法国研究人员日前在单细胞生物阿米巴变形虫体内发现了一种新的巨型病毒，并为其取名“马赛病毒”（Marseillevirus）。
艾克斯－马赛大学传染病和热带病研究小组的负责人迪迪埃·拉乌尔9日向媒体介绍了这种巨型病毒。他说，这是一种全新的病毒，其基因组构成与其他种类的病毒差别很大。研究人员同时发现，它与其他寄居在阿米巴变形虫体内的微生物进行过基因交换，这些微生物包括细菌和其他巨型病毒。据介绍，“马赛病毒”直径约为250毫微米，其基因组包含36．8万个碱基对。
此前，法国科学家曾在阿米巴变形虫体内发现过一种名为Mamavirus的巨型病毒，大小几乎与小型细菌差不多，用普通显微镜就能够观察到它的存在。研究人员认为，这说明阿米巴变形虫体内存在一套机制，能不断产生新的病毒。
该研究成果已刊登在最新一期美国《国家科学院学报》上。（生物谷Bioon.com）
生物谷推荐原始出处：
PNAS December 9, 2009, doi: 10.1073/pnas.0911354106
Giant Marseillevirus highlights the role of amoebae as a melting pot in emergence of chimeric microorganisms
Micka?l Boyera,1, Natalya Yutinb,1, Isabelle Pagniera, Lina Barrassia, Ghislain Fournousa, Leon Espinosaa, Catherine Roberta, Sa?d Azzaa, Siyang Sunc, Michael G. Rossmannc,2, Marie Suzan-Montia,3, Bernard La Scolaa, Eugene V. Kooninb and Didier Raoulta,2
aUnité de Recherche sur les Maladies Infectieuses et Tropicales Emergentes, Centre National de la Recherche Scientifique, Unité Mixte de Recherche, Institut de Recherche pour le Développement 6236, Faculté de Médecine, Université de la Méditerranée, 13385 Marseille Cedex 5, France;
bNational Center for Biotechnology Information, National Library of Medicine, National Institutes of Health, Bethesda, MD 20894; and
cDepartment of Biological Sciences, Purdue University, West Lafayette, IN 47907
Giant viruses such as Mimivirus isolated from amoeba found in aquatic habitats show biological sophistication comparable to that of simple cellular life forms and seem to evolve by similar mechanisms, including extensive gene duplication and horizontal gene transfer (HGT), possibly in part through a viral parasite, the virophage. We report here the isolation of “Marseille” virus, a previously uncharacterized giant virus of amoeba. The virions of Marseillevirus encompass a 368-kb genome, a minimum of 49 proteins, and some messenger RNAs. Phylogenetic analysis of core genes indicates that Marseillevirus is the prototype of a family of nucleocytoplasmic large DNA viruses (NCLDV) of eukaryotes. The genome repertoire of the virus is composed of typical NCLDV core genes and genes apparently obtained from eukaryotic hosts and their parasites or symbionts, both bacterial and viral. We propose that amoebae are “melting pots” of microbial evolution where diverse forms emerge, including giant viruses with complex gene repertoires of various origins.
