法国国家科研中心3日宣布，该机构研究人员发现，一种名为“海洋浮游藻”的微藻会与一种巨型细菌交换基因，从而获取新的机能。
这种名为EhV的巨型细菌呈20面体结构，研究人员将它与“海洋浮游藻”的基因组序列进行对比发现，它们之间进行了基因互换。更令人惊奇的是，被交换的基因不止一个，而是涉及7种酶的基因，后者对合成神经酰胺至关重要。
神经酰胺是鞘脂类的中间代谢产物，在生物合成方面发挥重要作用，它可以促进细胞的新陈代谢，帮助角质蛋白有规律地再生。这种物质目前被广泛应用于护肤产品中，起到保湿、抑制黑色素生成和防止皮肤粗糙的作用。
该研究由法国国家科研中心基因组与结构信息实验室完成。研究人员表示，细菌之间发生基因交换十分普遍，细菌通过这一过程获取新的机能，比如对抗菌素产生抵抗力等，但是如此大规模的基因交换却比较少见。该研究成果已刊登在最新一期美国《基因组研究》杂志上。（生物谷Bioon.com）
生物谷推荐原始出处：
Genome Res. 2009. 19: 1441-1449 doi:10.1101/gr.091686.109
Horizontal gene transfer of an entire metabolic pathway between a eukaryotic alga and its DNA virus
Adam Monier1,5, António Pagarete2, Colomban de Vargas2,6, Michael J. Allen3, Betsy Read4, Jean-Michel Claverie1 and Hiroyuki Ogata1,6
1 Structural and Genomic Information Laboratory, CNRS-UPR2589, Mediterranean Institute of Microbiology (IFR-88), Université de la Méditerranée, Parc Scientifique de Luminy, Marseille FR-13288, France;
2 Equipe EPPO-Evolution du Plancton et PaléoOcéans, CNRS-UMR7144, Université Pierre et Marie Curie, Roscoff FR-29682, France;
3 Plymouth Marine Laboratory, Plymouth, PL1 3DH, United Kingdom;
4 Department of Biological Science, California State University San Marcos, San Marcos, California 92096-0001, USA
Interactions between viruses and phytoplankton, the main primary producers in the oceans, affect global biogeochemical cycles and climate. Recent studies are increasingly revealing possible cases of gene transfers between cyanobacteria and phages, which might have played significant roles in the evolution of cyanobacteria/phage systems. However, little has been documented about the occurrence of horizontal gene transfer in eukaryotic phytoplankton/virus systems. Here we report phylogenetic evidence for the transfer of seven genes involved in the sphingolipid biosynthesis pathway between the cosmopolitan eukaryotic microalga Emiliania huxleyi and its large DNA virus EhV. PCR assays indicate that these genes are prevalent in E. huxleyi and EhV strains isolated from different geographic locations. Patterns of protein and gene sequence conservation support that these genes are functional in both E. huxleyi and EhV. This is the first clear case of horizontal gene transfer of multiple functionally linked enzymes in a eukaryotic phytoplankton–virus system. We examine arguments for the possible direction of the gene transfer. The virus-to-host direction suggests the existence of ancient viruses that controlled the complex metabolic pathway in order to infect primitive eukaryotic cells. In contrast, the host-to-virus direction suggests that the serial acquisition of genes involved in the same metabolic pathway might have been a strategy for the ancestor of EhVs to stay ahead of their closest relatives in the great evolutionary race for survival.
