This article is from the source 'guardian' and was first published or seen on . It last changed over 40 days ago and won't be checked again for changes.

You can find the current article at its original source at http://www.theguardian.com/science/2014/jan/28/plague-victims-shed-light-disease-origins

The article has changed 5 times. There is an RSS feed of changes available.

Version 0 Version 1
1,500-year-old plague victims shed light on disease origins 1,500-year-old plague victims shed light on disease origins
(about 14 hours later)
Scientists have previously analysed DNA samples taken from plague victims to determine that the Plague of Justinian was likely caused by Yersinia pestis, the bacterium also responsible for the Black Death.Scientists have previously analysed DNA samples taken from plague victims to determine that the Plague of Justinian was likely caused by Yersinia pestis, the bacterium also responsible for the Black Death.
They then screened the samples for Y pestis DNA and sequenced the genomes of the two strains they found.
"This is the first complete genome from one of the most significant disease events in human history," he said."This is the first complete genome from one of the most significant disease events in human history," he said.
Associate professor Jeremy Austin, from the Australian Centre for Ancient DNA said the study was an important insight into the evolution of an infectious disease.  Associate professor Jeremy Austin, from the Australian Centre for Ancient DNA said the study was an important insight into the evolution of an infectious disease.
"It certainly tells us that these catastrophic diseases aren't things that evolve once, and then lurk around waiting for an opportunity to reappear – they actually evolve multiple times from different ancestors," he said.   "It certainly tells us that these catastrophic diseases aren't things that evolve once, and then lurk around waiting for an opportunity to reappear – they actually evolve multiple times from different ancestors," he said.
"Which makes it very much harder to predict when they're going to happen next, and how they evolve and therefore how you might prevent them happening.""Which makes it very much harder to predict when they're going to happen next, and how they evolve and therefore how you might prevent them happening."
Allen Cheng, associate professor at Monash University's Infectious Diseases Epidemiology unit, said the Lancet study was "fascinating".Allen Cheng, associate professor at Monash University's Infectious Diseases Epidemiology unit, said the Lancet study was "fascinating".
"There's a whole field of paleo-phylogeny, going back into history and trying to work out the origin of diseases."There's a whole field of paleo-phylogeny, going back into history and trying to work out the origin of diseases.
Holmes said one of their objectives was to determine why the Justinianic plague was so severe. Holmes said one of the objectives of the researchers from the McMaster, Northern Arizona and Sydney universities was to determine why the Justinianic plague was so severe.
"Was there something about the genome of these ancient pathogens that made them especially virulent, or was it the way that people lived in the past, conditions were not so good, general health wasn't as good, that made them die in higher numbers?""Was there something about the genome of these ancient pathogens that made them especially virulent, or was it the way that people lived in the past, conditions were not so good, general health wasn't as good, that made them die in higher numbers?"
He said the paper was indicative of technical advances that have revolutionised the study of ancient DNA.He said the paper was indicative of technical advances that have revolutionised the study of ancient DNA.
"Modern technology has made [studying] ancient DNA a much stronger science," he said.    "Modern technology has made [studying] ancient DNA a much stronger science," he said.
DNA is prone to degradation over time into small fragments, which was an issue for older sequencing techniques that relied on getting comparatively long, coherent strands of DNA. However, "next gen" sequencing is designed to use many small pieces of DNA, and so has made sequencing older DNA much easier.DNA is prone to degradation over time into small fragments, which was an issue for older sequencing techniques that relied on getting comparatively long, coherent strands of DNA. However, "next gen" sequencing is designed to use many small pieces of DNA, and so has made sequencing older DNA much easier.
"We can amplify huge numbers of these small fragments, and basically glue them together," Holmes said.   "We can amplify huge numbers of these small fragments, and basically glue them together," Holmes said.
Austin agreed, saying new techniques had resulted in boom of genome sequences from ancient animals, humans, and other organisms.Austin agreed, saying new techniques had resulted in boom of genome sequences from ancient animals, humans, and other organisms.
"Ten years ago, everyone was saying we're not going to be able to sequence genomes of extinct anything, whether they be humans, animals, plants or other things lurking around in the environment," he said."Ten years ago, everyone was saying we're not going to be able to sequence genomes of extinct anything, whether they be humans, animals, plants or other things lurking around in the environment," he said.
"We're certain using these techniques to get access to information that even five years ago we never thought was possible.""We're certain using these techniques to get access to information that even five years ago we never thought was possible."
• This article was amended on 28 January 2013 to make clear that the work was done by an international team of researchers and was based at the Ancient DNA Centre of McMaster University in Ontario, Canada.