只有了解致命病毒的進化過程,，我們才能有效地降低它們的傷害,。一些常年生活在動物體內的病毒片段讓我們看到,，病毒們是怎樣巧妙潛入了昆蟲和其它動物的基因組里，隨著動物們一起進化的,。該研究發(fā)表在近期的《公共科學圖書館—遺傳學》（PLoS Genetics）上,。
來自洛克菲勒大學(Rockefeller University)的R.Gifford和牛津大學(Oxford University)的A.Katzourakis使用了先進的遺傳學技術，分析昆蟲,、哺乳動物和鳥類的DNA數據庫,，尋找病毒基因組的片段，這些片段叫做內生病毒元件（EVEs）,。兩位科學家在其中發(fā)現了十個科的代表病毒,，包括B型肝炎病毒、埃博拉,、狂犬病,、登革熱等多種病毒都整合在動物基因組里。
Gifford認為,，他們找到了某些病毒類群的前身,。自1970年以來，科學家們一直致力于尋找逆轉錄病毒在動物基因組中的證據,，很少有人關注那些非逆轉錄病毒中的內生病毒元件是怎樣演化,、怎樣插入寄主的細胞核DNA的,。
研究者們收集到的大部分病毒片段都已經不具備功能，成為俗稱的“垃圾DNA”,。然而他們發(fā)現,，在它們進化史中的某些時間段，這些病毒片段被寄主啟用過,，可能是用作免疫防止感染相關病毒,。研究者們特別強調，在昆蟲基因組找到的內生病毒元件能幫助我們探索病毒間的進化聯系,，提供給我們寄主以及遠古生態(tài)環(huán)境的信息,。（生物谷Bioon.com）
生物谷推薦原文出處：
PLoS Genetics doi:10.1371/journal.pgen.1001191
Endogenous Viral Elements in Animal Genomes
Aris Katzourakis1*, Robert J. Gifford2*
1 Department of Zoology, University of Oxford, Oxford, United Kingdom, 2 Aaron Diamond AIDS Research Center, New York, New York, United States of America
Integration into the nuclear genome of germ line cells can lead to vertical inheritance of retroviral genes as host alleles. For other viruses, germ line integration has only rarely been documented. Nonetheless, we identified endogenous viral elements (EVEs) derived from ten non-retroviral families by systematic in silico screening of animal genomes, including the first endogenous representatives of double-stranded RNA, reverse-transcribing DNA, and segmented RNA viruses, and the first endogenous DNA viruses in mammalian genomes. Phylogenetic and genomic analysis of EVEs across multiple host species revealed novel information about the origin and evolution of diverse virus groups. Furthermore, several of the elements identified here encode intact open reading frames or are expressed as mRNA. For one element in the primate lineage, we provide statistically robust evidence for exaptation. Our findings establish that genetic material derived from all known viral genome types and replication strategies can enter the animal germ line, greatly broadening the scope of paleovirological studies and indicating a more significant evolutionary role for gene flow from virus to animal genomes than has previously been recognized.
