Kandiru t1_ishbuwl wrote
Reply to comment by promonk in When it's said 99.9% of human DNA is the same in all humans, is this referring to only coding DNA or both coding and non-coding DNA combined? by PeanutSalsa
It's no one person's. It's a mishmash of several different high quality genomes, and then over time it's been changed to have the more common variants as the reference rather than the reference being a rare mutation for some genes.
promonk t1_ishdkr1 wrote
When you say "more common variants," common in what way?
I'm fascinated by the idea of a "reference human."
Kandiru t1_ishg2ww wrote
Say a certain position is a A for 90% of people, but a C for 10%. The A variant is more common than the C.
So when the reference had previously had a C there, in a later version it's often been changed to the most frequent base.
promonk t1_ishu3eb wrote
I get that. What I'm curious about is sampling. 90% of which population? Is it 90 of some college-age kids being paid a hundred bucks for a cheek swab? Or is it drawn from a broad swathe of demographics and locations?
emfts t1_isiaa4s wrote
The first human reference genome (from the human genome project) was a group of people from all over, random volunteers.
You can read all about it here:
https://www.genome.gov/12513430/2004-release-ihgsc-describes-finished-human-sequence
Kandiru t1_isimfb1 wrote
The 1000 genome project used populations around the world
http://ftp.1000genomes.ebi.ac.uk/vol1/ftp/README_populations.md
Has a list of the ones used.
[deleted] t1_ishhjrb wrote
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[deleted] t1_isiu3kr wrote
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tsunamisurfer t1_ishsh54 wrote
Originally though, the reference genome was that of the first sequenced human genome, which I believe belonged to J Craig Venter.
Kandiru t1_isim3ny wrote
Actually there were two competing approaches at the beginning. Venter did sequence himself with shotgun sequencing, while the high fidelity BAC sequencing with Sanger sequencing was done on a range of different individuals spanning the genome.
So the first version of the reference was a mixture of them all.
Angdrambor t1_isjtnw2 wrote
What makes a genome "High quality"?
[deleted] t1_isjukzq wrote
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danby t1_islg7bo wrote
Though I only spent a handful of years in genome sequencing I suspect what is probably meant here is that the sequence was based on several genomes where they were able to prepare high quality genomic libraries for those genomes.
Angdrambor t1_ismpsxm wrote
What makes a genomic library high or low quality? Few errors? Faithful representation of the original?
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