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乙肝在千年前就诞生!

本帖最后由 癯鹤 于 2018-5-10 22:24 编辑

乙肝在千年前就诞生!2018-05-10 11:42:53 新浪看点 作者: 老肖的日常点滴作者: 我有话说
[size=+0]本周,丹麦哥本哈根大学的 Eske Willerslev 及同事在《自然》期刊上发表了两篇论文 137 ancient human genomes from across the Eurasian steppes 和 Ancient hepatitis B viruses from the Bronze Age to the Medieval period,其中一篇报道了 137 名约生活在 1,500-4,500 年前的古人类的基因组序列,另一篇分析了这 137 人的基因组和另外 167 名青铜时代人类的基因组,并在其中 25 人体内发现了乙型肝炎病毒(HBV)的证据。以上发现表明欧亚人类感染 HBV 的历史已有数千年之久。

[size=+0]古代样本的文化和地理呈现。
[size=+0]Damgaard et al.
[size=+0]作者测序了来自欧亚大草原的 137 名古人类的基因组,覆盖了长约 4000 年的一段时期 (欧亚大草原 是西起匈牙利,东至中国东北的一片长约 8000 公里的广阔区域)。此外,他们还研究了自我报告为拥有当今中亚、阿尔泰、西伯利亚和高加索血统的 502 名个体的基因组数据。这些发现帮助阐明了该区域的种群历史,表明青铜时代欧亚血统的牧民逐渐过渡至主要为东亚血统的骑兵。
[size=+0]在第二篇论文中,Willerslev 及其共同作者分析了 304 名来自欧亚中部及西部的古人类的 DNA 序列,这些人约生活在 200-7,000 年前。作者在 25 个人的体内发现了 HBV 感染证据,时间跨度近 4000 年。他们恢复了 12 个完整或部分的 HBV 基因组——包括目前已经灭绝的基因型,并把它们和当代人类及非人类灵长类动物的 HBV 基因组放在一起加以分析。结果发现某些古代 HBV 基因组的所在区域与其现今的分布区域不一致,而且至少有一种基因型现已灭绝。

[size=+0]样本和现代基因型的地理分布。
[size=+0]Mühlemann et al.
[size=+0]全球约有 2.57 亿人口长期感染 HBV,2015 年约有 88.7 万人死于相关并发症,但是该病毒的起源和演化一直不甚清楚。发现更古老的病毒序列或可以更加清楚地揭示 HBV 的真正起源和早期历史,并且帮助理解自然及文化变化对疾病负担与死亡率的影响。

人类感染乙肝史仅400年?古人类基因组揭示至少有数千年!
2018-05-10 20:07:04 新浪看点 作者: 澎湃新闻作者: 我有话说



[size=+0]现代医学对乙型肝炎病毒(hepatitis B virus, HBV)的认识始于1960年代,病毒发现者Baruch Samuel Blumberg和其他人共享了1976年诺贝尔生理学和医学奖。然而,全球仍有约2.57亿人口长期感染乙型肝炎病毒,2015年约有88.7万人死于相关的并发症,例如肝硬化、肝癌等疾病。
[size=+0]病毒的起源和演化是科学家在追求扼杀HBV途中的重要方向。北京时间5月10日,丹麦哥本哈根大学、剑桥大学进化遗传学家Eske Willerslev及其同事在《自然》(Nature)期刊上同时发表2篇论文,其中一篇即是他们在200-4500年前的欧亚古人类基因中发现了HBV存在的证据,表明人类感染HBV至少已有数千年历史。
[size=+0]“我们一直认为HBV是一种古老的人类病毒,但之前的证据可以证明的它们最悠久的历史也不过只有400年,但这次研究把历史推到了400年之前。”没有参与此项研究的澳大利亚多尔蒂研究所维多利亚传染病参考实验室高级医学科学家Margaret Littlejohn如此点评,“这无疑是该领域的一次飞跃。”

[size=+0]样本和现代基因型的地理分布。
[size=+0]“废弃”DNA中隐藏线索
[size=+0]该研究始于Eske Willerslev及其同事的一项调查,他们最初想要阐明欧亚大草原上的人类历史。欧亚大草原是西起匈牙利,东至中国东北的一片长约8000公里的广阔区域。
[size=+0]研究团队采用鸟枪法测序。“我们发现得到的绝大部分DNA实际上并非是人类的。”Willerslev表示,“一开始,这些并不是我们重视的东西,它就相当于是我们研究中的某种副产物,但后来我们开始调查这些废弃产物或许是某种病原体。”
[size=+0]研究团队随后意识到这些“废弃”DNA或许能对HBV的起源提供新线索。他们从本次调查研究基因组中采集了137例,及另外167名青铜器时代人类的基因组(Willerslev在2015年发表在《自然》上的成果),来着重研究HBV起源。
[size=+0]Willerslev及其同事分析了上述304名来自欧亚中部及西部的古人类的DNA序列,这些人约生活在200-7000年前。最后,研究团队在25个人的体内发现了HBV感染证据,时间跨度近4000年(生活在800-4500年前),其中一些骨头来源于蒙古国一处乱葬岗中的一名战士。
[size=+0]随后,他们恢复了12个完整或部分的HBV基因组,其中一种基因型目前已经灭绝。
[size=+0]研究团队还把它们和当代人类及非人类灵长类动物的HBV基因组放在一起加以分析。结果发现,其中有3个古老HBV基因组和现代的大猩猩和黑猩猩的HBV基因组最接近。
[size=+0]HBV起源仍旧是个迷
[size=+0]尽管Willerslev及其同事此番将人类HBV的历史往前推进了数千年,但真正起源仍成迷。
[size=+0]Willerslev测序的HBV基因组提供了病毒有重组的证据,以及有一些目前已经灭绝,暗示人类HBV至少存在于4500年前。然而,病毒需要时间来经受这样的进化改变,所有的新发现都指向:HBV起源于更早时候。
[size=+0]维多利亚传染病参考实验室另一名高级医学科学家Lilly Yuen表示,“当科学家试图推断HBV的历史时,最早的数据一般都是倾向于几百年或者几年前以前”。但其他的一些研究已经在古老的鸟类基因组中发现鸟类HBV版本,这表明HBV可能起源于数百万年之前。
[size=+0]实际上,就在5月7日,德国马克斯-普朗克研究所(MPI)进化遗传学家Johannes Krause及其同事在预印本在线期刊 BioRxiv发表了一项研究成果,他们在人类牙齿样本中发现了3个古老的HBV基因组,其中一个有近7000年历史。
[size=+0]Krause对Willerslev等人的最新成果点评,“我们都很兴奋,我们可以将HBV的历史拉回到如此久远的时代。”但Krause同时表示,根据他们自己的工作及Willerslev 团队的研究成果,HBV的历史仍旧是个迷,“它可能会古老很多。”

[size=+0]论文的第一作者、剑桥大学研究生Barbara Mühlemann提到,他们对人类HBV病毒历史研究的下一步将更深入地研究它们的变异情况,以此判断病毒未来可能发生的变化。


Strain of hepatitis B found on a 4,500-year-old skeleton is the oldest human virus ever to be discovered
Strain extracted from a skeleton could provide oldest ever evidence of the virus
  • Scientists say the 'truly remarkable' study was on par with finding the first fossils
  • Study said that it was not previously know that virus could become extinct

ByColin Fernandez Science Correspondent For The Daily Mail
Published: 18:01 BST, 9 May 2018 | Updated: 08:29 BST, 10 May 2018
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The oldest human virus has been discovered in a 4,500-year old skeleton.
Scientists say the extinct strain of hepatitis B – the potentially lethal liver disease that affects millions – has ‘transformed’ their understanding of the virus.
British scientists said the ‘truly remarkable’ discovery was on a par with finding the first fossils.
Previously the oldest detected human viruses dated back around 450 years.

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Scientists took DNA from the skeletons to search for evidence of the Hepatitis B virus

The hepatitis B virus has many mutations that no longer exist – and the information could help us prepare for dangerous new strains, scientists said.
The discovery was made by carrying out DNA sampling on a Bronze Age skeleton in Osterhofen, Germany, as part of a wider study of 300 skeletons from central and western Eurasia, which are between 200 and 7,000 years old.
The hepatitis B skeleton belonged to the ‘Bell Beaker’ culture, so called because of the bell-shaped pottery cups left behind.

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The study, published in the journal Nature, said it was not previously known that viruses could become extinct



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The hepatitis B virus has many mutations that no longer exist – and the information could help us prepare for dangerous new strains, scientists said

The study, published in the journal Nature, said it was not previously known that viruses could become extinct.
Joint lead author Barbara Muhlemann, a Cambridge University PhD student, said: ‘People have tried to unravel the history of HBV for decades.
'This study transforms our understanding of the virus.’



Read more: http://www.dailymail.co.uk/news/article-5710373/Oldest-human-virus-discovered-Bronze-Age-bones.html#ixzz5F6num6Kq
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红松鼠让亚洲又摆脱了一项指责:

Leprosy started in Europe NOT Asia and red squirrels were responsible for bringing it to Britain more than 1,000 years ago, DNA study suggests
  • Red squirrels are responsible for bringing the leprosy bacteria to British shores
  • Strand of the disease found in the rodents today was found in ancient skeletons
  • Red squirrels were prized for their meat and fur by people in ancient Britain
  • Leprosy causes severe deformities and affected millions in the Middle Ages
By Tim Collins For Mailonline and Press Association
Published: 19:01 BST, 10 May 2018 | Updated: 23:09 BST, 10 May 2018



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Leprosy had its beginnings in Europe rather than Asia and was brought to Britain more than 1,000 years ago - thanks to the trade in red squirrels.
That's the finding of research which looked at DNA to reveal the strains of the disease circulating in Medieval Europe, in the largest study of its kind.
It revealed more strains of the devastating disease than expected in medieval Europe, calling into question the historical assumption that it began if the East.
Genetic material taken from a fifth-century victim of the disease in Essex also contained the same strain of leprosy bacteria still carried by red squirrels today.
Experts say this suggests the rodents, then prized for their fur and meat, played a crucial role in the spread of the infection.
Scroll down for video

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Leprosy had its beginnings in Europe rather than Asia and was brought to Britain more than 1,000 years ago. That's the finding of research which looked at DNA from human remains (pictured) to reveal the strains of the disease circulating in Medieval Europe

An international team of team, including scientists from the Max Planck Institute for the Science of Human History (MPISHH), took samples of leprosy DNA.
These were taken from the remains of 90 European people, who lived between 400 and 1,400 AD, that were selected due to skeletal deformations characteristic of the disease.
Among the selected remains was a skeleton from Great Chesterford, Essex, dated to between 415 and 545 AD.
It was this leprosy genome, the oldest yet constructed, that contained the red squirrel clue.
Researchers used the data they collected to reconstruct 10 new genomes, or complete genetic codes, of the bug that causes leprosy - known as Mycobacterium leprae.


Previous research on the bacterium suggested that it clusters into several strains, only two of which were present in Medieval Europe.
The diversity of the newly uncovered strains suggests the disease may be at least a few thousand years old, experts say.
'We found much more genetic diversity in ancient Europe than expected,' said Professor Johannes Krause, senior author of the study and a director at MPISHH.
'Additionally, we found that all known strains of leprosy are present in Medieval Europe, suggesting that leprosy may already have been widespread throughout Asia and Europe in antiquity or that it might have originated in western Eurasia.'

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From the bone fragments, experts reconstructed 10 new genomes of medieval Mycobacterium leprae, the bug that causes leprosy. The 90 individuals that were lepers (pictured) were found to have the same strand of the bacteria as found in red squirrels


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The new research suggests that leprosy may have originated in western Europe or Asia. The medieval genomes included strains now found in Asia, Africa and the Americas. Pictured bones found in Essex that once belonged to a leper were used as part of the research


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Leprosy causes severe bone deformities (pictured) and was prevalent in Europe until the 16th century and is still endemic in many countries, with more than 200,000 cases reported each year

WHAT IS LEPROSY? Leprosy is a long-term infectious disease which can result in the inflammation of the nerves, respiratory tract, skin, and eyes.
The disease is initially symptom-less and can remain undetected for five to 20 years.
Typically found among those living in poverty, leprosy was common during the Middle Ages and then again in nineteenth century but it can still be found in developed and developing countries today.
In 2012, the number of chronic cases of leprosy was 189,000, down from some 5.2 million in the 1980s, with India accounting for more than half of all cases.


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Leprosy was prevalent in Europe until the 16th century and is still endemic in many countries, with more than 200,000 cases reported each year.
The medieval genomes included strains now found in Asia, Africa and the Americas.
Lead researcher Dr Verena Schuenemann, from the University of Zurich, Switzerland, added: 'The dynamics of M. leprae transmission throughout human history are not fully resolved.
'Characterisation and geographic association of the most ancestral strains are crucial for deciphering leprosy’s exact origin.
'While we have some written records of leprosy cases that predate the Common Era, none of these have yet been confirmed on a molecular level.'
The full findings of the study were published in the journal PLOS Pathogens.

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Genetic material taken from a fifth-century victim of the disease in Essex also contained the same strain of leprosy bacteria still carried by red squirrels today. Experts say this suggests the rodents (pictured) played a crucial role in the spread of the infection




Read more: http://www.dailymail.co.uk/sciencetech/article-5715105/Red-squirrels-carried-leprosy-UK-study-shows.html#ixzz5F91CwFww
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