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Implications of Genetic Damage

 

Mutagenic damage can produce significant consequences not only in the individual in which it is detected, but also in the whole population. Somatic cell effects which impact on individual reproductive effectiveness can produce indirect multigenerational genetic effects through selection for adaptation to the contaminant stressor. Germ cell effects can cause direct impacts through mutations passed on to the next generation that may ultimately become fixed in the gene pool of the population in future generations.

 

Somatic Cells

  • Significantly higher frequency of cell death
    • Level 2 genetic damage can trigger premature cell death. This higher turnover in cells will place increased energy demands on the animal or plant. During periods of food scarcity (i.e. in winter), this could result in an increase in juvenile mortality.
  • Disruption, alteration or loss of cell function
    • impairment of immune function in damaged white blood cells
      • greater lifetime susceptibility to effects of endemic pathogens
      • causes differential fitness within the population
    • Possible impairment of oxygen transport by red blood cells
  • Greater risk of Cancer
    • The risk is especially high during the rapid growth of the juvenile stage.
    • Symptoms of the disease may occur 4 to 6 months after exposure.
  • Adaptive selection in response to effects on fitness.
    • Reduction of useful genotype variation.
      • Reduced ability of the population to genetically respond to new selection pressures (i.e. effects of global warming).

 

Germ Cells

  • Increase in the background mutation rate (possibly compounded over generations).
    • Increased genetic variation because of greater mutation rate
    • Decreased useful genetic variability (similar to inbreeding) prevents population adaptation to novel environmental stressors.
    • Greater susceptibility to cancer and carcinogens.
    • Decreased effectiveness of the immune system;
    • Decrease in fertility;
      • Greater frequency of defective sperm
      • Higher frequency of post-zygotic and embryonic mortality
  • Increase in Recombinational Load
    • Break-up of favourable gene combinations that are normally tightly linked.
    • Alteration of optimum pre-adapted genotype frequencies.
      • reduced potential for pre-adaptation to environmental extremes

 



Types of Mutation
Consequences of Mutation
Our DNA Damage Detection Method

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Updated by Michael Easton 2009.