Could human DNA be every type of plant, animal, or microbe DNA?

I'm asking in order to understand if the only difference between the DNA of all living things is merely the arrangement or sequence of their letters. This is more of a curiosity question, not about sci-fi or current feasibility.

Could the letters of a human DNA be reordered so it's identical to the DNA of any animal, plant, or microbe and fully compatible? (in a purely theoretical way)

syfry said:

TL;DR Summary: Hypothetically, if something could somehow reorder the letters in human DNA, can it be compatible as a functional DNA in any animal, plant, or microbe that has a perfectly matching DNA?

I'm asking in order to understand if the only difference between the DNA of all living things is merely the arrangement or sequence of their letters. This is more of a curiosity question, not about sci-fi or current feasibility.

Could the letters of a human DNA be reordered so it's identical to the DNA of any animal, plant, or microbe and fully compatible? (in a purely theoretical way)

DNA of different organisms have different lengths and different ratios of the "letters".

Basically, you should be able to match any DNA sequence.
However, as @Hill noted, the length of DNAs can vary. This may not be a problem since the DNA in eukaryotes ((like humans, plants animals, fungi and some microbes like ciliates) comes in huge pieces.
The DNA of prokaryotes (bacteria and archaea) is much smaller and have differently structures (circular rather than linear). This might cause problems with how it gets inherited. Changing just the bases identities would not take care of these differences.

Some eukaryotic species have chemical modifications of nucleotides (DNA monomers) that can affect their function. The most common is methylation, which can effect gene expression. This would effect its function.

Interesting, learned something new, wasn't at all aware about the differences in DNA size!

That helpfully narrows down the range of possibilities.

Wonder if there's any animal DNA that's compatible enough that it could be reordered to become identical to human DNA. (potentially even functional)

Seems something that should be possible in the DNA of our nearest animal relatives. But obviously hasn't been tested. (that we know about)

It seems possible. It also seems it would be easier to build that DNA from scratch as opposed to a remodel. I know that ape DNA is 99% the same as human with only about 100 genes entirely different..

syfry said:

Interesting, learned something new, wasn't at all aware about the differences in DNA size!

That helpfully narrows down the range of possibilities.

Wonder if there's any animal DNA that's compatible enough that it could be reordered to become identical to human DNA. (potentially even functional)

Seems something that should be possible in the DNA of our nearest animal relatives. But obviously hasn't been tested. (that we know about)

I thought this would be a good addition to information you have already had.

If you click on the link scroll down to comparative genome sizes, some are very small like viruses or larger like bacteria which you would expect. However there some large genomes that do not necessarily come with more/large complexity.

Check the Marble lung fish, Amoeba and some of the plant species.

https://en.wikipedia.org/wiki/Genome

In addition to the different length, DNA of different organisms have different nucleotide ratios:

GC content is found to be variable with different organisms, the process of which is envisaged to be contributed to by variation in selection, mutational bias, and biased recombination-associated DNA repair.[19]

The average GC-content in human genomes ranges from 35% to 60% across 100-Kb fragments, with a mean of 41%.[20] The GC-content of Yeast (Saccharomyces cerevisiae) is 38%,[21] and that of another common model organism, thale cress (Arabidopsis thaliana), is 36%.[22] Because of the nature of the genetic code, it is virtually impossible for an organism to have a genome with a GC-content approaching either 0% or 100%. However, a species with an extremely low GC-content is Plasmodium falciparum (GC% = ~20%),[23] and it is usually common to refer to such examples as being AT-rich instead of GC-poor.[24]

Several mammalian species (e.g., shrew, microbat, tenrec, rabbit) have independently undergone a marked increase in the GC-content of their genes. These GC-content changes are correlated with species life-history traits (e.g., body mass or longevity) and genome size,[18] and might be linked to a molecular phenomenon called the GC-biased gene conversion.

Obviously, these ratios would not change by nucleotides reordering.

DNA is not just a simple strand of letters (aka nucleotides). @Hill nice post is correct.
I taught human genetics to med students a looong time ago and this kind of question was almost always asked.

There is some things that would answer your question as "Probably not - ", for ethical reasons and I believe partly due to misunderstanding. Let's look at aneuploidy - to get there we have to talk about ploidy.

Let's limit the discussion using just mammals or plants. The term for these organisms is "eucaryotic" which means they made of cells withe a nucleus, mitochondria, etc. This means we exclude bacteria.

We're going to use lowercase n to represent the number of sets of chromosomes

1n= haploid
2n= diploid
3n= triploid
.... keeps going

Examples: Using Eucaryotic plants and animals
Wheat has been bred into using more and more chromosome sets: 2n, 4n, and 6n
Modern wheat (Triticum ) is derived from ancestors It is: 6n 42 chromosomes. Hexaploid. Einkorn is diploid., 2n and is another kind of wheat.

Strawberries are bred from 2n -> 8n. 8n berries are much larger than 2n berries, 2n wheat grains are smaller and tougher chewing than 6n wheat

Ferns often have an n with hundreds of chromosomes in a set. Example:
One homosporous fern, Ophioglossum reticulatum, has more than 1400 chromosomes – the highest number for any plant, animal, or fungus. For comparison, humans have just 46 chromosomes, grouped into 23 pairs

But! We humans have a wrinkle:
Sex chromosomes.
In birds, females are the heterogametic sex, carrying one copy each of the Z and W sex chromosomes (ZW). Males are homogametic (ZZ).

For humans sex chromosomes are designated X and Y. Male cells are one X chromosome and one Y (XY) , females are XX.
Y chromosomes do not undergo crossing over.

Crossing over -- https://www.genome.gov/genetics-glossary/Crossing-Over

The human genome contains ~3 billion nucleotide pairs, even though most human cells contain 6 billion nucleotide pairs. DNA is a double helix: Each nucleotide on a strand of DNA has a complementary nucleotide on the other strand.

Aneuploidy is chromosome count is wrong or there is a damaged chromosome, from reordering base pairs or loss or gain base pairs.

Examples for aneuploid human babies:
Cri du Chat syndrome is pretty awful, for example. It is caused by a damaged chromosome #5.
https://www.ncbi.nlm.nih.gov/books/NBK482460/
Turners Syndrome is loss of or damage to an X chromosome. Loss of

The point I'm making is that there are vast complexities, and lots of ethical reasons not to do what you ask. Reordering will create aneuploidy -- As you specify "reorder" which is the same as damaging a chromosome.

Yes, should've emphasized better that I was asking more from curiosity, like could you take a human DNA, add and remove some letters until it matches some other animal's DNA, then swap in the altered yet identically lettered DNA into only one of the animal's cells, and it'll function completely like that animal's DNA without any noticeable difference, so if a biologist or geneticist were to examine the swapped cell, they wouldn't notice a difference.

But apparently things don't work like that in DNA, which answers my question anyway.

I was more trying to gauge if DNA is really exchangeable between different species or if they're too different. My original view was something like computer coding, where indeed we can probably rearrange the 1s and 0s of one app to perfectly recreate another app. (might have to duplicate some or delete some, but those are all you need... for example you wouldn't add any 3s or 4s, instead you'd be able to reuse what's there)

That was the heart of my question.

But if different computers were to have different sized 1s and 0s so they're incompatible from one system to another, then they wouldn't be compatible, so it's obvious that DNA letters in living things aren't anything like the 1s and 0s of coding in computers.

The takeaway from this post is that human DNA is a friggin mess. Evolution ate our simplistic lunch it seems.

There is a designation for "unused" DNA in a genome - introns. Introns do not do much. They are junk.
Our genome has only about 30K genes.
Turns out this is wrong.

It is somewhat messier:
https://byjus.com/biology/difference-between-exons-and-introns/

Example:
We share an awful lot of exons with chimpanzees. We share not so much of our ocean of "junk DNA" with chimps. So why are we so different from them?

And. So why do we have so much junk DNA ? It ain't junk. <- simple answer.
Want to get a headache? Try this as an explanation of exon functions: <- better answer and far more complicated:
https://pubmed.ncbi.nlm.nih.gov/26320575/

This explains why chimps and humans diverge so much while we share lots of genes. Blame it on junk.

Traits can be "controlled" on multiple, complex levels. Using what we thought was junk.

As you can see, this topic is way beyond the scope of simple strings of nucleotides (letters).
And so, this post has only a very limited usefulness.

Even if it's a friggin mess with a currently indecipherable jumble of junk, that's still exciting to realize because we happen to have a computer technology that shines at pattern recognition and at separating the signal from the noise.

The origins of some uncommon medical side effects might hide in the junk DNA, and sampling the junk DNA could potentially start to reveal patterns that identify in advance who might experience certain side effects before they even try a medicine.