2004 Fiscal Year Final Research Report Summary
Population biology approach to the genome diversity of Plasmodium falciparum
| Project/Area Number |
15590377
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Parasitology (including Sanitary zoology)
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| Research Institution | Osaka Institute of Technology |
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Principal Investigator |
TANABE Kazuyuki Osaka Institute of Technology, Faulty of Engineering, Professor, 工学部, 教授 (40047410)
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| Co-Investigator(Kenkyū-buntansha) |
WAKI Seiji Gunma Prefecture College of Health Science, Professor, 教授 (10056286)
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| Project Period (FY) |
2003 – 2004
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| Keywords | Malaria / Plasmodium falciparum / genome / antigen / microsatellite / genotype / Vanuatu / serca |
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| Research Abstract |
1.Genetic diversity of Plasmodiumfalciparum
Since surface antigen genes of the human malaria parasite, Plasmodium falciparum, show extensive polymorphism, a rapid evolution of their polymorphism is presumed. However, little is known about frequency of the generation of novel polymorphisms. We are interested in P.falciparum populations in Vanuatu, in the southwestern Pacific, where the malaria epidemiological settings are suitable to test whether novel antigen polymorphism evolves rapidly because infections of mixed gentoypes are rare. We analyzed single nucleotidfe polymorphisms (SNPs) and repeat-length polymorphisms in three major surface antigens, msp1,msp2 and csp, in populations from 7 islands of Vanuatu in 1996 to 2002. We also sequenced simple repeat-length polymorphisms at three microsatellite loci, serca second intron, TA4O and TA 101. Analysis of more than one million bases revealed no de novo SNPs in the three antigen genes in Vanuatu. In contrast, repeat length polymorphism e
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volved rapidly. Analysis of ‘linkage disequilibrium' between pairs of loci revealed a spectrum of population genetic structure, suggesting that some of old antigen alleles have persisted through meiotic shuffling of chromosomes after the appearance of chloroquine resistance in Vanuatu. We argue that SNPs in P.falciparum antigen genes are substantially stable in isolated populations.
2.Estimation of TMRCA of Plasmodium falciparum.
The estimation of the time to the most recent common ancestor (TMRCA) of the extant populations of Plasmodium falciparuim is crucial for understanding the genetic diversity of the parasite. To estimate TMRCA, we obtained full-length sequences of two housekeeping genes, sarcoplasmic and endoplasmic reticulum Ca^<2+>-ATPase (serca) and lactate dehydrogenase (ldh), from 11 isolates of P.falciparum and one isolate of P.reichenowi, a chimpanzee malaria parasite closely related to P.falciparum. Interspecific genetic distance between the two species and intraspecific genetic distance within P.falciparum were 0.0672±0.0088 and 0.00 11±0.0007, respectively. Based on the ratio of interspecific distance to intraspecific distance, TMRCA of P.falciparum was estimated to be (8.30±5.40) x 10^4 and (11.62±7.56) x 10^4 years ago, assuming the divergence time of the two parasite species to be 5 and 7 million years ago, respectively. Less
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[Journal Article] A multiplex polymerase chain reaction for a differential diagnosis of Plasmodium falciparum and Plasmodium vivax.2004
Author(s)
Kho, W.G., Chung, J.Y, Sim, E.J., Kim, M.Y., Kim, D.W., Jongwutiwes, S., Tanabe, K.
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Journal Title
Parasitology International 53
Pages: 229-235
Description
「研究成果報告書概要(欧文)」より
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[Journal Article] Relative frequencies of polymorphisms of variation in Block 2 repeats and 5' recombinant types of Plasmodium falciparum mspl alleles.2004
Author(s)
Sakihama, N., Matsuo, T., Mitamura, T., Horii, T., Kimura, M., Kawabata, M, Tanabe, K.
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Journal Title
Parasitology International 53
Pages: 59-67
Description
「研究成果報告書概要(欧文)」より
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[Journal Article] Malaria dispersal among islands : human mediated Plasmodium falciparum gene flow in Vanuatu, Melanesia.2004
Author(s)
Lum, J.K., Kaneko, A., Tanabe, K., Takahashi, N., Bjorkman A, Kobayakawa T.
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Journal Title
Acta Tropica 90
Pages: 181-185
Description
「研究成果報告書概要(欧文)」より
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[Journal Article] Expansion of wild type allele rather than back mutation in Pfcrt explains the recent recovery of chloroquine sensitivity of Plasmodium falciparum in Malawi.2004
Author(s)
Mita, T., Kaneko, A., Lum, J.K., Zungu, I.L., Tsukahara, T., H.Eto, Kobayakawa, T.Bjorkman, A., Tanabe, K.
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Journal Title
Molecular and Biochemical Parasitology 135
Pages: 159-163
Description
「研究成果報告書概要(欧文)」より
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[Journal Article] Genetic distance in housekeeping genes between Plasmodium falciparum and Plasmodium reichenowi and within P.falciparum2004
Author(s)
Tanabe, K., Sakihama, N., Hattori, T., Ranford-Cartwright, L., Goldman, I., Escalante, A.A., Lal, A.A.
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Journal Title
Journal of Molecular Evolution 59
Pages: 687-694
Description
「研究成果報告書概要(欧文)」より
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