How much data does DNA have for things like skin and fur colors, especially in the case of weight gain?

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Sorry if this doesn’t make sense or is dumb

So to my understanding, your dna contains all of the code for how your phenotypes are expressed, including in your skin of course. Like where moles/birthmarks go, and for animals, how different fur colors manifest. Pigment and stuff is programmed to go to specific areas and things like that

But how much data is there? Because if someone gains a lot of weight, they also gain a lot of new skin. Does your dna just have an endless pattern for what features your skin will have? Or when an animal is really overweight, how does the dna just keep on generating a fur pattern indefinitely? I can understand when it comes to skin how maybe moles and things are a separate manifestation, but to my knowledge fur color is very tied to pigment sources placed in a pattern. It’s not random, because the colors are never just scattered without reason. But how does it decide in what manner to continue the pattern? Of course DNA is a finite thing, so does it eventually just loop back around? A repeating pattern, reusing data?

Sorry if I’m totally misunderstanding how this works lol

In: Biology

4 Answers

Anonymous 0 Comments

You’ve basically got it! DNA doesn’t have an endless pattern; it actually follows specific instructions coded in your genes. Think of it like a blueprint. For skin and fur, your DNA has the “master plan” for color and patterns. When you gain weight, new skin or fur cells follow the existing genetic blueprint so the pattern continues seamlessly. It’s not infinite data, but more like a well-designed map that keeps everything consistent. And yes, there’s repetition, but it’s not that it loops; it’s just really good at distributing the pattern evenly! 溺😊

Anonymous 0 Comments

I am not sure of the right answer, but I think I can explain a flaw in your thinking. DNA is not a blueprint of your body. DNA is more like a set of instructions to build the things that build your body.

Consider the examples: A city blueprint would be a map with all the roads and building and stores already laid out. If the city needed to grow the builders would just consult the map. This would be DNA as a blueprint.

Now imagine a city with rules like 1. Don’t put sewage next to schools. 2. Buildings should be at least 3 stories tall. 3. If people are hungry build a grocery store. If the city needed to expand, the builders would just follow the rules. This would be DNA as instructions.

Anonymous 0 Comments

You’ve asked a really good question that does have an example in the calico cat!

1. When a zygote/fetus is first formed, that one cell has two copies of each chromosome, but, each chromosome copy may have a different version of a gene (these versions are called “alleles”) such that one copy codes for one hair color, and another copy codes for a different color. **Cat coat genetics are actually a little more complicated than this but I’ll keep it simple**. If the cat has *black* on both chromosomes, it is a black cat. If it has *orange* on both, it is a ginger cat. If it has *black* on one, *orange* on the other, it has a brown coat.

2. As cells of the zygote proliferate (grow in number) and differentiate (turn into specific body parts), these alleles become important only if they affect that cell. Like, a cat’s liver cell doesn’t give a crap about coat color, but the fur-growing cell needs to know – what color am I? So yes, areas of the body that grow and “fill in” just copy themselves from what is already there. A tooth doesn’t randomly grow out of the skin that is growing, because tooth genes aren’t “on” in the skin. (And when this happens, which does rarely, it’s a sign of a serious disorder in those cells. They’re reading the wrong chapter in the manual).

3. There is a fascinating thing that happens in female zygotes: [Barr-body inactivation](https://en.wikipedia.org/wiki/Barr_body). Females have two X-chromosomes, and under certain circumstances, early on in fetal development, one of those two chromosomes in a cell will just shrivel up and close down shop. For these cells, and all the cells that proliferate from it, the remaining X-chromosome becomes the sole genetic source for those genes down the line. So imagine you have a female cat zygote, and it has *black* fur gene on one of its X-chromosome, and *orange* on the other; after the first cell division, both of the daughter cells ‘turn-off’ one X-chromosome, such that one is now just *black* and the other cell is *orange*. As those cells develop into tissues, the cat will present as black on one half, right on the other. This happens a lot with cats because their coat color genes are basically “white or color?” plus “if color, then black or ginger” and then… kind of a volume slider bar for intensity of color. So with a cat that has both alleles for those first two genes, and color intensity set to full, you can end up with patches of different colors (black, orange, and white). Each patch is derived from that moment when its first source cell turned one of those X-chromosomes off. We call this coat pattern “calico”. Such Barr-body-related events in development have a lot of complex and interesting outcomes.

4. So as a calico kitten grows and gains weight, their patches stay mostly the same and just fill in from the inside. Similarly, a mole on human skin is a skin cell that randomly decided to produce a lot of melanin, and then all the cells proliferated from it followed those instructions (I don’t think moles are Barr-bodied-related events, though).

Anonymous 0 Comments

>So to my understanding, your dna contains all of the code for how your phenotypes are expressed, including in your skin of course. Like where moles/birthmarks go, and for animals, how different fur colors manifest. Pigment and stuff is programmed to go to specific areas and things like that

DNA simply encodes proteins (we’ll just skip over the can of worms that is noncoding DNA), which is to say, strictly the instructions to make them. **There is no information in there dictating the fate of proteins after they are produced.**

I get the feeling you’re approaching this from a computer/code analogy sort of view, so consider it this way. Every protein-coding stretch of DNA (gene) is like a constructor function. When the function is triggered, an instance of its object product is made (DNA is transcribed into RNA and RNA is translated into protein). These objects (proteins) can actually *do* stuff during runtime of our program (life of the cell). There are also objects (transcription factors) that control the triggering of particular sets of constructor functions. Overall, all the complex outcomes of our program at runtime is a result of the interactions between these objects; it’s classic [emergent behavior](https://en.wikipedia.org/wiki/Emergence). And on top of that, every single cell has a *complete set of constructor functions (genome)* and starts off with some running objects the mother cell it divided from.