
How many genes does it take to make a person? - Vigier
https://theconversation.com/how-many-genes-does-it-take-to-make-a-person-64284?utm_medium=email&utm_campaign=Latest%20from%20The%20Conversation%20for%20October%2021%202016&utm_content=Latest%20from%20The%20Conversation%20for%20October%2021%202016+CID_171026d4d60e023d8e933b20d398a1a8&utm_source=campaign_monitor_us&utm_term=How%20many%20genes%20does%20it%20take%20to%20make%20a%20person
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TheBiv
_This is one of those weird articles where having degrees in Biology,
Genetics, and CS converges so bear with me as I explain a lot of domain
specific terms_

Central dogma reminder: DNA -> RNA -> Protein.

In the scheme of a person, a gene (DNA) doesn't mean as much as protein
folding does. To give a programming example, DNA is the source code, RNA is
the compiler and proteins are the executed program.

A "person" is the executed program bc it's the end result. However tracing a
lineage back to the source code of DNA to figure out the smallest amount of
code required to create the program is often difficult (if not impossible).

Genes are the blueprint, how those genes are _transcribed_ into RNA and then
_translated_ into proteins matters FAR more than the amount of genes that it
would take to make a sustainable human.

So while I understand what this article is trying to get at, it's missing the
central dogma of molecular biology which is still the wild Wild West!

~~~
jonathansizz
You repeat a popular misinterpretation of the central dogma. The term was
coined by Crick^, and actually says that once the information in nucleic acid
goes into protein, you can't get it back out again.

So if you want to diagram it, it would be DNA/RNA --> Protein, where the arrow
represents information flow.

Note that (rather ironically!) it was actually Watson who popularized the
misinterpretation, in his college textbook. The reason I point this out is
that there are many known violations of the Watson version of the central
dogma, but none of the Crick version.

Also, I'd take issue with your claim that genes are like a blueprint. I'd say
they're more like a recipe, as stated in the article (and I think your comment
implies this anyway).

The larger point (that the article mostly ignores) centers around human
vanity: we're actually not really much more complicated than many other
species, especially our close relatives like the apes. Most of the differences
between us and them are developmental, and you don't need many genes to
produce such changes.

^ Crick 1956, 'Ideas on Protein Synthesis'.
[http://profiles.nlm.nih.gov/SC/B/B/F/T/_/scbbft.pdf](http://profiles.nlm.nih.gov/SC/B/B/F/T/_/scbbft.pdf)

~~~
TheBiv
The concept of messenger RNA (mRNA) is the source of your confusion.

As cited by their Nobel Prize, it is DNA -> RNA -> Protein. Please do not
confuse scientific facts with google searches you've done.

[http://www.nobelprize.org/educational/medicine/dna/](http://www.nobelprize.org/educational/medicine/dna/)

Please review this up to date article with how DNA turns into protein, in case
you are still needing more reference
[http://www.nature.com/scitable/topicpage/translation-dna-
to-...](http://www.nature.com/scitable/topicpage/translation-dna-to-mrna-to-
protein-393)

~~~
jonathansizz
I'm not confused. Your link shows how DNA is transcribed into RNA, which is
translated into protein.

That's not the central dogma; it's the misinterpretation of what the central
dogma states, which I pointed out in my above comment.

Please follow the link I gave in my earlier comment. I'll quote the pertinent
section here for you:

The Central Dogma: "Once information has got into protein it can't get out
again".

Here's a follow-up article by Crick, from 1970 (which he wrote in response to
repeated misinterpretations of what he'd originally stated):

[http://www.dna.caltech.edu/courses/cs191/paperscs191/CrickCe...](http://www.dna.caltech.edu/courses/cs191/paperscs191/CrickCentralDogma1970.pdf)

~~~
TheBiv
I understand, in general what you are saying, yet the links you're citing but
you have yet to talk about mRNA. All of your links are from 1960/1970
concerning scientific politics before we established scientific fact like we
have now.

I do not believe that you have reviewed my second link which takes you through
how DNA goes to RNA then to protein. Yes it's mRNA, but mRNA is RNA.

The inheritable material from DNA is in the nucleotides on the inside of the
double helix. Please review the Nature link to understand how DNA goes to RNA
and then protein.

~~~
jonathansizz
I really don't need a lesson on how transcription and translation work. I have
a PhD in genetics. I am of course not disputing that DNA is transcribed into
RNA and RNA is translated into protein.

In your original post, you state:

Central dogma reminder: DNA -> RNA -> Protein

and what I'm actually arguing with is your description of what the central
dogma is stating. Because it actually states

Nucleic Acid --> Protein

My criticism was a technical one regarding information flow, and I wasn't
trying to argue against the importance of developmental factors downstream of
genes to the production of complexity.

Sorry if I seem pedantic, but we have to be careful with our terminology,
because otherwise as soon as someone learns about reverse transcription they
write an article saying how the central dogma is dead.

~~~
TheBiv
Ahhhhhh man, I apologize bc we definitely got our wires crossed.

I believe that we both wanted the same thing (accurate information) and I was
willing to be simplistic in how the central dogma was presented bc it's
straightforward to grasp without talking about mRNA/tRNA/nucleic
acids/helicase/etc

I felt like you were initially distracting from the simplistic view that
everyone who hasn't studied genetics could understand.

Solid sidebar and I apologize for my tone and thank you for talking about your
side with me!!

Have a great day internet friend that loves genetics as well!!

------
nabla9
>Extrapolating the analysis beyond the human knockouts study leads to an
estimate that only 3,000 human genes are actually needed to build a healthy
human.

Genes are hyperparameters in the beginning of a dynamical process that creates
a person.

There is relatively straight forward path from DNA -> RNA -> primary structure
of proteins.

Complexity starts with more complex folding, secondary, tertiary and
quaternary structure and their conformations and changes (can be affected by
the state cell is in or environment)

Another source of complexity is the gene regulatory network (GRN). GRN can be
modeled as recurrent neural network or stochastic gene network. Genes are like
neurons and their activity level is their state. Gene activity is modified by
(noisy) activity or inactivity of other genes which have nonlinear inhibitory
and excitatory effects on others. The state of the cell is dynamic recurrent
process that can implement complex logic and respond to external and internal
stimuli. How much it can learn and adapt is interesting question.

Our microbiome, epigenetic factors, environment and the path person takes in
life can change how genes express themselves trough this process.

------
roflmyeggo
There is a simple counter-example that proves that this is the wrong question
to ask.

You cannot simply make a zygote with just the DNA from a sperm and an egg
together alone. Both parents pronuclei are required for epigenetic reasons. If
you try to do this, and the pronuclei are not present, then you will not make
any viable offspring.

This is just one example of how oversimplified the model taught by the book
is, though it is a useful one. The only thing that is certain is that we are
not anywhere near being able to claim to know how many genes it takes to make
a person.

------
spynxic
Still seems like everyone is making attempts to understand genetics from a
bottom-up approach. It doesn't make much sense to me to do so since there's no
framework to talk about what's being produced by the DNA (i.e. protein
functions)

It's similar to giving someone a random series of numbers and asking them to
continue it. The solution would be to try to understand the RNG instead of
blindly pattern matching.

~~~
toufka
You are correct. There are two different 'componentry' arguments here hiding
in the question.

The first is essentially, how many separable ingredients does it require to
make a person? This speaks nothing to how often, rarely, or combinatorially
those ingredients are used. The answer seems to be a fairly consistent order
of magnitude of ~10k unique protein components for a modern organism. With
some retaining a lot of old or duplicated code that's been commented out,
'just in case'.

The second (your point) seems even more valid. Many of those individual
components are themselves just mix-'n'-matched of separable protein domains.
And in fact the entire olfactory system generates thousands of separably
functional proteins from a single 'gene' by mixing and matching compatibly
functional protein domains. And on this count it's much more difficult to form
an answer for the required components in a person. Especially since the DNA
itself is not of much help when you're regexing for similar protein domains.

If a production car contains 1,000,000 components to assemble, coming from
50,000 unique part numbers, with each designed part being built by
extending/mixing-matching 2000 unique CAD files, using only 30 unique
alloys/materials, how many 'components' does it take to make the car?

The better question, exactly, is how many unique functions must the car
accomplish in order to be a car. There is still the issue of scale in that, is
'being attached' as valid of a function as 'cooling the engine' or 'moving
forward'. At least the counting of components can be done given today's
understanding of genetics.

------
coldcode
There are more genes in corn than in people. But in this case the count
doesn't matter, it's what you do with the genes.

------
thatwebdude
None, it's easier with them off (to make a person).

