Y chromosome is disappearing, but bad news ladies, the male is not
The human Y chromosome, which contains the SRY gene
responsible for male development, has been degenerating over time.
As the world progresses, biologists have shed light on
how the Y chromosome, one of the two sex chromosomes in humans, is on the cusp
of disappearing. The complete disappearance of this chromosome would mean the
end of the male offspring in the future.
WHAT IS Y CHROMOSOME?
The Y chromosome carries genes that are crucial for
the development of male reproductive tissues, such as the testes, and it
triggers the pathway for male sex determination.
Males typically have one X and one Y chromosome (XY),
while females have two X chromosomes (XX). The Y chromosome is much smaller
than the X chromosome and contains fewer genes.
WHAT\'S GOING ON WITH THE Y CHROMOSOME?
According to Jennifer A. Marshall Graves, a
distinguished Professor of Genetics and Vice Chancellor\'s Fellow, the human Y
chromosome is running out of time. In the last 300 million years, it has lost
1393 of its original 1438 genes, and at this rate it will lose the last 45 in a
mere 10 million years. The human Y chromosome, which contains the SRY gene
responsible for male development, has been degenerating over time. Scientists
estimate that at the current rate of gene loss, the Y chromosome could vanish
entirely within 11 million years. This prospect has raised concerns about the
future of human reproduction and species survival.
However, there is some hope.
A new study published in the Proceedings of the
National Academy of Science has revealed that the spiny rat, a rodent species
native to Japan, has evolved a new male-determining gene as its Y chromosome
disappeared. This discovery offers hope for human survival. The spiny rat\'s adaptation provides a potential
solution.
Researchers led by Asato Kuroiwa at Hokkaido
University found that most Y chromosome genes in spiny rats had relocated to
other chromosomes.
Crucially, they identified a small DNA duplication near
the SOX9 gene on chromosome 3, present in all males but absent in females. This
duplication appears to activate SOX9, taking over the role of the missing SRY
gene in male development.
The study shows that mammals can evolve alternative
sex-determining mechanisms when the Y chromosome is lost. This finding is
particularly significant given that another rodent species, the mole vole, has
also lost its Y chromosome and survived.
SURVIVAL IS KEY
While 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, ensuring the continuation of male offspring
production.
However, scientists caution that such evolutionary
changes could lead to the emergence of multiple sex-determining systems in
different human populations, potentially resulting in the formation of new
species.
As we face an uncertain future, this discovery
provides a glimmer of hope for human survival and opens new avenues for
research into sexual determination and evolution.
Prepared by:
Shelia Mohammed Jamal
Student in the Department of Nursing
Participant in scientific writing competition
