Trump said sex is determined at conception, and I see lots of queer people jumping to say this means everyone's female. I'm going to explain why it's scientifically unaccurate, and how this misconception lies on misogynistic ground. 🧵 - ThreadSky

ankou.bsky.social • 44 days ago

Trump said sex is determined at conception, and I see lots of queer people jumping to say this means everyone's female.

I'm going to explain why it's scientifically unaccurate, and how this misconception lies on misogynistic ground.

🧵

Comments

ankou.bsky.social•44 days ago

First, this would mean everyone's sex-neutral not female, because at conception, the sex organs are undeterminated, not female.Thus, we're all non binary 😁

Joke aside,I know a lot of you, me included, learned at school that female is the default mode of sex differenciation.

We know it's not true.

ankou.bsky.social•44 days ago

Ovarian differenciation has been taught to be the "default mode" : with SRY gene (carry by the chromosome y) : the undeterminated sex organ developps into testes. Without the SRY gene, they turn into ovaries.

But 2006 studies showed there actually is 2 genetic pathway that suppress each other,

ankou.bsky.social•44 days ago

meaning when you have an Y, there is a suppression of the ovaries pathway, and when you have a second X, there is a suppression of the testes pathway.

In other words, there is no default mode but two distincts switch.

But where this misconception is coming from ?

ankou.bsky.social•44 days ago

Male differenciation was studied in 1947 through a series of experiments,mostly castrations and transplants of testes.
This study was andro-centred (no experiment with ovaries)and concluded for decades that this was a female by default mode.

The reverse experiments were conducted in 1972-25y later.

ankou.bsky.social•44 days ago

Then, it was discovered that :

-testes differenciation is hormone-induced (if you castrate a male fœtus, it doesn't developps male characteristics)

-ovaries differenciation is not hormone-induced.
(if you castrate a female fœtus, it does developps female characteristics)

ankou.bsky.social•44 days ago

BUT instead of looking for what exactly is responsible for the ovaries differenciation, we settled on the "default mode story".

There were A LOT of studies around the Y chromosome and the SRY gene, but very few studies tried to find the "unknown ovarian genes".

chloe-mayere.bsky.social•44 days ago

Thanks for this super thread :-)
And also we are actively looking for determinants of the ovarian pathway! The most recent update is about the +&-Kts isoforms of the Wt1 gene ! Check it out here: https://www.science.org/doi/10.1126/science.add8831

ankou.bsky.social•44 days ago

Thanks a lot !! I'll keep myself updated !

Comments

Posting Rules

Reply