Limited variation of the 5'cis-control region of the transmission blocking vaccine candidate Pfs25 amid great genetic diversity of Plasmodium falciparum in Cameroon

Genetic recombination during sexual reproduction within Plasmodium sp. contributes to parasite diversity and altered gene expression of certain surface markers. The pfs25 gene involved in the upset of gametocytogenesis is a candidate antigen in transmission blocking vaccine. This study investigated the polymorphism of Pfs25 within its 5’cis-control region in field isolates from different ecotypes in Cameroon. Symptomatic patients and asymptomatic healthy school children with a positive smear and from different ecozones were included. Parasite DNA was extracted and polymorphisms within pfs25, cg2-, msp-1, msp-2 and glurp genes were investigated by PCR-RFLP and DNA sequencing. Putative control elements of the 5’cis control regions of Pfs25 were identified by PCGENE software and enzymes were selected whose sequences produced or abolished restriction sites by mutations. Malaria infection was mainly caused by Plasmodium falciparum with sporadic occurrence of Plasmodium malariae and Plasmodium ovale. Analysis of the Pfs25 5’ cis-control region identified only one polymorphism (0.002%) that abolished an RsaI restriction site as part of the sequence TTTCTGTAC, located 40 bp downstream of the promoter and found at – 478 bp of the ATG. Analysis of the 5’ ciscontrol sequence of Pfs25 revealed minimal variation of the promoter region amid great zonal differences in parasite population. Altitudinal differences in parasite populations were not easily discernable.

[1]  J. Daily,et al.  Deletion analysis of the 5' flanking sequence of the Plasmodium gallinaceum sexual stage specific gene pgs28 suggests a bipartite arrangement of cis-control elements. , 2001, Molecular and biochemical parasitology.

[2]  J. Sambrook,et al.  Molecular Cloning: A Laboratory Manual , 2001 .

[3]  J. Duchemin,et al.  Plasmodium falciparum parasites in French Guiana: limited genetic diversity and high selfing rate. , 1999, The American journal of tropical medicine and hygiene.

[4]  W. Jarra,et al.  Biased distribution of msp1 and msp2 allelic variants in Plasmodium falciparum populations in Thailand. , 1999, Transactions of the Royal Society of Tropical Medicine and Hygiene.

[5]  Koen J. Dechering,et al.  Isolation and Functional Characterization of Two Distinct Sexual-Stage-Specific Promoters of the Human Malaria Parasite Plasmodium falciparum , 1999, Molecular and Cellular Biology.

[6]  C. Rogier,et al.  No influence of age on infection complexity and allelic distribution in Plasmodium falciparum infections in Ndiop, a Senegalese village with seasonal, mesoendemic malaria. , 1998, The American journal of tropical medicine and hygiene.

[7]  J. Lines,et al.  Population structure of Plasmodium falciparum in villages with different malaria endemicity in east Africa. , 1997, The American journal of tropical medicine and hygiene.

[8]  R. Dickerson,et al.  How proteins recognize the TATA box. , 1996, Journal of molecular biology.

[9]  Dimitris Thanos,et al.  Reversal of intrinsic DNA bends in the IFNβ gene enhancer by transcription factors and the architectural protein HMG I(Y) , 1995, Cell.

[10]  T. Maniatis,et al.  Virus induction of human IFNβ gene expression requires the assembly of an enhanceosome , 1995, Cell.

[11]  R Grosschedl,et al.  Assembly and function of a TCR alpha enhancer complex is dependent on LEF-1-induced DNA bending and multiple protein-protein interactions. , 1995, Genes & development.

[12]  X. Su,et al.  Sequence, transcript characterization and polymorphisms of a Plasmodium falciparum gene belonging to the heat-shock protein (HSP) 90 family. , 1994, Gene.

[13]  J. Charlwood,et al.  Random mating in a natural population of the malaria parasite Plasmodium falciparum , 1994, Parasitology.

[14]  D. Kwiatkowski,et al.  Variation in the TNF-α promoter region associated with susceptibility to cerebral malaria , 1994, Nature.

[15]  R. Barker,et al.  Use of the polymerase chain reaction to directly detect malaria parasites in blood samples from the Venezuelan Amazon. , 1994, The American journal of tropical medicine and hygiene.

[16]  R. Konings,et al.  Cloning and expression of the gene coding for the transmission blocking target antigen Pfs48/45 of Plasmodium falciparum. , 1993, Molecular and biochemical parasitology.

[17]  R. Carter,et al.  Frequency of cross-fertilization in the human malaria parasite Plasmodium falciparum , 1993, Parasitology.

[18]  J. Boothroyd,et al.  Transient transfection and expression in the obligate intracellular parasite Toxoplasma gondii , 1993, Science.

[19]  C. Sibley,et al.  Plasmodium falciparum: a simple polymerase chain reaction method for differentiating strains. , 1992, Experimental parasitology.

[20]  R. Barker,et al.  A simple method to detect Plasmodium falciparum directly from blood samples using the polymerase chain reaction. , 1992, The American journal of tropical medicine and hygiene.

[21]  R. Carter,et al.  Direct sequencing of enzymatically amplified DNA of alleles of the merozoite surface antigen MSA-1 gene from the malaria parasite Plasmodium falciparum. , 1991, Molecular and biochemical parasitology.

[22]  T. Wellems,et al.  Genetic mapping of the chloroquine-resistance locus on Plasmodium falciparum chromosome 7. , 1991, Proceedings of the National Academy of Sciences of the United States of America.

[23]  E. Winter,et al.  A DNA binding protein that recognizes oligo(dA).oligo(dT) tracts. , 1989, The EMBO journal.