Navigation Links
History of human cannibalism eats away at researchers

In a new study published by the journal Genome Research, a team of scientists reports that 'mad cow'-like diseases have not been a major force in human history, nor have been cannibalistic rituals that are known to be associated with disease transmission. Prof. Jaume Bertranpetit, a scientist at the Universitat Pompeu Fabra, and his colleagues used a fresh set of genetic data to show that balancing selection associated with cannibalism has not been a major selective driving force on the prion protein gene, as has recently been proposed. Their work also has important scientific implications for researchers using a specific class of DNA markers called SNPs (single nucleotide polymorphisms) to examine genetic associations with diseases or to evaluate historical patterns of human migration.

The prion protein gene (PRNP) encodes a protein that can abnormally fold and amass in brain tissues to cause fatal neurodegenerative diseases such as mad cow disease. These diseases are cumulatively known as transmissible spongiform encephalopathies (TSEs) and in humans, include CJD (Creutzfeldt-Jakob disease) and kuru. Kuru is confined to a human population in Papua-New Guinea and is transmitted by cannibalism at ritualistic mortuary feasts.

A high-profile study published nearly three years ago suggested that individuals who were heterozygous for a common polymorphism in the PRNP gene were relatively resistant to the disease. Over time, homozygotes who participated in the cannibalistic rituals purportedly diminished in numbers due to their increased susceptibility to kuru. This indicated that cannibalism conferred an effect of balancing selection on the PRNP gene throughout human history.

Bertranpetit and his colleagues sequenced 2,378 base pairs of the PRNP gene in 174 individuals; in addition, they genotyped two SNPs (or single nucleotide polymorphisms) from the PRNP gene in 1000 individuals from populations worldwide. They identified 28 different haplotypes ?or combinations of DNA variants ?in the PRNP gene and used this data to assess the ages of the mutations, to identify geographic patterns of variation, and to evaluate selective forces that have potentially influenced these patterns.

"In contrast to the previous study, which concluded that variation in the PRNP gene was strongly skewed toward intermediate frequency variants, our results showed that there was, in fact, a deficit of intermediate frequency variants," says Bertranpetit. "Our results are consistent with a complex history of episodic or fluctuating selection, including positive selection, purifying selection, and possibly even short periods of balancing selection."

On a more technical note, the study cautions researchers involved in SNP-based population genetics studies. The work is one of the first to empirically demonstrate how SNP ascertainment can introduce a strong bias in population genetics studies and severely affect the conclusions. Bertranpetit and his colleagues point out that at a time when a flood of ascertained SNP data is being generated, it is essential that SNP ascertainment be taken into consideration in data analyses.

The first author on the study is Dr. Marta Soldevila, who completed her Ph.D. at the Universitat Pompeu Fabra and performed a substantial part of the sequencing work at DeCODE Genetics (Reykjavik, Iceland).


'"/>

Source:Cold Spring Harbor Laboratory


Related biology news :

1. History-hunting geneticists can still follow familiar trail
2. Novel technology detects human DNA mutations
3. Current human embryonic stem cell lines contaminated UCSD/Salk team finds
4. UWs Rosetta software to unlock secrets of many human proteins
5. Genome-wide mouse study yields link to human leukemia
6. Found: Missing sequence of the human Y chromosome
7. Study finds more than one-third of human genome regulated by RNA
8. Molecular machine may lead to new drugs to combat human diseases
9. Sea skate experiment sheds light on human cell transport
10. Mouse brain tumors mimic those in human genetic disorder
11. Zebrafish may hold key to understanding human nerve cell development
Post Your Comments:
*Name:
*Comment:
*Email:


(Date:3/27/2017)... 2017  Catholic Health Services (CHS) has been ... (HIMSS) Analytics for achieving Stage 6 on the ... In addition, CHS previously earned a place in ... electronic medical record (EMR). "HIMSS Analytics ... EMR usage in an outpatient setting.  This recognition ...
(Date:3/23/2017)... Research and Markets has announced the addition ... - Industry Forecast to 2025" report to their offering. ... The Global Vehicle ... around 8.8% over the next decade to reach approximately $14.21 billion ... estimates and forecasts for all the given segments on global as ...
(Date:3/20/2017)... At this year,s CeBIT Chancellor Dr. Angela ... The Chancellor came to the DERMALOG stand together with the Japanese Prime ... partner country. At the largest German biometrics company the two government leaders ... iris recognition as well as DERMALOG´s multi-biometrics system.   ... ...
Breaking Biology News(10 mins):
(Date:4/27/2017)... ... 27, 2017 , ... Oncolinx, a spin-out of the Center ... truly taken their cancer research out of this world. On April 22, 2017, ... to the International Space Station’s (ISS) U.S. National Laboratory, managed by the Center ...
(Date:4/27/2017)... Luxembourg (PRWEB) , ... April 27, 2017 , ... Mitotech ... study in Leber’s Hereditary Optic Neuropathy (LHON) patients. LHON is a rare devastating genetic ... efficacy of SkQ1 eye drops in a group of 20 patients carrying 11778, 14484 ...
(Date:4/27/2017)... ... 2017 , ... Arrowhead Publishers is pleased to announce the ... San Diego, CA on September 27-28, 2017. Leaders from the pharmaceutical, biotech, device ... the treatment of various types of pain. There are also extended networking opportunities, ...
(Date:4/27/2017)... ... April 27, 2017 , ... Sierra Instruments announces ... capillary thermal mass flow technology provide exponentially more accurate mass flow data than ... of all industrial processes—such as those involving chemical reactions, combustion, respiration, pharmaceutical, and ...
Breaking Biology Technology: