Molecular and cellbiological studies on gametocytogenesis of a malaria parasite, Plasmodium falciparum

疟原虫恶性疟原虫配子细胞发生的分子和细胞生物学研究

基本信息

批准号：
12670230
负责人：
KAWAMOTO Fumihiko
金额：
$ 2.18万
依托单位：
Nagoya University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
2000
资助国家：
日本
起止时间：
2000 至 2001
项目状态：
已结题

项目摘要

Induction mechanism of gametocytogenesis in a malaria parasite, Plasmodium falciparum was investigated cell-biologically and molecularly, using wild isolates.1. Induction of gametocytogenesis in wild isolates : Induction methods of gametocytogenesis was studied, using wild isolates collected from Myanmar and Indonesia.Gametocytogenesis was observed when the parasite density reached to ca. 5% and then they were cultivated at 3-4 times higher concentrations of RBC than normal culture condition. All wild isolates adapted for in vitro cultivation were capable in forming gametocytes, and their transformation rates reached to 50-70%.2. Induction ofgametocytogenesis by glucose deficiency : As gametocytogenesis was induced by cultivation at higher RBC concentration, it was speculated that nutrient deficiency, particularly glucose, may play important role in triggering this phenomenon. In fact, addition of glucose into the medium inhibited the induction of gametocytogenesis. Furthermore, addition of 2-deoxy glucose was capable in inducing it under a normal culture condition, although a great decrease ofparasitaemia was observed. These results indicated that glucose deficiency might play an important role in inducing gametocytogenesis.3. Trials of induction ofgametocytogenesis in established strains : Using FCR-3 and K-l strains, induction of gametocytogenesis was examined as like in wild isolates, but no gametocyte was formed, suggesting that important genes for induction of gametocytogenesis might be deleted in these strains.4. Identification of master gene(s) for induction of gametocytogenesis : Using a subtraction method between mRNA isolated from gametocyogenesis-induced and non-induced parasites, master gene(s) which may regulate gametocytogenesis was investigated. However, all clones obtained after the subtraction were only heat shock protein genes, and expected genes, such as cAMP-dependent kinases, were not detected.

使用野生分离株，对疟疾寄生虫，恶性疟原虫的诱导机制进行了生物学和分子研究。1。使用从缅甸和印度尼西亚收集的野生分离株研究了野生分离株中配子细胞发生的诱导方法。 5％，然后它们以RBC的浓度高3-4倍，是正常培养条件的3-4倍。适用于体外培养的所有野生分离株均能够形成配子细胞，其转化率达到50-70％.2。通过葡萄糖缺乏诱导的摄氏诱导：由于在较高的RBC浓度下栽培引起了植物生成，因此据推测，营养缺乏症，尤其是葡萄糖，可能在触发这种现象中起重要作用。实际上，将葡萄糖添加到培养基中会抑制诱导配子细胞的诱导。此外，尽管观察到大量降低parasitaemia，但添加2-脱氧葡萄糖能够在正常培养条件下诱导它。这些结果表明，葡萄糖缺乏可能在诱导配子细胞生成中起重要作用。3。在既定菌株中诱导结t的试验：使用FCR-3和K-L菌株，像在野生分离株中一样检查了配子细胞生成的诱导，但没有形成配子细胞，这表明在这些菌株中可以删除该诱导的配子细胞生成的重要基因。4.4。鉴定主基因诱导配子细胞生成的鉴定：使用从配子形成诱导的和非诱导的寄生虫分离的mRNA之间的减法方法，研究了可能调节配子细胞生成的主要基因。但是，在减法后获得的所有克隆仅是热休克蛋白基因，而未检测到预期的基因，例如cAMP依赖性激酶。