Have you ever thought of why you were born a boy or a girl? Well, what we have learnt so far is that girls have sex chromosomes XX, and boys will have sex chromosomes XY from their parents. However, studies in Nature magazine showed that sometimes embryos with both X and Y chromosomes turns out to develop ovaries and in the end...become girls. And it is said that this phenomenon can affect up to 1 in 20000 genetic males.
The key to this phenomenon is a gene called Sox9, which is involved in the formation of the testes. If Sox9 is somehow switched on in female embryos, it can cause male testes to be formed, and vice versa for male embryos. The malfunctioning of this gene is one of the culprit responsible in causing sex reversal or intersex cases in humans, and patients affected by this gene defect has a higher risk of getting ovarian tumors.
Scientists are speculating the possibility of manipulating Sox9 after birth, and so far they have found out that Sox9 in genetically engineered mice is controlled by two other genes, one of which is in the Y chromosome. When either of them is defective, Sox9 switches off and the embryo develops ovaries.
Robin Lovell-Badge, a biologist at London's MRC National Institute for Medical Research believes that the findings in mice apply to humans as well, and with further analysis, scientists may discover ways to reassign genders later in life.
(Wai Yien, Lau 41504378)
Reference:
Scientific American
http://www.sciam.com/article.cfm?id=how-boys-become-boys-and
The key to this phenomenon is a gene called Sox9, which is involved in the formation of the testes. If Sox9 is somehow switched on in female embryos, it can cause male testes to be formed, and vice versa for male embryos. The malfunctioning of this gene is one of the culprit responsible in causing sex reversal or intersex cases in humans, and patients affected by this gene defect has a higher risk of getting ovarian tumors.
Scientists are speculating the possibility of manipulating Sox9 after birth, and so far they have found out that Sox9 in genetically engineered mice is controlled by two other genes, one of which is in the Y chromosome. When either of them is defective, Sox9 switches off and the embryo develops ovaries.
Robin Lovell-Badge, a biologist at London's MRC National Institute for Medical Research believes that the findings in mice apply to humans as well, and with further analysis, scientists may discover ways to reassign genders later in life.
(Wai Yien, Lau 41504378)
Reference:
Scientific American
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