How is the sex of a baby determined? It is not only because of their chromosomes!

Scientists have identified a specific gene that is involved in determining the gender of a child. The crucial gene can be found on the Y chromosome and is involved in the development of the testes (stock image)

How is the sex of a baby determined? It is not only because of their chromosomes! Scientists discover & # 39; regulator & # 39; chemicals that activate genes that are involved in the development of testicles

  • SRY is found on the male chromosome and this affects a protein called SOX9
  • SOX9 is regulated by enhancers and sex disorders that are caused by damage to them
  • Disruption of the expression of SOX9 can hinder the development of the testes

Scientists have identified a specific gene that is involved in determining the gender of a child.

The crucial gene can be found on the Y chromosome and is involved in the development of the testes.

If this is not true, scientists claim that this can lead to disorders in sexual development and incorrect development of the testicles.

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Scientists have identified a specific gene that is involved in determining the gender of a child. The crucial gene can be found on the Y chromosome and is involved in the development of the testes (stock image)

Scientists have identified a specific gene that is involved in determining the gender of a child. The crucial gene can be found on the Y chromosome and is involved in the development of the testes (stock image)

The presence of an X or Y chromosome is crucial in the determination of sex, but this Y-gel is an integral part of ensuring good development, scientists say.

Sex chromosomes called & # 39; XX & # 39; and & # 39; XY & # 39; are divorced, with girls wearing the first and boys the last.

A baby will be a girl if it carries an X chromosome and the embryo will be male if the fertilizing sperm has a Y chromosome.

Ms. Croft, a PhD student at the Murdoch Children's Research Institute in Melbourne, said: "The sex of a baby is determined by its chromosomes make-up at conception.

An embryo with two X chromosomes will become a girl, while an embryo with an X-Y combination results in a boy. & # 39;

However, the Australian team felt that this dynamic has an additional complication.

They discovered a & # 39; regulator & # 39; which controls the activity of some genes, which affect when a child is a man or a woman.

SRY is a gene found on the male chromosome (Y) and this directly affects a protein called SOX9.

Sex chromosomes called & # 39; XX & # 39; and & # 39; XY & # 39; are divorced, with girls wearing the first and boys the last. A & # 39; regulator & # 39; controls the activity of some genes that influence a child or a woman (stock image)

Sex chromosomes called & # 39; XX & # 39; and & # 39; XY & # 39; are divorced, with girls wearing the first and boys the last. A & # 39; regulator & # 39; controls the activity of some genes that influence a child or a woman (stock image)

Sex chromosomes called & # 39; XX & # 39; and & # 39; XY & # 39; are divorced, with girls wearing the first and boys the last. A & # 39; regulator & # 39; controls the activity of some genes that influence a child or a woman (stock image)

WHAT IS THE Y-CHROMOSOME AND WHY IS IT DROPS?

The Y chromosome is one of the two sex chromosomes found in humans – the other is the X chromosome.

It is the only chromosome in an organism that is not essential to life – after all, women survive just fine without one.

In humans, the 22 other pairs of chromosomes – the autosomes – are identical.

The Y chromosome contains more than 59 million building blocks of DNA and represents almost 2 percent of the total DNA in cells.

But the human Y chromosome is still one of the smallest in the genome.

It is worn by about half the sperm of a man and dictates whether a child will be male or female.

Nevertheless, it contains very little other important information.

And researchers think it will soon disappear.

The number of genes on the Y has fallen from more than 1,000 to about 50, a loss of more than 95 percent.

If the same degeneration continues, the Y chromosome will only have 4.6 million years to go before it completely disappears.

But the Y chromosome was not always that small.

It was once the size of the X chromosome and contained the same genes.

The problem, however, is that Y chromosomes are found only as a single copy, from fathers to their sons, instead of a few

This means that genes on the Y chromosome can not undergo anything known as "genetic recombination."

This is a switch of genes that takes place in every generation that helps eliminate harmful gene mutations.

Professor Sinclair, a pediatrician at the University of Melbourne, said that the SOX9 gene is being regulated by enhancers – and that sexual development disorders are caused by damage to them.

If the expression of SOX9 is disrupted, this may impede the development of the testes, according to the article published in Nature Communications.

Development biologist Brittany Croft said: # The Y chromosome carries a crucial gene called SRY that acts on another gene called SOX9 to initiate the development of testicles in the embryo.

• High levels of the SOX9 gene are required for normal testis development. However, if there is some disruption of SOX9 activity and only low values ​​are present, there will not develop a testis that results in a baby with a disorder in sexual development. & # 39;

Four patients with disorders in sexual development were studied and could shed new light on the genetic causes of disorders in sexual development.

Lead author Andrew Sinclair explained: & # 39; These regulatory DNA segments are called enhancers.

& # 39; If these enhancers who control the testis genes are disrupted, this can lead to a baby being born with a disorder in sexual development.

We discovered three enhancers that together ensure that the SOX9 gene is activated at a high level in an XY embryo – leading to normal testis and male development.

Importantly, we identified XX patients who normally had ovaries and were female, but who carried additional copies of these enhancers – high levels of SOX9 – and developed testes instead.

In addition, we found XY patients who had lost these SOX9 enhancers – low levels of SOX9 – and developed ovaries instead of testes. & # 39;

The trio of enhancers is required for normal testes and male development.

Professor Sinclair said that on the other side of the human genome there are about one million amplifiers that control about 22,000 genes.

He added: & # 39; These enhancers lie on the DNA but outside genes, in regions that were previously referred to as junk DNA or dark matter.

The key to diagnosing many ailments is found in these amplifiers that hide in the poorly understood dark matter of our DNA. & # 39;

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