最近科學(xué)家在兔子體內(nèi)發(fā)現(xiàn)了一種古老的類似HIV病毒的存在,。來自牛津大學(xué)的科學(xué)家發(fā)現(xiàn)這種特殊的慢病毒（lentivirus）屬于和HIV非常接近的病毒家族,，它們被保存在了歐洲兔的基因組內(nèi)。這一發(fā)現(xiàn)刊登于本周的《Proceedings of the National Academy of Sciences》上,，它將會(huì)改變科學(xué)家對(duì)于包括HIV在內(nèi)的多種病毒進(jìn)化的想法,。
這種病毒叫做RELIK（兔內(nèi)生慢病毒K），它是在兔子體內(nèi)發(fā)現(xiàn)的第一種慢病毒：在此之前慢病毒只在貓,、靈長類以及有蹄類中被發(fā)現(xiàn)過,。
RELIK同時(shí)也是已知的最古老的類病毒，它們已經(jīng)至少存在了7百萬年了,，而之前在貓類以及靈長類中發(fā)現(xiàn)的同類病毒只有1-2百萬年歷史,。但是RELIK在慢病毒家族中最重要的特征在于它是唯一可以從一代傳遞給另一代的慢病毒。
科學(xué)家是在分析歐洲兔的種群基因數(shù)據(jù)過程中發(fā)現(xiàn)這種獨(dú)特的病毒的,。他們利用了數(shù)學(xué)技術(shù)來分析基因組,、酶的結(jié)構(gòu)以及已知的慢病毒蛋白質(zhì)。利用以上這些技術(shù)得到的信息,，科學(xué)家才最終確定他們發(fā)現(xiàn)了一種只在兔子體內(nèi)存在的特殊慢病毒,。
此項(xiàng)研究的主要負(fù)責(zé)人，牛津大學(xué)的Aris Katzourakis博士表示：“這就好像從地下發(fā)掘出一種被認(rèn)為不存在的生物的化石,。之前人們認(rèn)為慢病毒不可能以內(nèi)生的方式存在,，這是由于它們的復(fù)制方式?jīng)Q定的。因此RELIK對(duì)于我們而言是一個(gè)驚喜,。” Katzourakis博士認(rèn)為,，在實(shí)驗(yàn)室復(fù)制這些病毒將幫助科學(xué)家了解HIV的起源。 譯自：physorg.com
部分英文原文：
Published online before print March 23, 2007
Proc. Natl. Acad. Sci. USA, 10.1073/pnas.0700471104
Evolution
Discovery and analysis of the first endogenous lentivirus
( phylogeny | retrovirus | ERV | rabbit )
Aris Katzourakis *, Michael Tristem , Oliver G. Pybus *, and Robert J. Gifford
*Department of Zoology, University of Oxford, South Parks Road, Oxford OX1 3PS, United Kingdom; Division of Biology, Imperial College London, Silwood Park, Ascot, Berkshire SL5 7PY, United Kingdom; and Division of Infectious Diseases, Stanford University, Stanford, CA 94305
Edited by John M. Coffin, Tufts University School of Medicine, Boston, MA, and approved February 13, 2007 (received for review January 17, 2007)
The lentiviruses are associated with a wide range of chronic diseases in mammals. These include immunodeficiencies (such as HIV/AIDS in humans), malignancies, and lymphatic and neurological disorders in primates, felids, and a variety of wild and domesticated ungulates. Evolutionary analyses of the genomic sequences of modern-day lentiviruses have suggested a relatively recent date for their emergence, but the failure to identify any endogenous, vertically transmitted examples has meant that their longer term evolutionary history and origin remain unknown. Here we report the discovery and characterization of retroviral sequences belonging to a new lentiviral subgroup from the European rabbit (Oryctolagus cuniculus). These viruses, the first endogenous examples described, are >7 million years old and thus provide the first evidence for an ancient origin of the lentiviruses. Despite being ancient, this subgroup contains many of the features found in present-day lentiviruses, such as the presence of tat and rev genes, thus also indicating an ancient origin for the complex regulation of lentivirus gene expression. Although the virus we describe is defective, reconstruction of an infectious progenitor could provide novel insights into lentivirus biology and host interactions.
