TED Conversations

Closing Statement from Emo Bear

I got an interesting email from this conversation:

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Genes related to brain growth

Hello,
I'm contacting you in relation to the conversation thread you started about the talk "Building a dinosaur from a chicken".

Genes indirectly responsible for brain growth have been found in the human genome, namely the Highly Conserved Deletion (hConDel) number 332. This sequence acts on the gene GADD45G which normally inhibit neuron production. However the human variant of hConDel332 is completely absent, meaning that it doesn't activate the gene GADD45G and so neuron production isn't heavily regulated *1.

But it won't be enough to confer proto-human intelligence to animals, as we'll also need at least :
- the gene LAMC3, regulating the folding of the cerebral cortex during embryo-genesis*2.
- the FOXp2 gene, for the development of the vocal cords and cerebral areas dedicated to language
- the HACNS1 enhancer, regulating the formation of the wrists, ankles, hips, throat and especially the thumb *3.

*1 McLean et al. ”Human-specific loss of regulatory DNA and the evolution of human-specific traits”
Nature,471:216-219, 2011
*2 Barak T. et al. ”Recessive LAMC3 mutations cause malformations of occipital cortical development
Nature Genetics, 43:590-594, 2011
*3 Prabhakar et al. ”Human-Specific Gain of Function in a Developmental Enhancer”
Science, 321(5894):1346-1350, 2008

Cordially,
Pr. Théodose