As the world progresses, biologists have highlighted how the Y chromosome, which is one of the two sex chromosomes in humans, is on the verge of extinction. The complete disappearance of this chromosome would mean the end of male offspring in the future.
However, there is some hope.
A new study published in the Proceedings of the National Academy of Sciences reveals that the spiny rat, a rodent species found in Japan, has evolved a new male-determining gene because its Y chromosome has disappeared.
This discovery offers hope for human survival, as our own Y chromosome faces the risk of extinction in the coming millions of years.
What is the Y chromosome?
The Y chromosome contains genes that are important for the development of male reproductive tissues, such as the testes, and pave the way for male sex determination.
Men typically have one X and one Y chromosome (XY), while women have two X chromosomes (XX). The Y chromosome is much smaller than the X chromosome and contains fewer genes.
What's up with the Y chromosome?
According to Jennifer A. Marshall Graves, Distinguished Professor of Genetics and Vice Chancellor Fellow, the human Y chromosome is running out of time. Over the past 300 million years, it has lost 1393 of its original 1438 genes, and at this rate it will lose the last 45 genes in just 10 million years.
The human Y chromosome, which contains the SRY gene responsible for male development, has been degrading over time.
Scientists estimate that at the current rate of gene loss, the Y chromosome could disappear completely within 11 million years. This possibility has raised concerns about the future of human reproduction and the survival of the species.
have hope
The adaptations of the spiny rat offer a possible solution.
Researchers led by Asato Kuroiwa at Hokkaido University found that most of the Y chromosome genes in spiny mice had been moved to other chromosomes.
Importantly, they identified a small DNA duplication near the SOX9 gene on chromosome 3, which is present in all men but absent in women. This duplication activates SOX9, which plays the role of the missing SRY gene in male development.
The study shows that mammals can develop alternative sex determination mechanisms when they lose the Y chromosome. This finding is particularly important because another rodent species, the mole vole, has also lost its Y chromosome and survived.
survival is the key
Although the potential loss of the human Y chromosome remains a concern, this research suggests that our species could potentially evolve a new sex-determining gene, allowing us to continue producing male offspring.
However, scientists caution that such evolutionary changes could lead to multiple sex-determination systems emerging in different human populations, possibly resulting in the creation of new species.
As we face an uncertain future, this discovery offers a ray of hope for human survival and opens new avenues for research on sex determination and development.