Landau I, Miltgen F, Boulard Y, Chabaud A G, Baccam D
Ann Parasitol Hum Comp. 1979 Mar-Apr;54(2):145-61.
The study of the gametocytes of Plasmodium yoelii enabled the differentiation of 4 morphological types: O, I, II and III (in a chronological order) and amongst each of these types the differentiation of healthy and altered gametocytes. These morphological data represent a tool for investigations on the biology of the gametocytes of the "vivax" group. Preliminary experiments bring informations on the evolution of gametocytes and the mechanisms of their infectivity. 1--In experimentaly infected white mice gametocytes of P.y. nigeriensis are infective up to the 3rd-4th day, those of P. y. yoelii until the 5th-6th days. These periods can be shorter when the infection is very virulent or longer when chronical. 2--The drop in infectivity coincides with the increase in number of the altered gametocytes. 3--The loss of infectivity is connected with the condition of the blood: when parasitaemiae are high, it becomes rapidly unsuitable to a normal evolution of the gametocytes: thus, non infective gametocytes acquire a good infectivity in less than two hours when transfered to a clean mouse. 4--The gametocytic composition of the blood taken up by the Anopheles in the capillaries can be very different from that taken at the tail of a Rodent. In the young parasitaemiae, when the Rodents are most infective to the Mosquitoes, there is a considerable enrichment in gametocytes O-I of the blood ingested by the Anopheles as compared to that taken from the Rodents by the usual techniques. This phenomenon could perhaps be explained by the larger size of gametocytes O and I and their retention in the capillaries of the host. 5--The strong infectivity of gametocytes O and I is confirmed by the fact that no infection develops in the Mosquitoes when no such gametocytes are present in the ingested blood. 6--The ageeing of gametocytes appears to be very rapid for gametocytes arising from exo-erythrocytic schizontes reach stage II, 29 hours and stage III, 35 hours, after the rupture of the very first schizonts.
约氏疟原虫配子体的研究使得能够区分出4种形态类型：O型、I型、II型和III型（按时间顺序），并且在每种类型中又能区分出健康的和形态改变的配子体。这些形态学数据是研究“间日疟”组配子体生物学的一种工具。初步实验提供了关于配子体发育及感染机制的信息。1——在实验感染的小白鼠中，约氏疟原虫尼日尔亚种的配子体在第3 - 4天仍具感染性，约氏疟原虫约氏亚种的配子体直到第5 - 6天仍具感染性。当感染毒性很强时，这些时期可能会更短；当感染为慢性时，时期可能会更长。2——感染性的下降与形态改变的配子体数量增加相一致。3——感染性的丧失与血液状况有关：当疟原虫血症很高时，它会迅速变得不适于配子体的正常发育；因此，将非感染性配子体转移到健康小鼠体内后，它们在不到两小时内就会获得良好的感染性。4——按蚊在毛细血管中摄取的血液中的配子体组成可能与从啮齿动物尾部采集的血液中的配子体组成非常不同。在疟原虫血症初期，当啮齿动物对蚊子的感染性最强时，与通过常规技术从啮齿动物采集的血液相比，按蚊摄取的血液中O - I型配子体有相当程度的富集。这种现象可能是由于O型和I型配子体较大且滞留在宿主的毛细血管中所致。5——当摄取的血液中不存在此类配子体时，蚊子不会发生感染，这一事实证实了O型和I型配子体具有很强的感染性。6——对于由红细胞外裂殖子产生的配子体而言，配子体的老化似乎非常迅速，在最初的裂殖子破裂后，它们在29小时达到II期，在35小时达到III期。
