“巨病毒”（giant virus）分離毒株來(lái)自英國(guó)Bradford的一個(gè)冷卻塔,。最初因其大?。ㄊ亲畲笠阎《镜娜洞?，而且大于很多細(xì)菌）該病毒被誤為一種細(xì)菌,，它是在名為“Acanthamoeba polyphaga”的原生動(dòng)物中發(fā)現(xiàn)的,。當(dāng)它被識(shí)別為一種病毒時(shí),，它被稱之為一種模仿病毒（mimivirus,，因其與細(xì)菌相似而得名），正式稱謂為APMV (Acanthamoeba polyphaga mimivirus),。
現(xiàn)在,，一種新的、甚至更大的APMV毒株（名為“mamavirus”）已從巴黎一個(gè)水冷卻塔中分離出來(lái)。引人注目的是,，該病毒并不是孤立的,，其本身還被一種“衛(wèi)星病毒”（satellite virus）所寄生。被稱為Sputnik的這種病毒在“建造”在被APMV共感染的阿米巴中的“病毒工廠”中復(fù)制,。比照噬菌體,，Sputnik被看作是人們所發(fā)現(xiàn)的第一種噬病毒體（virophage）。它也許只是一座噬病毒體冰山之一角,，因?yàn)閷?duì)海洋水域所進(jìn)行的宏基因組學(xué)研究顯示,，存在大量與巨病毒密切相關(guān)的基因序列，從而導(dǎo)致人們懷疑：它們是一種共同的浮游生物寄生蟲(chóng),。（生物谷Bioon.com）
生物谷推薦原始出處：
Nature 455, 100-104 (4 September 2008) | doi:10.1038/nature07218
The virophage as a unique parasite of the giant mimivirus
Bernard La Scola1,6, Christelle Desnues1,6, Isabelle Pagnier1, Catherine Robert1, Lina Barrassi1, Ghislain Fournous1, Michèle Merchat2, Marie Suzan-Monti1, Patrick Forterre3,4, Eugene Koonin5 & Didier Raoult1
Viruses are obligate parasites of Eukarya, Archaea and Bacteria.Acanthamoeba polyphaga mimivirus (APMV) is the largest known virus; it grows only in amoeba and is visible under the optical microscope. Mimivirus possesses a 1,185-kilobase double-stranded linear chromosome whose coding capacity is greater than that of numerous bacteria and archaea1, 2, 3. Here we describe an icosahedral small virus, Sputnik, 50 nm in size, found associated with a new strain of APMV. Sputnik cannot multiply in Acanthamoeba castellanii but grows rapidly, after an eclipse phase, in the giant virus factory found in amoebae co-infected with APMV4. Sputnik growth is deleterious to APMV and results in the production of abortive forms and abnormal capsid assembly of the host virus. The Sputnik genome is an 18.343-kilobase circular double-stranded DNA and contains genes that are linked to viruses infecting each of the three domains of life Eukarya, Archaea and Bacteria. Of the 21 predicted protein-coding genes, eight encode proteins with detectable homologues, including three proteins apparently derived from APMV, a homologue of an archaeal virus integrase, a predicted primase–helicase, a packaging ATPase with homologues in bacteriophages and eukaryotic viruses, a distant homologue of bacterial insertion sequence transposase DNA-binding subunit, and a Zn-ribbon protein. The closest homologues of the last four of these proteins were detected in the Global Ocean Survey environmental data set5, suggesting that Sputnik represents a currently unknown family of viruses. Considering its functional analogy with bacteriophages, we classify this virus as a virophage. The virophage could be a vehicle mediating lateral gene transfer between giant viruses.
