It is a general observation that women live longer than men. This fact applies to all the female population in the animal kingdom. However, the reasoning behind this is still not clear.
What’s known, however, is that women exhibit two X chromosomes. On the other hand, most men have one X and one Y chromosome. X chromosomes are packed with several protein-encoding agents. The Y chromosomes, on the other hand, show poorer genetic material and contain mainly the gene that determines male traits, for instance, the development of testes.
This is specific gene is termed as SRY gene, which is responsible for the development of testes. By digging into this deeper, researchers behind this latest study learned the possible reason behind why women outlive men.
What Does the Latest Research Say?
The latest investigation is conducted by the University of California, San Francisco (USCF). The study appears in the journal Aging Cell and concludes that the XX pairing of the chromosomes may be responsible for the extended lifespan among females.
That is not all though. Researchers say that the corresponding female hormones that the ovaries secrete also have a role to play in giving women their long lifespan. Put together, the XX chromosome composition along with the female hormones released by the ovaries may be the answer for why women live longer than men.
In the investigation, the researchers used a mouse model to comprehend this longevity advantage that females boast. The mice were genetically engineered in a manner that they fell into four classes.
The first class of mice had XX chromosome as well as developed ovaries. In the second class, the mice had XY chromosomes paired with developed testes. In another category, the mice had XX chromosome and testes. In the last category, the mice had XY chromosomes along with ovaries.
The researchers learned that mice with the XX chromosomes survived longer than the mice who had XY chromosomes irrespective of the presence of testes and ovaries. However, extended lifespan showed the best in the class of mice that had both XX chromosomal pairing and ovaries.
This simply translates into one thing – the XX chromosomes as well as the hormonal profile are responsible for the longevity among genders. In this regard, senior author of the study, Dr. Dena Dubal, pointed out, “This suggests that the hormones produced by female gonads increase lifespan in mice with two X chromosomes, either by influencing how the mouse develops or by activating certain biological pathways during their lives.”
The tests make it clear that both the hormonal profile and the genetic makeup of the females explain their long lifespan. In the study, the mice that lived long were the ones that had both XX chromosomal pairing and ovaries. In terms of a normal lifespan though, mice with the XX chromosome escaped early death. It is possible that this could be because of the inactive X chromosome making up for the active X chromosome if it is damaged or so.