This is the first in a series of technical posts I hope to put together over the coming weeks about the process of creating Stranger Visions. Starting from the lab end I will describe in detail how I create these portraits from DNA.
The first step of course is extracting DNA from a sample, that can be done with a kit readily obtainable from Qiagen, the “DNA Investigator Kit”.
After I extract the DNA* I do a test PCR for a specific alu insertion using a primer (full kit is also available) from Carolina. This gives me an idea of whether I successfully extracted chromosomal DNA or not. If the results look bad on this there is probably no reason to go further with this sample.
If all these results look good I continue to look at 3 SNPs associated with particular traits and 1 region on the y chromsome:
rs12913832 – for eye color
SRY gene – present on Y chromosome, I use to indicate gender
rs9939609 – as one of many indicators of obesity
rs4648379 – preliminary research, correlated with the size of the nose
I have been using a free tool on IDT for designing primers to target these regions using PCR. If the result of the reactions looks good in a gel I send them for sequencing.
So those are SNPs I have had success so far analyzing in the lab myself, but there are a whole lot more clues I have on a “master list”, the things I can find out from a 23andme profile for example. In addition to SNPs related to specific traits this includes Y chromosome haplogroup information from males to get an idea of paternal ancestry, as well as Ancestry Informative Markers, specific SNPs that are correlated with population studies giving an overall picture of ancestry beyond the direct maternal and paternal lineage. I am pasting my master list here below (excluding the ancestry info I just mentioned and linked to above as that would increase the list a thousand fold). Also, here is a link to appearance related SNPs on snpedia.
*I have recently discovered that whole genome amplification can also be performed after the extraction step and isn’t as expensive as I previously though – I will likely pursue this in future experiments.
|rs1426654||AA||light skinned european|
|rs17646946||GG||curlier hair in europeans|
|rs12896399||TT||blue eyes vs green if not brown – prelim research|
|rs1426654||AA||euro ancestry – light skinned|
|rs1667394||CC||decreased odds blond hair|
|rs1805007||TT||higher odds red hair|
|rs1851665||AA||greater chance of obesity|
|rs3827760||AG||thinner hair (asian)|
|rs1393350||AA||blue eyes rather than green IF non-brown – preliminary research|
|rs1533995||AA||more pronounced crypts|
|GG||less pronounced crypts|
|AC,CC||less iris furrows|
|rs12896399||GG||more pronounced pigementation rings|
|TT||absent pigmentation rings|
|CT||slightly higher odds red hair|
|TT||increased odds brown hair|
|rs1042602||AA||absence of freckles|
|CT;TT lighter skin|
|rs1800414||C||each c -> 1.3 melanin unit lighter skin in east asians|
|rs16891982||GG||european light skinned|
|preliminary facial research||source|
|rs4648379||C/T||edge of nostril -> tip of lower nose|
|rs974448||C/T||mid eye to top of nose|
|rs17447439||A/G||distance between eyes|
|rs6555969||C/T||distance between cheekbone and nose, ALSO distance between eye and top nose|
|rs805722||C/T||distance between eye and top of nose|
|Eye and Skin color||source|