Dr. Mari Salmi Today: Telomeres, Cancer and Aging

CB Multiple mutations are required for a single cell to become cancerous.

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

DNA replication is necessary but dangerous

Telomeres are non-gene DNA at the ends of DNA strands.

Telomeres are shortened during DNA replication.

Telomeres are non-gene DNA at the ends of DNA strands. Telomeres are shortened during DNA replication, and also by DNA damage.

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.

Telomerase is a ribo- protein that can extend the DNA strand CB 16.18

Human Life Cycle high levels of telomerase very little telomerase

Why not produce telomerase all of the time? high levels of telomerase very little telomerase

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.

Do telomere dynamics link lifestyle and lifespan? Pat Monaghan and Mark F. Haussmann TRENDS in Ecology and Evolution Vol 21 pg 47

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

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.

Does telomere length indicate longevity?

Zebra finch Telomere length in red blood cells of different birds Fig. 1 TRENDS in Ecology and Evolution Vol 21 pg 47 Age (years)

common tern Telomere length in red blood cells of different birds Fig. 1 TRENDS in Ecology and Evolution Vol 21 pg 47 Age (years)

albatross TRENDS in Ecology and Evolution Vol 21 pg 47 Telomere length in red blood cells of different birds

Leach’s storm petrel Telomere length in red blood cells of different birds Fig. 1 TRENDS in Ecology and Evolution Vol 21 pg 47

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

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

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

Telomere length may indicate biological age. Early stress may cause premature telomere degradation.

Telomere length is an issue in cloning. Dolly started out life with short Telomeres