@article{PAR00007732,
  title = {{M}imivirus shows dramatic genome reduction after intraamoebal culture},
  author = {{B}oyer, {M}. and {A}zza, {S}. and {B}arrassi, {L}. and {K}lose, {T}. and {C}ampocasso, {A}. and {P}agnier, {I}. and {F}ournous, {G}. and {B}org, {A}. and {R}obert, {C}. and {Z}hang, {X}. {Z}. and {D}esnues, {C}. and {H}enrissat, {B}. and {R}ossmann, {M}. {G}. and {L}a {S}cola, {B}. and {R}aoult, {D}idier},
  abstract = {{M}ost phagocytic protist viruses have large particles and genomes as well as many laterally acquired genes that may be associated with a sympatric intracellular life (a community-associated lifestyle with viruses, bacteria, and eukaryotes) and the presence of virophages. {B}y subculturing {M}imivirus 150 times in a germ-free amoebal host, we observed the emergence of a bald form of the virus that lacked surface fibers and replicated in a morphologically different type of viral factory. {W}hen studying a 0.40-mu m filtered cloned particle, we found that its genome size shifted from 1.2 ({M}1) to 0.993 {M}b ({M}4), mainly due to large deletions occurring at both ends of the genome. {S}ome of the lost genes are encoding enzymes required for post-translational modification of the structural viral proteins, such as glycosyltransferases and ankyrin repeat proteins. {P}roteomic analysis allowed identification of three proteins, probably required for the assembly of virus fibers. {T}he genes for two of these were found to be deleted from the {M}4 virus genome. {T}he proteins associated with fibers are highly antigenic and can be recognized by mouse and human antimimivirus antibodies. {I}n addition, the bald strain ({M}4) was not able to propagate the sputnik virophage. {O}verall, the {M}imivirus transition from a sympatric to an allopatric lifestyle was associated with a stepwise genome reduction and the production of a predominantly bald virophage resistant strain. {T}he new axenic ecosystem allowed the allopatric {M}imivirus to lose unnecessary genes that might be involved in the control of competitors.},
  keywords = {allopatry ; experimental evolution ; giant virus ; virus evolution},
  journal = {{P}roceedings of the {N}ational {A}cademy of {S}ciences of the {U}nited {S}tates of {A}merica},
  volume = {108},
  numero = {25},
  pages = {10296--10301},
  ISSN = {0027-8424},
  year = {2011},
  DOI = {10.1073/pnas.1101118108},
  URL = {http://www.documentation.ird.fr/hor/{PAR}00007732},
}