Korean Mummy Reveals Hepatitis B Genetic Clues

liver411

         
Details Category: HBV Basic Science         Published on Wednesday, 30 May 2012 00:00         Written by Press Release

Genetic analysis of a liver sample from a mummified child found in Korea has revealed a distinct ancient form of a hepatitis B virus C2 genotype now common in Southeast Asia, researchers reported in the May 21, 2012, advance online edition of Hepatology.

Below is an edited excerpt from a press release issued by the Hebrew University of Jerusalem describing the research and its findings.

16th-Century Korean Mummy Provides Clue to Hepatitis B Virus Genetic Code

May 29, 2012 -- The discovery of a mummified Korean child with relatively preserved organs enabled an Israeli-South Korean scientific team to conduct a genetic analysis on a liver biopsy which revealed a unique hepatitis B virus (HBV) genotype C2 sequence common in Southeast Asia.

Additional analysis of the ancient HBV genomes may be used as a model to study the evolution of chronic hepatitis B and help understand the spread of the virus, possibly from Africa to East-Asia. It also may shed further light on the migratory pathway of hepatitis B in the Far East from China and Japan to Korea, as well as to other regions in Asia and Australia where it is a major cause of cirrhosis and liver cancer.

The reconstruction of the ancient hepatitis B virus genetic code is the oldest full viral genome described in the scientific literature to date. It was reported in the May 21 edition of the scientific journal Hepathology by a research team from the Hebrew University of Jerusalem’s Koret School of Veterinary Medicine, the Robert H. Smith Faculty of Agriculture, Food and Environment; the Hebrew University’s Faculty of Medicine, the Hadassah Medical Center’s Liver Unit; Dankook University, and Seoul National University in South Korea.

Carbon 14 tests of the clothing of the mummy suggests that the boy lived around the 16th century during the Korean Joseon Dynasty. The viral DNA sequences recovered from the liver biopsy enabled the scientists to map the entire ancient hepatitis B viral genome.

Using modern-day molecular genetic techniques, the researchers compared the ancient DNA sequences with contemporary viral genomes disclosing distinct differences. The changes in the genetic code are believed to result from spontaneous mutations and possibly environmental pressures during the virus evolutionary process. Based on the observed mutations rates over time, the analysis suggests that the reconstructed mummy’s hepatitis B virus DNA had its origin between 3,000 to 100,000 years ago.

The hepatitis B virus is transmitted through the contact with infected body fluids, i.e. from carrier mothers to their babies, through sexual contact, and intravenous drug abuse. According to the World Health Organization, there are over 400 million carriers of the virus worldwide, predominantly in Africa, China and South Korea, where up to 15 percent of the population are carriers of the virus. In recent years, universal immunization of newborns against hepatitis B in Israel and in South Korea has lead to a massive decline in the incidence of infection.

The findings are the result of a collaborative effort between Dr. Gila Kahila Bar-Gal of the Hebrew University of Jerusalem’s Koret School of Veterinary Medicine; Prof. Daniel Shouval of the Hadassah Medical Center’s Liver Unit and Hebrew University; Dr. Myeung Ju Kim of Dankook University, Seok Ju Seon Memorial Museum; Dr. Dong Hoon Shin of Seoul National University, College of Medicine; Prof Mark Spigelman of the Hebrew University’s Dept. of Parasitology and Dr. Paul R. Grant of University College of London, Dept. of Virology.

5/18/12

Reference

GK Bar-Gal, MJ Kim, A Klein, D Shouval, et al. Tracing hepatitis B virus to the 16th century in a Korean mummy. Hepatology. May 21, 2012 (Epub ahead of print).

Other Source

Hebrew University of Jerusalem. 16th-Century Korean Mummy Provides Clue to Hepatitis B Virus Genetic Code. Press release. May 29, 2012.

MP4

3,000 to 100,000 years ago

MP4

http://www.guokr.com/article/207714/
16世纪韩国木乃伊暗藏乙肝病毒秘密
solahaloha 2012-06-01 22:29:44
科学家从16世纪朝鲜小男孩的木乃伊中重建了古老的乙肝病毒基因组，分析结果可以用来研究病毒演化历程和传播史。

来自韩国和以色列的科学家们在一具韩国儿童木乃伊中发现了一种独特的乙肝病毒（HBV）C2基因亚型。此类基因型在东南亚地区非常普遍。早在2007年，研究人员就从这具木乃伊保存尚好的肝脏中发现了乙肝病毒。而这一次，遗传密码的破解更为完全、彻底。对木乃伊衣物进行的碳14检测揭示这个小男孩生活在16世纪的朝鲜王朝（Korean Joseon Dynasty）。在肝脏活体切片中发现的DNA序列让科学家们绘制出了完整的古老HBV基因组图，这是迄今为止文献记录中人们所重建的最古老的完整病毒基因组。 研究 结果发表在5月21日的《肝病学》（Hepathology）上。

慢性乙型肝炎是肝硬化和肝癌的主要诱因。对这一古代HBV基因组的深入分析可用来研究病毒演化历程和传播史（很有可能最初由非洲传入东亚）；也有可能进一步阐明病毒又是如何从远东（中国、日本、韩国）迁徙至亚洲其他地区以及澳大利亚的。

研究人员利用现代分子遗传技术比较了古代HBV与现代HBV的DNA序列，二者显示出明显差异。遗传密码的改变可能是病毒在进化过程中因环境压力而产生的自发变异。根据基因的普遍变异速率分析，木乃伊中的HBV基因可上溯至3000年甚至10万年前。

HBV是通过与感染个体的体液接触而传播的。如母婴传播、性接触传播和静脉注射毒品。根据世界卫生组织（WHO）的统计，全球有4亿以上的HBV携带者，绝大多数集中在非洲、中国和韩国。这些地区人口的病毒携带率达到了将近15%。不过近些年来，亚洲地区普遍采取的新生儿免疫措施已经使乙肝感染率大幅下降。

本文编译自: ScienceDaily, 16th-Century Korean Mummy Provides Clue to Hepatitis B Virus Genetic Code
图片: Seoul National Univesity