Objective: To sequence a gene encoding GLURP and identify the genotypes of geographically different Plasmodium falciparum isolates from Yunnan and Hainan Provinces, China.
Methods: The gene of R2 repeat region of GLURP was amplified by the nested polymerase chain reaction and cloned into T-vector. The nucleotide sequence of the GLURP gene was determined using automatic sequencer (dideoxy chain termination method), and analyzed by DNA Star software.
Results: At least 7 different GLURP genotypes ranging from 600 bp to 1,500 bp were found in different P. falciparum isolates from Yunnan and Hainan Provinces. R2 region of GLURP gene consisted of several repeat units, each was composed of 19-20 residues which were shown to be highly conserved. The GLURP gene was also size polymorphic due to differences in the number of repeat units, whereas the repeat sequence was conserved. Sequence analysis showed that DNA sequences and deduced amino acid sequences were highly homologous among the geographically dispersed isolates or various isolates from the same geographical region. No obvious differences were found in the GLURP gene sequences among geographically different isolates.
Conclusion: The GLURP gene of geographically different P. falciparum isolates is highly conserved and size polymorphic, being useful in searching for malaria vaccine candidate antigen and developing a genotyping method for malaria research.