DNA damage, and may act as a sensor for overall DNA damage level in a cell.
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Does telomere length indicate longevity?
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Zebra finch Telomere length in red blood cells of different birds Fig. 1 TRENDS in Ecology and Evolution Vol 21 pg 47 Age (years)
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common tern Telomere length in red blood cells of different birds Fig. 1 TRENDS in Ecology and Evolution Vol 21 pg 47 Age (years)
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albatross TRENDS in Ecology and Evolution Vol 21 pg 47 Telomere length in red blood cells of different birds
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Leach’s storm petrel Telomere length in red blood cells of different birds Fig. 1 TRENDS in Ecology and Evolution Vol 21 pg 47
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Zebra finch Leach’s storm petrel common tern albatross Telomere length in red blood cells of different birds, different species have different patterns of telomere length and age Fig. 1 TRENDS in Ecology and Evolution Vol 21 pg 47
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Fig. 2 TRENDS in Ecology and Evolution Vol 21 pg 47 Telomere length in white blood cells of different aged people. Telomere length generally declines, but there is wide variability
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THE LANCET Vol 361 pg 393 Telomere length and mortality in people over 60 years old upper 50% of telomere length lower 50% of telomere length proportion surviving % years after initial assessment
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Telomere length may indicate biological age. Early stress may cause premature telomere degradation.
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Telomere length is an issue in cloning. Dolly started out life with short Telomeres
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