98
How does DNA decide the shape of the body?
(discuss.tchncs.de)
you are viewing a single comment's thread
view the rest of the comments
view the rest of the comments
this post was submitted on 27 Apr 2024
98 points (96.2% liked)
No Stupid Questions
35764 readers
1001 users here now
No such thing. Ask away!
!nostupidquestions is a community dedicated to being helpful and answering each others' questions on various topics.
The rules for posting and commenting, besides the rules defined here for lemmy.world, are as follows:
Rules (interactive)
Rule 1- All posts must be legitimate questions. All post titles must include a question.
All posts must be legitimate questions, and all post titles must include a question. Questions that are joke or trolling questions, memes, song lyrics as title, etc. are not allowed here. See Rule 6 for all exceptions.
Rule 2- Your question subject cannot be illegal or NSFW material.
Your question subject cannot be illegal or NSFW material. You will be warned first, banned second.
Rule 3- Do not seek mental, medical and professional help here.
Do not seek mental, medical and professional help here. Breaking this rule will not get you or your post removed, but it will put you at risk, and possibly in danger.
Rule 4- No self promotion or upvote-farming of any kind.
That's it.
Rule 5- No baiting or sealioning or promoting an agenda.
Questions which, instead of being of an innocuous nature, are specifically intended (based on reports and in the opinion of our crack moderation team) to bait users into ideological wars on charged political topics will be removed and the authors warned - or banned - depending on severity.
Rule 6- Regarding META posts and joke questions.
Provided it is about the community itself, you may post non-question posts using the [META] tag on your post title.
On fridays, you are allowed to post meme and troll questions, on the condition that it's in text format only, and conforms with our other rules. These posts MUST include the [NSQ Friday] tag in their title.
If you post a serious question on friday and are looking only for legitimate answers, then please include the [Serious] tag on your post. Irrelevant replies will then be removed by moderators.
Rule 7- You can't intentionally annoy, mock, or harass other members.
If you intentionally annoy, mock, harass, or discriminate against any individual member, you will be removed.
Likewise, if you are a member, sympathiser or a resemblant of a movement that is known to largely hate, mock, discriminate against, and/or want to take lives of a group of people, and you were provably vocal about your hate, then you will be banned on sight.
Rule 8- All comments should try to stay relevant to their parent content.
Rule 9- Reposts from other platforms are not allowed.
Let everyone have their own content.
Rule 10- Majority of bots aren't allowed to participate here.
Credits
Our breathtaking icon was bestowed upon us by @Cevilia!
The greatest banner of all time: by @TheOneWithTheHair!
founded 1 year ago
MODERATORS
I recently had a course in developmental biology and this is what I can remember the best:
From the moment of fertilization, the egg has a 'polarity', thus a direction like up and down, left and right etc. This can be established by e.g. the entry point of the sperm or protein produced by the mother in one side of the egg. From here on out protein gradients and interactions on cell membranes specify where cells are and thus what kind of tissue they should become
This early polarity leads to a certain pattern of cell division. An important part of this is the folding in of tissue layers called gastrulation, creating the beginning for the gastrointestinal tract.
In vertebrates a streak starts to form in the embryo. This is the start of the vertebrae and the neural tube in it. Also blocks of cells called somites start to form. These blocks are very important for all kinds of tissues in the body.
Hox genes make the cells in somites get an identity like head, arm etc. So in the end Hox genes are probably what you are looking for. If leg Hox genes are expressed where fruitfly normally have antennae, you get this horror:
Thank you! I will read up on that.
So, a core part of my question is what causes certain genes to be expressed in certain places in the body, and specifically how this comes about from genetics alone (i.e. not artificially in lab experiments). In my past searches I did find some info about forcing gene expression in places where it wouldn't normally happen, which creates horrors similar to the one you shared, but I never found an answer for how this is controlled in natural development. Hox genes seem to be the answer I'm looking for :)
Here’s a fantastic and entertaining short video on how it works: https://youtu.be/ydqReeTV_vk?si=AyKJPZIzwaSCvZxv
Huh… it never ceases to amaze me how many quite large channels that I would absolutely enjoy, like this, are not recommended to me. Even though I watch content very similar and live on YT.
Thanks for sharing.
How is this so good hole crap
I have no idea, he operates on his own level. All of his videos are top quality.
I would start by looking at plant genetics, if you think about it they; are simpler to understand, they never stop growing (expressing those genes), are much less specialized (cells cannot just be told that they are certain organs because of their surrounding cells, if a root penetrates the surface it no longer needs to be a root right?) actually has more factors in deciding how to specialize (animal cells only need to orient themselves up once, plants cells are constantly orienting themselves, both against gravity, and the wind, and sometimes in response to other plants, these things all have generic controls).
Plant biology is a great stepping stone to a lot of what you're looking for.
DNA is like the secret recipe at KFC (except it has 40 spices with names for 64, but quite a few of those names are homonyms for the same spice, and 3 of those spices aren't spices but instructions for when to stop adding spices), with a, millions of peoples rely on it, from cashier's and cooks, to janitors franchisees, CEOs and builders, some of these are more hands on with the recipe, while others are way down the line, but none of them have ever seen the recipe first hand. The DNA is kept from harm by being hidden away where only DNA readers and multipliers have access to it, everything that is produced by the DNA gets (this metaphor is so tortured) broken down into what spices are needed in which order, the spice mixers and bakers are pretty damn familiar with the instructions, those would be RNA and proteins, but just because they get good instructions doesn't mean they're free from outside influence, they're outside of the vault after all.
By the way, in case you'd have a guess for the answer:
If scientists really wanted to, throwing all questions of ethics out the window, would it be possible to genetically engineer a person with four arms instead of two, kinda like Goro? Does our current understanding of this go far enough to make deliberate changes like that? And would that baby be able to develop in a normal woman's pregnancy?
No, and no. My PhD thesis was on gene delivery. We're barely getting into the simplest modifications for disease treatment. Multigene stuff, and spatiotemporal control is still a ways off.
I would say sort of. They could do it, but the result wouldn't survive very long. Probably not even to birth.
I'd guess no, the number of digits and limbs is conserved very well across tetrapods (it's in their name after all). Fucking with the amount of limbs will probably lead to some developmental errors in the early embryo.