Studies on development of the sexual stages in Plasmodium

疟原虫性阶段发育的研究

• 批准号: 01570212
• 负责人: KAWAMOTO Fumihiko
• 金额: $ 1.41万
• 依托单位: Nagoya University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for General Scientific Research (C)
• 财政年份: 1989
• 资助国家: 日本
• 起止时间: 1989 至 1991
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-01570212/
• 关键词: Plasmodium; Sexual stage; Gametogenesis; Oocyst; Ca^<2+>-dependent pathway; cGMP-dependent pathway; Ion exchanger; DNA synthesis; 分化分育; オオキネ-ト; 生殖体形成機構; オオシスト形成機構; Na+依存性HCO3ー; Clー 交換体; Na+非依存性 Clー; HCO3ー交換体; 一価カチオン; H+ 交換体; 細胞内 pH; X線分

Induction mechanisms of gametogenesis and in vitro development of ookinetes to oocysts in a rodent malaria parasite, Plasmodium berghei, were investigated.1)Induction of gametogenesis was regulated by two distinct mechanisms, one is a low-temperature-dependent DNA synthesis and the other is a pH-dependent control of developmental events leading to microgamete assembly and exflagellation. In these events, Ca^<2+> and cGMP were found to act as second messengers.2)DNA synthesis and axoneme formation in microgametocytes were regulated by Ca^<2+>/calmodulin-dependent metabolic pathways, whereas further events to exflagellation was controlled by cGMP.3)Two separate ion exchangers, i. e., Na^+-dependent HCO_3^-(influx)/ H^+(efflux)and nonspecific-cation-dependent Cl^-(influx)/HCO_3-(efflux)exchangers, were involved in the ionic regulation in the induction of gametogenesis.4)Electron microscopy revealed that ookinetes penetrate the midgut wall of a mosquito, Anopheles omorii, by the intracellular route, although the intracellular occurrence of the parasite was also observed.5)Development of ookinetes to young oocysts was achieved in in vitro culture with or without co-cultivation of mosquito's cells. However, all of transformed young oocysts failed to develop further, i. e., neither deposition of the oocysts capsule nor nuclear division was observed.

Induction mechanisms of gametogenesis and in vitro development of ookinetes to oocysts in a rodent malaria parasite, Plasmodium berghei, were investigated.1)Induction of gametogenesis was regulated by two distinct mechanisms, one is a low-temperature-dependent DNA synthesis and the other is a pH-dependent control of developmental events leading to microgamete assembly and exflagellation.在这些事件中，发现Ca^<2+>和CGMP充当第二个使者。2）微聚糖细胞中的DNA合成和轴突形成受CA^<2+>/钙调蛋白依赖的代谢途径的调节，而CGMP.3）二离子ion issersers，cgmp.3），而进一步的事件则受到了进一步的事件。 e。，na^+ - 依赖性hco_3^ - （涌入）/ h^+（外排）和非特异性c依赖性cl^ - （涌入）/ hco_3-（flux）/ hco_3-（feffux）交换器，参与了配子发生的离子调节。通过细胞内途径，尽管也观察到寄生虫的细胞内发生。但是，所有转变的年轻卵囊都无法进一步发展。例如，均未观察到卵囊胶囊的沉积和核分裂。

项目成果

F.Kawamoto: "Plasmodium berghei:Ionic regulation and the induction of gametogenesis" Experimental Parasitology.

F.Kawamoto：“伯氏疟原虫：离子调节和配子发生的诱导”实验寄生虫学。

Kawamoto, F.: "Ca2+/calmodulin-dependent DNA synthesis in microgametogenesis of Plasmodium berghei." Mol. Biochem. Parasitol.

Kawamoto, F.：“伯氏疟原虫小配子发生过程中 Ca2/钙调蛋白依赖性 DNA 合成。”

Kawamoto, F.: "Possible roles of Ca^<2+> and cGMP in the exflagellation of Plasmodium berghei and P. falciparum." Mol. Biochem. Parasitol.42(2). 101-108 (1990)

Kawamoto, F.：“Ca^2 和 cGMP 在伯氏疟原虫和恶性疟原虫的鞭毛中的可能作用。”

Syafruddin: "Development of Plasmodium berghei ookinetes to young oocysts in vitro" J.Protozool.,. 39(2).

Syafruddin：“伯氏疟原虫动合子在体外发育为幼卵囊”J.Protozool.,。

Kawamoto,F.: "Possible roles of Ca2+and cGMP in the exflagellation of Plasmodium berghei and P.falciparum." Mol.Biochem.Parasitol.42(2). 101-108 (1990)

Kawamoto,F.：“Ca2 和 cGMP 在伯氏疟原虫和恶性疟原虫的鞭毛中的可能作用。”