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.

研究了啮齿类疟原虫伯氏疟原虫配子发生的诱导机制以及动合子在体外发育为卵囊的机制。 1)配子发生的诱导受到两种不同机制的调节，一种是低温依赖性DNA合成，另一种是低温依赖性DNA合成。对导致微配子组装和鞭打的发育事件的pH依赖性控制。在这些事件中，Ca^2+和cGMP被发现充当第二信使。2)小配子细胞中的DNA合成和轴丝形成受到Ca^2+/钙调蛋白依赖性代谢途径的调节，而进一步的事件则为鞭毛化。由cGMP控制。3)两个独立的离子交换器，i。即Na^+依赖性HCO_3^-(流入)/H^+(流出)和非特异性阳离子依赖性Cl^-(流入)/HCO_3-(流出)交换子，参与诱导中的离子调节4）电子显微镜显示，动动子通过细胞内途径穿透蚊子（Anopheles omorii）的中肠壁，尽管动动子在细胞内发生还观察到了寄生虫。5)在有或没有蚊子细胞共培养的体外培养中实现了动动子向幼卵囊的发育。然而，所有转化的年轻卵囊未能进一步发育，即。即，既没有观察到卵囊囊的沉积，也没有观察到核分裂。

项目成果

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。”

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。”

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。”