Gerontogenic
As Gerontogene so-called "longevity genes" are designated by a loss-of-function mutation , the life span can be extended by 40 to 100%. They have been discovered and proven so far in Caenorhabditis elegans ( roundworm ) and Drosophila melanogaster ( fruit fly ). It is postulated that these genes also play a role in humans.
In humans, it is assumed that 10 to 33% of the life span is inherited. Much more important are the lifestyle ( diet , sport , alcohol and tobacco consumption, etc.) and the environmental factors that affect him.
Gerontogens from Caenorhabditis elegans
age-1
The age-1 gene encodes a gene product that is responsible for the production of the enzyme phosphoinositide-3-kinase . This enzyme plays an important role in various signal transductions (transmission of signals that reach the cell from outside).
daf-2
The daf-2 gene codes for the insulin / IGF-1 receptor .
age-1 , daf-2 and the regulation of longevity
Loss of function of daf-2 and age-1 result in increased activity of the transcription factor DAF-16. This affects the activity of genes that control metabolic rate , stress response (including detoxification of reactive oxygen compounds ), and antimicrobial actions , among other things . In the wild type (non- mutated genes) daf-2 and age-1 inhibit the expression of daf-16 . The activity of the mutants is reduced by the loss-of-function mutation of daf-2 and age-1 . This means that daf-16 is no longer inhibited and can exercise its function as a transcription factor. Proteins (mostly enzymes) are now produced which have the positive effects mentioned above.
clk-1
Clock genes regulate physiological processes, development and behavior during the life cycle. Clk-1 is responsible for the biosynthesis of coenzyme Q9 in the mitochondria and thus for the electron transport chain. Mutations in this gene presumably extend the life span by reducing the formation of reactive oxygen compounds in the mitochondria.
Longevity genes in Drosophila melanogaster
Indy
Indy means I am not dead yet ( dt. , I'm not dead yet ') and can extend the life span of fruit flies by up to 100%. The gene codes for a dicarboxylate transporter involved in metabolism. The mutation probably affects the metabolic rate.
Methuselah gene ( mth )
A loss-of-function mutation in this gene probably extends the life span by around 30%. It codes for a G-protein coupled transmembrane receptor-like molecule. Mutants show an increased resistance to heat and oxidative stress.
See also
swell
- L. Guarente and Cynthia Kenyon : Genetic pathways that regulate aging in model organisms. In: Nature 408, 2000, pp. 255-262.
- S. Nemoto and T. Finkel: Aging and the Mystery at Arles. In: Nature 429, 2004, pp. 149-152.
- H. Niedermüller and G. Hofecker: Lifespan: Genetic determination and life-lengthening strategies. In: Molecular medical principles of age-specific diseases. D. Ganten and K. Ruckpaul (eds.), Springer-Verlag, Heidelberg, 2004, pp. 8-66.