Scandinavian population history revealed by ancient human genomes

I have Scandinavian ancestry, and it is something that has always been highly prominent in my family traditions. When my mom recently sent me this article, I was reminded of the interesting ancient past of Scandinavia and how little we know about the region prior to the Vikings. Northern Europe was one of the last places in the Old World to be populated by humans, and also one of the last places to adopt agriculture. Until recently, few studies had looked at the path of colonization of Scandinavia and who first settled there. This study, announced in Science Daily and completed by researchers at Max Planck, analyzed aDNA of 48 individuals dated from 7500 - 500 BC and found that there were likely two routes of migration into Scandinavia, and that agriculture was likely brought to the region by immigrants rather than by cultural diffusion and contact.

See the paper published in Nature Communications here.

-Kim Foecke

Ancient mammoth DNA could help save threatened elephants

Could elephant-mammoth hybrids roam the tundra? Researchers analyze the genes of several elephant species, and find genes from their extinct ancestors could help save them. An international team of scientists on Monday published the most detailed look yet at the genetic makeup of several different species of elephants, including extinct giants mammoths and mastodons.

Carly Johnson
https://www.cnet.com/news/woolly-mammoth-genes-study-traces-path-to-elephant-hybrid/

Traces of Taino

Reconstruction of a Taino village.

When I visited Puerto Rico for the first time several years ago, I was struck by the emphasis on ancient Taino culture, especially words, that I hadn't seen elsewhere in the Caribbean. The Taino people were thought to be extinct, yet many islanders have long insisted on a genealogical connection (correlating with a cultural one). aDNA extracted from the recent discovery of a Taino woman's tooth (found in a cave on Eleuthera in the Bahamas) proves that Taino do still exist. When Hannes Schroeder "compared the genomes of modern Puerto Ricans to the ancient Taino woman’s genome, he concluded that they descend in part from an indigenous population closely related to hers."

The full article in Ars Technica is a really interesting look at where some island populations come from, and where they have gone.

And here's another version, from Science.

-Courtney

Ancient DNA of Beaker Folk from central Europe

Photo: Dave Webb

Bell Beaker culture is a pottery industry from western and central Europe that emerged around 2750 BC and disappeared around 2000 BC. A Nature paper published last week explains how the Beaker people may have contributed to the ancestry of modern brits. Based on the ancient DNA from 155 individuals, the authors found that 90% of Britain's gene pool can be traced the Beaker folk that migrated to the area 4500 years ago. They also claim that the migration of Beaker folk into western and eastern Europe may have led to the rise in frequency of reduced eye and skin pigmentation observed during the Neolithic.

More more info, please see the original publication and the Guardian's article.

Angie

Whole Genome Sequencing Cheddar Man

In this article, published by The Scientist, a summary of the results of a whole genome
analysis of Cheddar Man is given. Researchers at London’s Natural History Museum and University College London analyzed a bone powder sample to identify phenotypes for a facial model construction. The article states that the analysis suggests the Cheddar Man was dark skinned, blue eyed, dark and curly haired, and lactose intolerant in adulthood. A documentary on the experimentation and a scientific paper are expected to be released in the near future.

The news article can be found here.

"Apples are from Kazakhstan" but horses aren’t

Przewalski's horses. Image from the Russian Geographical Society

It has been long argued that horses and horse domestication occurred in Kazakhstan about 5,000 years ago. However, a recent study looking at ancient horse DNA now suggest that theory is fails and modern horse evolved from an unidentified horse lineage. The study also showed that the last of the wild horses living today, the Przewalski's horse, are not actually wild horses, but domesticated horses that escape from their handlers--the Botai--thousands of years ago. The aDNA sampled also held another surprise, the ancient horse sampled was on its own branch separate from modern horses of today, indicating modern horses are not descendants of the ancient Botai horses that has been the hypothesis for many years. The researchers hope to clarify and identify where horses originate from by looking at ancient human DNA and their migration pattern at that time and in the region of Central Asia to find the horse population all modern day horses branched off from.

The read the Science Magazine press release click here. For the actual Science article click here.

Non-Potluck Post: Finding the RING in neurodevelopment

In a recent study published to the PNAS, Pierce and colleagues examines the consequences of a mutation to RING1, a protein coding gene that plays a role in  “epigenetic regulation of gene expression” during neurodevelopment, in a case study of a 13-year-old girl with who displays neurodevelopmental, psychiatric, and physical abnormalities (p. 1558).From genomic DNA comparison between the patient and her parents found the mutation was absent in both of the parents as well in a larger comparative sample of >120,000 exomes from a public database. Due to the lack of finding the a mutation of RING1 p.R95Q in both the parents and the database sample the authors identified mutation as a de novo mutation.

Once the authors identified the location of the mutation they compared the mutated RING1 p.R95Q to a wild type of RING1. RING1 in a non-abnormal in individual ubiquitylate histone H2A (e.g. it attaches ubiquitin which is a small protein to a targeted protein, in this case histone H2A). However, in the patient the researchers found RING1 p.R95Q failed to attach the protein together leading them to suggest the neurodevelopmental disorders the patient exhibited was caused by this mutation.

"RING 1 p.R95Q causes a defect in ubiquitylation of histone H2A specifically on nucleosomes. (A) In vitro nucleosome ubiquitylation assay of wild-type RING1 or RING1 p.R95Q heterodimers with BMI1 or PCGF1. All proteins and nucleosomes were expressed and purified, and protein concentrations in samples were matched using UV absorbance at 280 nm. Histone H2A was detected by immunoblotting. The RING1 p.R95Q mutant is deficient at ubiquitylating H2A in nucleosomes. (B) Structure of the RING2/BMI1 complex, showing BMI1 (tan), RING2 (green), and E2 (gold) bound to a nucleosome (gray) (PDB ID code 4R8P). The structure highlights the contact between the conserved positive arginine residue (blue spheres) and the nucleosome acidic patch (shown in red)." Pierce et al., 2017

The importance of this paper allowed for researchers to get “a glimpse into the role of RING1 in human neuronal development” and the impact it has on causing psychological disorders (p. 1562).

There was a lot more to this paper, however, I am not familiar enough with what was done to explain what they did in my own words.  

The paper can be read here.