Different brain areas are genetically identical to one parent

 

Camus

@newstart_2024

·

12h

Mind-bender from Andrew Huberman: Your brain isn't a 50/50 genetic mix from mom and dad—entire regions could be 100% mom's or dad's DNA! Huberman spotlights Harvard's Catherine Dulac's work: Different brain areas are genetically identical to one parent, shown via marking studies and human genetics (e.g., Y-chromosome mutations appearing in some structures but not others). Example: Hypothalamic regions driving hunger/eating disorders (hyperphagia in obese kids) can carry mutations from one parent only—proving "territories" in the brain aren't uniform. "It's a myth that every cell is a 50-50 mix." So when someone says you "got that from your dad," it might literally be true for specific brain functions. Hypomorphs (reduced gene expression) add even more layers—human genetics is way messier than Mendelian basics. What's one trait you blame (or thank) on mom or dad—and does this science make you rethink it?

https://x.com/newstart_2024/status/2020969622095151462?s=20

Transcript from the X Video (Andrew Huberman on Modern Wisdom podcast with Chris Williamson)

Andrew Huberman: You're still gonna get — absolutely. You're still gonna get genomic DNA from mom, right? Those 23 chromosomes.

You're gonna get genomic DNA from mom and from dad. What's really a mind-bender (no pun intended) is there's a woman whose laboratory is at Harvard named Catherine Dulac, who is a luminary in the field of neuroscience.

She did some beautiful experiments showing that different brain areas are genetically identical to mom or to dad — even in you and me.

You have entire brain areas that are 100% the genes from dad... and 100% from mom in other areas.

It's a myth that every cell is a 50-50 mix of genes from mom (independent of the mitochondrial DNA piece — we're talking genomic DNA here).

They did marking studies where they color-code cells from mom or dad, but the more convincing evidence comes from Y-chromosome genes or disease mutations. You see cases where one brain area carries the mutation and another doesn't — even though it came through the dad on the Y chromosome. It should be everywhere, but it's not.

There are these little territories/domains that are essentially purely mom or purely dad.

And they correspond to entire brain structures that control things like hypothalamic function — there's a condition called hyperphagia (kids who can't stop eating and become severely obese) that shows up because specific hypothalamic regions are 100% from one parent.

Human genetics is way more complicated than basic Mendelian stuff. You get hypomorphs (reduced gene expression) layered on top.

So when people say "you clearly got that from your mom" or "that's all dad" — it might literally be true for specific brain functions, because entire regions can be 100% one parent.

Chris Williamson (interjecting toward the end): Yeah... much more like their dad in certain ways... much more like their mom in certain ways...

Huberman: Exactly — because we're never gonna know, but the brain is actually separated out into these parental territories.

(Video duration: ~2:21 — this is the full cleaned transcript from the clip's audio/subtitles with minor corrections for clarity; obvious OCR errors like "Duloc" → Dulac, "wide chromosome" → Y chromosome, etc. were fixed.)