A superfamily of variant genes encoded in the subtelomeric region of Plasmodium vivax.
The malarial parasite Plasmodium vivax causes disease in humans, including chronic infections and recurrent relapses, but the course of infection is rarely fatal, unlike that caused by Plasmodium falciparum. To investigate differences in pathogenicity between P. vivax and P. falciparum, we have compared the subtelomeric domains in the DNA of these parasites. In P. falciparum, subtelomeric domains are conserved and contain ordered arrays of members of multigene families, such as var, rif and stevor, encoding virulence determinants of cytoadhesion and antigenic variation. Here we identify, through the analysis of a continuous 155,711-base-pair sequence of a P. vivax chromosome end, a multigene family called vir, which is specific to P. vivax. The vir genes are present at about 600-1,000 copies per haploid genome and encode proteins that are immunovariant in natural infections, indicating that they may have a functional role in establishing chronic infection through antigenic variation.
del Portillo
H A
HA
Departamento de Parasitologia, Instituto de Ciências Biomédicas, Universidade de São Paulo, Av. Lineu Prestes 1374, São Paulo, SP 05508-900, Brazil. hernando@icb.usp.br
Fernandez-Becerra
C
C
Bowman
S
S
Oliver
K
K
Preuss
M
M
Sanchez
C P
CP
Schneider
N K
NK
Villalobos
J M
JM
Rajandream
M A
MA
Harris
D
D
Pereira da Silva
L H
LH
Barrell
B
B
Lanzer
M
M
D000328:Adult; D000818:Animals; D000913:Antibodies, Protozoan / Q000276:immunology; D018244:Chromosomes, Artificial, Yeast; D016054:DNA, Protozoan; D015723:Gene Library; D017125:Genes, Protozoan; D014644:Genetic Variation; D006801:Humans; D016780:Malaria, Vivax / Q000469:parasitology; D005810:Multigene Family; D010963:Plasmodium falciparum / Q000235:genetics / Q000472:pathogenicity; D010966:Plasmodium vivax / Q000235:genetics* / Q000276:immunology / Q000472:pathogenicity; D015800:Protozoan Proteins / Q000235:genetics / Q000276:immunology; D011544:Pseudogenes; D020133:Reverse Transcriptase Polymerase Chain Reaction; D016615:Telomere
D000913:Antibodies, Protozoan; D016054:DNA, Protozoan; D015800:Protozoan Proteins