I know that DNA encodes proteins. Truthfully, everything besides that (including ‘what are proteins’) mostly wooshes over my head, but that’s not relevant because whenever I search this question I never even find it addressed anywhere.

The human body has, among other things, two hands each with five fingers, with a very particular bone structure. How are things like that encoded in DNA, and by what mechanisms does that DNA cause these features to be built the way they are? What makes two people have a different nose shape? Nearly everyone in my family has a mole on the left side of their face, how does that come about from DNA?

I’m sure there are many steps involved, but I don’t see how we go from creating proteins to reproducibly building a full organism with all the organs in the right places and the right shapes. Whenever I try to look this up, all of these intermediate steps are missing, so it basically seems like magic.

As I said, any explanation will most likely go over my head and I won’t be able to understand it fully, but I at least want to see an explanation. I’ll do my best to understand it of course.

  • NeatNit@discuss.tchncs.deOP
    17·
    8 months ago

    So in the end Hox genes are probably what you are looking for.

    Thank you! I will read up on that.

    If leg Hox genes are expressed where fruitfly normally have antennae, you get this horror:

    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 :)

    • Donjuanme@lemmy.world
      7·
      8 months ago

      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.