Prolonging life: remove the paternal genes!
Life is longer without DadAlexandra Borisova, Newspaper.
RuLong life to mammals, perhaps, is given by female genes.
Mice born from "two mothers" lived longer without experiencing the life-shortening effects of male genes.
Japanese scientists have found that female mice artificially bred using only female genetic material turned out to be long-lived. "Daughters of two mothers" have led scientists to the idea that genes from sperm can have a detrimental effect on life expectancy. The study is published in the latest issue of Human Reproduction (Manabu Kawahara and Tomohiro Kono, Longevity in mice without a father).
Mice carrying only female genetic material lived 186 days longer compared to the control sample. Their life expectancy was 600-700 days, that is, the removal of male genes increased it by almost a third.
Professor Tomohiro Kono and his colleagues from the Tokyo University of Agriculture believe that the difference in life expectancy may be due to the gene of chromosome 9, which is associated with postpartum growth.
"The fact that women in almost all countries of the world live longer than men is not news. The same sex differences in life expectancy are observed in a number of mammals. However, the causes of this phenomenon are still unknown. In addition, there is a question about which set of genes determines the life span of mammals – whether it is transmitted from one of the parents or from both," said Professor Kono.
To answer all these questions, scientists have specially created a control group of mice bred without the participation of sperm. They isolated oocytes (immature eggs) from mice one day old. The genetic material of these cells has been "reprogrammed" so that they work as sperm genes. This material was injected into unfertilized eggs of adult mice with the nucleus removed. The modified oocytes developed into embryos, which were then transplanted into the body of a surrogate mouse mother. The mice that were born were "daughters of two mothers", there was no male genetic material in them.
At the second stage, a control group of mice was created. Genetically, they were identical to the modified ones, but they were born in the usual way from female and male individuals. Thus, between October 2005 and March 2006, 13 modified and 13 "control" mice were born. "Female" mice lived an average of 841.5 days, and ordinary mice lived 655.5 days, 186 days less.
Among ordinary mice, the record of life expectancy was 996 days (12 others died before they lived 800 days). Among the "female" mice, the record was 1,045 days, and 10 of them lived for more than 800 days. At the same time, both groups of mice were kept in the same sterile conditions with sufficient nutrition to exclude the influence of external factors on life expectancy.
The researchers also recorded the weight of the animals – at the age of 49 and 600 days. The modified mice turned out to be lighter and smaller than the usual ones. In addition, they had a more stable immune system due to an increase in the number of white blood cells – eosinophilic leukocytes.
Geneticists explain the difference in the lifespan of mice by suppressing the Rasgrf1 gene in "daughters of two mothers". It is usually expressed on the paternal inherited chromosome 9 associated with postpartum growth. However, it is not known for sure whether the Rasgrf1 gene is directly related to life expectancy. It is possible that other genes, usually transmitted from the father, also have an influence.
"Our results are consistent with models based on gender-determined selection of reproductive strategies. For example, male genes are injected to increase the body size of the required breed. Female genes allow you to optimize energy savings and the ability to avoid predators. Perhaps they are also responsible for the increase in life expectancy," the authors note.
Portal "Eternal youth" http://vechnayamolodost.ru03.12.2009