According to a recent research, the extinction of Y chromosome has come to the fore. As you know, Y chromosome plays an important role in determining the gender of a male. This research is quite scary. Because if this research is to be believed, then in future more girls will be born. Because Y chromosome has reached the verge of extinction.
How is the gender of the foetus decided?
Let us understand in detail in this article how chromosome Y works. Also, we will know how it reached the verge of extinction. Most mammals, that is, those who breastfeed their children, have 2 X chromosomes in them, i.e. women or female animals. Whereas males have one X and one Y chromosome. When there is a fusion between egg and sperm, then the SRY gene is present. Then the embryo is male.
The SRY gene becomes active after about 12 weeks of pregnancy. By looking at it, we can find out whether the baby growing in the fetus is a male or a female. The child who produces the male hormone testosterone is born as a male.
This is how chromosomes work in mammals
The SRY gene was discovered in 1990 and it was found that it activates SOX9. Which triggers the development of male gender in any mammals. That is, if this gene is present, then the child growing in the womb is male. Why is the Y chromosome disappearing? In the 166 million years since humans and platypus separated, the Y chromosome has lost a significant number of active genes, which has decreased from 900 to only 55. This is a loss of about five genes every million years. If this continues, then in the coming years the Y chromosome may disappear completely in the next 11 million years.
The X chromosome contains about 900 genes with multiple functions, while the Y has about 55 genes of which only 27 are male-specific. Most of the Y is made up of repetitive ‘junk DNA’. With such an unstable structure, the Y chromosome is at risk of disappearing completely over the course of several generations, according to a report in The Week.
What was revealed in the research report
Genetics expert Professor Jenny Graves explains that the reduction in the size of the Y chromosome is not a new phenomenon. She explains that in the platypus, the XY chromosome pair looks like a normal chromosome with equal members. This suggests that the mammalian X and Y were a normal pair of chromosomes until very recently, Graves said. In two rodent lineages – the mole vole of eastern Europe and the spiny rat of Japan – the Y chromosome had already been lost. In these species, both males and females retain the X chromosome, but the Y chromosome and the SRY gene have disappeared.
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