Genotyping and Slavery

Genotyping and sequencing are two ways of reading information from DNA, but the technology and the results you get are very different. Think of your DNA as a book, genotyping would be like choosing a specific word from a single page. Once you choose a word, you are limited to gaining the information that the one word on that one page can give you. If you ever want to learn about a word on a different page that you didn't choose to have genotyped, you would need to be genotyped again. By contrast, sequencing is like reading whole sentences. We get more information and more context, all 22,000 genes and then some. So from one small sample, we can get insight on family history, health, and even fitness and nutrition. 

 

The famously known 23andme biotechnology company, specializing in obtaining insight on personal genetic information through genotyping, has turned their attention to the African American genome and if it holds any information on slave practices. An article (1) explains that they obtained genetic samples from consenting customers who lived in African and South American countries bordering the Atlantic Ocean, specifically focusing on the West Coast of Africa, and the eastern coastline of North, Central and South America. With these samples, they compare the IBD (identity by descent) distinguished by the chromosomal similarities in Americans of African descent and Africans. With each passing generation, these IBD sections get split, but with technology they can calculate who the most recent common ancestor is. What they found through this was that enslaved women contributed a lot more to the gene pool of modern day African-Americans than enslaved women, which suggests that there was a history of sexual exploitation of enslaved women. The data collected shows that in some regions “roughly 15 African women had children for each African man”, even though men were the majority of the population. The ratio isn’t as high in other regions with a high slave population, but it is still skewed heavily toward women having more children.

 

As 23andme uses genotyping (2), we can only read into a small part of the story regarding slavery and its lingering effects. If sequencing the entire human genome is made available at an affordable cost, we can reveal more information on what occured back then and furthermore how epigenetics can still affect African Americans today.

            

 

Posted by: Timinte Abraham (1)                       

 

References

1. https://www.the-scientist.com/news-opinion/african-american-genomes-yield-insight-into-slavery-practices-67766