Rare is the country or society where the life expectancy of men is greater than that of women. To explain this phenomenon we can pull intuition that perhaps tells us that men have a greater affinity for the activities that put them at risk, from tobacco consumption to recklessness at the wheel. Although there is something really in this explanation, this is only part of the story.
Genetics. Now, a team of researchers He has discovered A genetic mechanism that could be protecting women from cognitive deterioration associated with age. A mechanism that could also partly explain the greatest longevity of these in front of men.
Chromosomes turned off. The human being (As a general rule) It has 23 pairs of chromosomes, of which one is linked to our sex. In cases where a person inherits an X chromosome and a chromosome and, the second predominates and the first is latent, the sex that develops is the masculine.
In cases where two X chromosomes are inherited, one of them remains active and the other “sleep”, sex would be in this case the female. This is still a model and nature is capricious, sometimes it surprises us. The last surprise has been starred in some genes on this sleeping X chromosome: it turns out that the “dream” of these genes was not so deep.
In the hippocampus. In EK new study, the responsible team detected that about twenty genes on the silent X chromosome were reactivated In hippocampus cells of the mice in which the study was conducted. This activation was given in the subsequent stages of life and, to occur in the hippocampus and by the genes involved, it could imply a greater capacity to maintain cognitive abilities in old age.
“In typical aging, women have a brain that seems younger, with less cognitive deficits compared to men,” pointed in a press release Dena Dubal, co -author of the study. “These results show that the silent x females are later reactivated later in life, probably helping to slow down cognitive deterioration.”
The team indicates that, among the 22 genes that “escaped” silence, one stood out: PLP1 (Proteolipid Protein 1). This gene contributes to the creation of Myelina protective substance that surrounds neuronal connections and whose deterioration is linked to the appearance of diseases such as sclerosis.
Animal models. The team conducted its study in laboratory mice, combining two differentiated lineages from these to clearly differentiate the two X chromosomes and the two genes in each animal. By measuring gene expression in the animals hippocampus, they observed a reactivation that occurred in females at 20 months of life, something that would be equivalent to the 65 years of life in humans.
The details of the study were published In an article In the magazine Science Advances.
And in humans? Now, the team investigates whether this late activation is also given in older women. As explainedThere are reasons to think that it is the case. In some brain samples studied, it has been found that women had high levels of the PLP1 protein in the same regions as the study mice.
Image | Aris sfakianakis / Gadek et al. (2025)