@article{fdi:010044122,
  title = {{T}he promastigote surface antigen gene family of the {L}eishmania parasite : differential evolution by positive selection and recombination - art. no. 292},
  author = {{D}evault, {A}. and {B}anuls, {A}nne-{L}aure},
  editor = {},
  language = {{ENG}},
  abstract = {{B}ackground: {PSA} (promastigote surface antigen) is one of the major classes of membrane proteins present at the surface of the parasitic protozoan {L}eishmania. {W}hile it harbours leucine rich repeats, which are suggestive of its involvement in parasite-to-host physical interactions, its exact role is largely unknown. {F}urthermore, the extent of diversity of this gene family, both in copy number and sequence has not been established. {R}esults: {F}rom the newly available complete genome sequences of {L}. major, {L}. infantum and {L}. braziliensis, we have established the complete list of {PSA} genes, based on the conservation of specific domain architecture. {T}he latter includes an array of leucine rich repeats of unique signature flanked by conserved cysteine-rich domains. {A}ll {PSA} genes code either for secreted or membrane-anchored surface proteins. {B}esides the few previously identified {PSA} genes, which are shown here to be part of a relatively large subclass of {PSA} genes located on chromosome 12, this study identifies seven other {PSA} subtypes. {T}he latter, whose genes lie on chromosomes 5, 9, 21 and 31 in all three species, form single gene ( two genes in one instance) subfamilies, which phylogenetically cluster as highly related orthologs. {O}n the other hand, genes found on chromosome 12 generally show high diversification, as reflected in greater sequence divergence between species, and in an extended set of divergent paralogs. {M}oreover, we show that the latter genes are submitted to strong positive selection. {W}e also provide evidence that evolution of these genes is driven by intra- and intergenic recombination, thereby modulating the number of {LRR}s in protein and generating chimeric genes. {C}onclusion: {PSA} is a {L}eishmania family of membrane-bound or secreted proteins, whose main signature consists in a specific {LRR} sequence. {A}ll {PSA} genes found in the genomes of three sequenced {L}eishmania species unambiguously distribute into eight subfamilies of orthologs. {S}even of these are evolving relatively slowly and could correspond to basic functions related to parasite/host interactions. {O}n the opposite, the other {PSA} gene class, which include all so far experimentally studied {PSA} genes, could be involved in more specialised adaptative functions.},
  keywords = {},
  booktitle = {},
  journal = {{BMC} {E}volutionary {B}iology},
  volume = {8},
  numero = {292},
  pages = {24},
  ISSN = {1471-2148},
  year = {2008},
  DOI = {10.1186/1471-2148-8-292},
  URL = {https://www.documentation.ird.fr/hor/fdi:010044122},
}