until now, I always assumed that genes for sperm were on the Y chromosome, but I guess they’re not?
ada@lemmy.blahaj.zone 1 month ago
By definition, two people of different sexes can’t be clones
onipa@feddit.org 1 month ago
ada@lemmy.blahaj.zone 1 month ago
The Y chromosome doesn’t carry much of anything. It’s basically just a carrier for the SRY gene, and in most cases, it’s that gene that triggers the majority of the sexual differentiation that occurs in early development. The actual “code” for what develops and how it develops is there for male and female differentiation in all humans, and it’s hormones and other factors that control whether or not that genetic code is expressed.
And in this case, we’re talking about stem cells (ie, a cell that has the potential to develop in to any cell, but hasn’t yet done so), and then artificially triggering those stem cell to develop in to sperm cells. A trick that can be done because the genetic code for it to do so is already there if the conditions are right.
As an aside, this is also why hormone replacement for trans people lets them develop secondary sexual characteristics that they wouldn’t otherwise develop. The code was already there, it just takes the right trigger to get the code expressing (in this case, hormones)
JasonDJ@lemmy.zip 1 month ago
So you’re telling me that somewhere in my biological code is my mom’s tits. And if I just take some estrogen, I can have my mom’s tits?
thoughtfuldragon@lemmy.blahaj.zone 1 month ago
Your dad’s tits are there too. You might get his.
homura1650@lemmy.world 1 month ago
The Y chromosome does a bit more than just carry the SRY gene.
There is a condition where a father’s SRY gene gets transfered to the X chromosome of a sperm, resulting in a child who is XX and SRY positive. [0]
In all known cases, such men are infertile. Fertility treatment is the main source of diagnoses for this, as that is typically the only symptom.
[0] This is de la Chapelle syndrome, although that syndrome also covers an even rarer situation of an XX SRY-negative child developing as a male.
FenrirIII@lemmy.world 1 month ago
Yet. Let’s have fun with the topic.
If not exactly identical, would they be like twins?
okwhateverdude@lemmy.world 1 month ago
So a fraternal twin of yourself? Pretty sure it wouldn’t be masturbation at that point, but straight up incest.
ada@lemmy.blahaj.zone 1 month ago
If not exactly identical, would they be like twins?
The parents? Basically, as the only difference between them is a single chromosome out of the 26 we carry. There are slight genetic differences between identical twins, due to the accrual of mutations during cell division, but it’s smaller than a full different chromosome. That’s splitting hairs though, because both identical twins and our theoretical clones would be functionally identical.
If not exactly identical, would they be like twins?
If you mean the parents and their child, then they’d be somewhere between identical twin and regular sibling in terms of genetic similarity. Regular siblings on average, share about 50% DNA. Identical twins share 100% DNA. Our theoretical child in this scenario would share around 75% of their parents DNA
andrewrgross@slrpnk.net 1 month ago
I think this is mostly correct.
I think what you mean is that each chromosome has two paired arms that contain alternate versions of functionally the same content. It’s like if you had two cookbooks by different authors that had the same chapters and dishes, but different content. The two versions aren’t in the two strands of DNA, they’re in the two arms of each chromosome.
The problem is that during reproduction, each parent randomly contributes one of the two chromosomes. When each sperm and each egg is made, there’s a 50-50 chance that it gets arm 1 or arm 2 from each chromosome.
If you took a sperm cell that had received all of its content exclusively from arm 1 with an egg that contained content exclusively from arm 2, then I believe that when they fused they would produce what could be called a clone. Some might take issue and point out that the content from the arms gets mixed between the two during this process, so each arm isn’t identical to the first, but we can set that aside for now, I think. The offspring would have all the genes of the original person, and presumably would look identical to them, like a twin.
The problem is that if you were to engage in this exercise (which is tagged “selfcest” if you’re looking for erotic stories about this stuff) in real life, you’d encounter the same problem with incestual reproduction: unless the sperm and egg were prepared in a lab or using magic to ensure that each arm of each chromosome went into a different sex cell, you’d inevitably have cases where the sperm and egg both received their chromosome from the same arm. This means that the offspring wouldn’t have the full duplicated genome of the original parent; on those chromosomes, they’d have half of the parent’s full compliment of genes. And we rely on having two different copies as backups. This is why interbreeding produces birth defects and lower fitness: you miss out on backup copies.
To summarize, you wouldn’t faithfully duplicate yourself, you’d duplicate most of yourself with
So – assuming the offspring was viable – you’d kind of get a lower quality clone: the offspring would probably look like a twin of the original, but they might have worse eyesight. They might have thin, anemic blood. They might have oilier skin and hair, or dryer, itchier skin and hair.
Rhynoplaz@lemmy.world 1 month ago
“I like pizza, Steve!”
I hope there are others out there that still recognize and use this movie quote 30 years later.