Science and techno world topic: Genetics
|Father and child: Long caps in the genome|
Late paternity may extend the life of the young - scientists come to this conclusion after comparing genetic strands. Old fathers pass on to their children, therefore protective caps in the genes.
Washington - men who are late father bequeath to their children and grandchildren long "caps" at the ends of chromosomes. A shortening of telomeres is usually associated with aging processes in combination. It is possible that the long caps in the offspring of older fathers had a positive impact on their health or even their survival. Researchers come to this conjecture in the scientific journal "PNAS" according to the analysis of genome sequences, called telomeres.
Telomeres are repetitive DNA sequences at the ends of chromosomes. In almost all cells, telomeres shorten with each cell division a little. The older a person, the shorter the telomeres are therefore usually its chromosomes. The shortening of these protective caps too strong, there is no cell division takes longer. In an earlier study, researchers found that older people with above-average short telomeres and a shorter life expectancy.
When the sperm cells, the situation is different: in their chromosomes, the telomeres with increasing age of the men getting longer. Presumably this is due to a particularly high activity in the testis of the telomerase enzyme - this is responsible for the construction of the telomeres.
The researchers led by Dan Eisenberg of Northwestern University (Evanston / U.S. state of Illinois) is now being investigated in a large, mixed-age group in the Philippines, whether the telomere length of the Father, the telomere length in children and grandchildren affected.
To determine the length of telomeres in their body cells, the researchers extracted the blood test subjects. It was found that telomere length in the children actually had to do with the age of the father at birth. Moreover, such children had never even longer telomeres, whose paternal grandfathers were late become a father. That is, the age of grandfathers - and thus the greater telomere length - had an impact not only on the children, but also on the grandchildren. Over two generations, the effect even added.
Each year, the fathers had later received a child who grew the telomeres, the researchers report.
Whether the extended caps actually affect favorably the health and life expectancy of the children and grandchildren, should be further investigated. The scientists speculate, however, that the extension of telomeres in societies with low mortality and more late reproduction increases the life expectancy of offspring.