The magic enhancer Enh13 acts directly on the gender-determining protein gene Sox9 removal.

As a child in a popular book read that there is only one male fish in the red herring, when the male fish leaves the group, there will be a female fish in the group slowly become male fish.
wow, this shocked me at the time or a little cake, gender is such an important thing, can also be so casual? A study published this week in the journal Science has shaken my worldview a little bit, and the original fork in the biological sex is standing on a "junk gene" with only 500 bases long! The study, from the Francis Crick Institute in the Uk, and the team of Professor Robin Lovell-Badge, found a magical enhancer Enh13, which acts directly on the most important gender-determining protein gene, Sox9, which removes the "junk gene" that does not encode any protein and the male mice with XY chromosomes develop into "females" with a full set of genitals! Both mice have female genitalia, but guess what is XY, that's XX? Professor Robin Lovell-Badge has a ten-tenths of a say on the question of how gender comes about.
1991, he led a team that discovered the gender-determining gene sry on the mammalian Y chromosome.
the gene-coded protein is called the gender-determining region Y protein (SRY), also known as the testicular decision factor (TDF).
look at the name of the protein, which affects the formation of male genitalia such as the testicles.
in fact, in the early stages of development, the gender-related part is very vague, those cells have the potential for differentiation between the sexes, both can grow into testicles, may also grow into the uterus.
if the development process is not interfered with, then all embryos will actually grow into females, the world will only have girls.
SRY as a transcription factor, the most important thing to do is to regulate Sox9.
Sox9 directly controls the initiation of male development, the appearance of male genitalia, through a series of genetic effects downstream.
in humans, The disease caused by Sox9 hybrid defects is called presuptaral dysplasia, and 70 percent of men (XY) people exhibit female traits.
in the process, there are many "junk genes" at work.
of all DNA, the DNA of the encoded protein actually accounts for only 2%, and the remaining 98% does not seem to work.
scientists for a long time couldn't figure out what the DNA was all about, so they called them "junk genes."
Of course, we now know that these non-coding DNAs also have their own positions, such as the enhancer we are talking about today, a DNA sequence that increases the frequency of gene transcription.
there are about 1 million enhanceos in the entire genome that regulate nearly 21,000 genes.
at this rate, Sox9 must also have a number of "supporters" spread across 2 million base pairs.
To find the strongest of these, Professor Robin Lovell-Badge and colleagues used a combination of sequencing techniques to screen genes for early embryonic development, from none to 16 to 1, to identify the only essential part of the gene.
this piece of DNA, called Enh13, is small, only 557bp long, far from Sox9, separated by more than half a million base pairs.
is such a small gene, even decided that the sex in the end "is male or female"! The researchers tried to knock out Enh13 of the XY mouse embryo and were surprised to find that the Sox9 protein level dropped below 25% of normal! This level can not be ignored by the researchers guess, these XY mice grow up, afraid to become "little girls"! Sure enough, after growing up into a mouse, XY mice and XX mice simply silly do not know, they not only outside the genitals of a look, the body is also completely growing a set of female reproductive organs! In particular, en13 is quite conservative in mammals and has binding sites to many of the transcribed factors associated with gender development, and it is reasonable to believe that Enh13 also plays such a key role in human development. Professor Robin Lovell-Badge,
, said: "We have shown for the first time that changing the non-coding areas of DNA can reverse gender.
", we believe enh13 may be linked to human gender dysplasia and may be used to help diagnose these cases.
" he added that at least half of human systogenies have unknown genetic causes, and that the analysis of such patients focused on the coding gene, ignoring non-coding genes. Dr. Nitzan Gonen, the first author of the
, also said it was incredible that a single enhancer could control such an extremely important event as gender.
now it seems that we have to study what gems are hidden in the 98% of the "junk gene" ... Source: Five-line spectrum.