In the past two days, not only celebrities and Internet celebrities have rushed to the hot search, but also the news that Xiamen has broken out the illegal fetal sex identification interest chain, and the source of blood collection tools and test tubes is unclear. Seeing this, netizens immediately fried the pan, gender identification has not been allowed for a long time? How can it still be exposed? This is also very strange, right?
Seeing the gender identification, I thought of a sentence: "The only thing that limits my sudden wealth is the law"...
However, when it comes to gender identification, it is actually very simple, compared to b ultrasound, which requires special instruments, it is easier to use molecular biology, draw some blood, mention DNA, and then sequence, one hundred and eighty pieces are completed. Basically, most domestic laboratories have this ability, but it is interesting that people I know, basically no one does this, maybe the birth is the biggest surprise.
Let's talk about it today!
01, how does molecular biology detect fetal sex?
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At its core, it relies on cfDNA (circulating cell-free DNA).
Many people may be unfamiliar with this name, so let's spend some space here to introduce it.
Cells will go through many basic biological processes, such as replication proliferation, etc., naturally, including apoptosis, that is, cell programmed death, and these apoptosis cells will release their BODY DNA, as metabolism into the bloodstream, and eventually reused by the body, which is blood free DNA, that is, cfDNA.
In fact, cfDNA is present in all individuals, from infants and young children to the elderly.
The fetus is naturally no exception, and the fetal growth process is also accompanied by partial apoptosis, which releases DNA into the bloodstream after apoptosis.
And then there's the detection.
This is very simple, those who have a Y chromosome are male, and those who do not have it are female.
It just so happens that the y chromosome is a relatively special chromosome, and some of the sequences on it remain basically unchanged (which is also an important reason why we can do genetic tracing, and the molecular anthropology finds the human ancestor Adam did the same). ）
Of course, the fetal DNA entering the maternal blood is not always the same, but changes.
For example, from the beginning of pregnancy, the cfDNA in its blood is not the same at different points in time.
Overall, as the pregnancy cycle increases, more and more fetal cfDNA is detected in the blood, and the more feasible the results.
02, twisted transgender under patriarchy
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Not only gender screening, it is difficult to believe that in today's so-called technological prosperity, there are such a large number of people using "transfecation drugs" to take pregnant women, resulting in a large number of deformities.
The essence of the so-called "transfecation drug" is a "teratogenic" drug, which interferes with the development of the fetus and makes its external reproductive system develop deformity, such as making its clitoris overdeveloped to look like male genitalia, however, this thing is originally deformed development, and it has not developed into a real male genitalia, and the gender is still female.
The consequences of this deformed drug are not only the deformed development of the individual, but also the "deformed cultivation" of the family that does not conform to the facts, and both sides bear the pain, only for the profit of those who sell the deformity drug.
Behind this is a serious problem of son preference in China, and many people, whether from the family pension problem or the traditional "incense" inheritance problem, have led to the problem of son preference still exists. Although society has made a lot of efforts to change the problem of son preference, the problem of son preference that has been passed down for thousands of years has not been completely changed, and even to this day, the problem of bride price and the surname of future generations still exists.
So that, in 2019, the ratio of men and women aged 1-4 in China is as high as 113:100, while the world average is around 103-107, and this obvious gender imbalance may be behind the existence of early fetal sex screening and infanticide.
In fact, it is very clear that the human gender is determined at the moment the fertilized egg is formed, and we currently have no feasible way to change the gender, even the most cutting-edge science and technology can not achieve. Therefore, "reincarnation" in any sense is pseudoscience, and it is a child's guilt.
03, respect for life, gender freedom
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I don't know what to say, but I can only say, respect life.
What about the follow-up to illegal gender identification? It is often abortions that do not meet expectations. And the transsexual pill has brought a lot of pain to the child.
I hope more parents can be more enlightened and respect life.
Wang, Eric, et al. "Gestational age and maternal weight effects on fetal cell‐free DNA in maternal plasma." Prenatal diagnosis33.7 (2013): 662-666.