Dark hair color in men, was associated with early pubertatnom and short life

Analyzing the genomes of hundreds of thousands of men and women, researchers found the genetic correlation between the time of onset of puberty and a variety of signs. It turned out that late puberty correlates with light hair color, as well as with a reduced risk of certain age-related diseases and a longer life. What mechanism this is achieved is unclear, but scientists tend to blame it all on the pituitary gland. Work published in the journal Nature Communications.

Puberty in humans does not occur at the same time — contribute to its onset and contribute genes and environment. Biologists have long suspected that the time of onset of puberty affect the further life and human health. At least, there is already evidence that early maturation increases the risk of several diseaseslike cancer and type 2 diabetes. What kind of mechanism binds these two facts, is unclear. In addition, most of these works are held at women — partly because they are easier to fix the point of beginning of puberty (first menstruation).

Scientists led by John Perry (John Perry) from the School of clinical medicine Cambridge University considered the gender imbalance in such studies and was used by the British Biobank (UK Biobank) is a large database of genetic data to select the genomes 207126 men and look for genes that may be associated with the time of puberty. Early puberty the researchers evaluated the questionnaires: subjects were asked to recall when they had the first signs of — breaking voice and facial hair earlier or later than their peers.

In previous works scientists have identifiedwhich genes are correlated with the start time of menstruation in women. Of these 266 328 genes were associated with early and 276 — with the late appearance of facial hair in men. Their results, the researchers confirmed in two samples — 55871 men from the database of 23andMe and several thousands of boys from a longitudinal study ALSPAC. In all these cases it appeared that a number of gene variants does correlate with the time of onset of puberty.

Thus, at least some of the genetic mechanisms responsible for sexual maturation, should be the same for men and women. Nevertheless, some of these mechanisms should be different: in the sample 23andMe 15 of 387 the most important genetic variants for women and 5 of the 76 most important for men the other sex did not correlate with the time of puberty.

Among the gene variants, which in men are correlated with the time of puberty, the researchers noted three, which coexist in the genome near genes associated with pigmentation of skin and hair. This seems logical, since during puberty the skin and hair often darken. However, the relationship between the intensity of pigmentation and maturation time still no one found. The authors analyzed data on 179954 men from the British Biobank and found that the media has a natural red, dark brown and black hair puberty begins earlier than in blondes, and light brown (p < 0.05). The same effect they have confirmed 238195 women.

Finally, the researchers calculated a genetic correlation between start time of puberty and the risk of developing diseases in men (since it is already known in women). They found that early puberty correlated with the risk of diseases of the cardiovascular system, diabetes of the second type, as well as alcohol abuse and Smoking. Correlation with risk of prostate cancer they found, but it turned out that every year of delay of puberty is correlated with an additional 9 months of life.

The authors do not aim to identify detailed mechanisms of those laws about which they write. However, they hypothesized that the color of the hair and puberty can be linked through the pituitary gland: this gland secretes gonadotropin at the same time (i.e. regulating the development of the gonads) hormones and melanocyte-stimulating hormone, which affects pigmentation. It can be assumed that the production of these hormones can participate the same enzymes.

From the editor

As for the connection of puberty with life expectancy, despite the lack of known mechanisms, this dependency does not seem surprising. At least, that many animals slow development is associated with a long life. Most of the known species-centenarians are characterized by a long maturation of the young and late onset of sexual activity. It is therefore logical that this pattern can work within a single view.

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