Against sexual chromosomes

2014/09/29 Galarraga Aiestaran, Ana - Elhuyar Zientzia

• Biologia
• Giza zientziak
• Genetika

She has XX, girl, has XY, boy. It is easy, too easy. It is true that without chromosomes And the embryo will become female, that is, the newborn will have the shape of a bride. And if you have Y chromosome, the embryo will become male and the newborn will be shaped as a boy, with testicles and penis. The Y chromosome contains the genes needed to develop the testicles and penis. Specifically, the SYR gene is the key to the development of the testicles and is responsible for turning on many other genes related to the physical characteristics of men.

However, things are not always so easy. For example, it can happen that the genes are mixed in the chromosomes and, for example, that a person with two X chromosomes has the male form because the SYR gene has moved to one of the X chromosomes (called translocation to the displacement of the genes). This person will be sterile, because he has no other genes needed to be a fertile male on his chromosomes, but his physical appearance does not correspond to what chromosomes “command”.

And this is just an example; there are many others who show that the xx-emea/xy-ar rating system is too simple. For example, although what sex chromosomes say matches physical appearance, it may happen that the brain says something else; or that the newborn is hermaphrodite...

Taking into account all these cases, does the denomination of sexual chromosome make sense? Sarah Richardson is in negative. Historian and scientific philosopher, he believes it is not correct to call X female chromosome and Y male chromosome. It is not correct and it is also easy. Chromosomes do not “command” so much and the thing is not so easy.

Published in the newspaper Berria.