Bruce M C, Alano P, Duthie S, Carter R
Department of Genetics, University of Edinburgh, Scotland.
Parasitology. 1990 Apr;100 Pt 2:191-200. doi: 10.1017/s0031182000061199.
Blood-stage malaria parasites in the vertebrate host can develop either into the asexual, multiplying forms, called schizonts, or into gametocytes, the sexual stages of the parasite. In the present work we studied the differentiation into asexual parasites or gametocytes of the progeny of single, isolated schizonts of the clone 3D7A of Plasmodium falciparum, using monoclonal antibodies specific for the sexual or asexual stages of the parasite. We observed that schizonts obtained from a continuous culture undergoing serial cycles of growth and dilution with fresh red blood cells produced either only gametocytes or only asexual parasites, showing a high degree of commitment to one or the other developmental pathway. The relative proportion of schizonts which produced gametocytes was very low at low parasite densities in culture, while at high parasite densities a much greater proportion of schizonts produced gametocytes. Nevertheless, at both low and high parasite densities individual schizonts were almost always fully committed to producing only gametocytes or only asexual parasites.
脊椎动物宿主体内的血液期疟原虫可发育成无性繁殖形式，即裂殖体，也可发育成配子体，即疟原虫的有性阶段。在本研究中，我们利用针对疟原虫有性或无性阶段的单克隆抗体，研究了恶性疟原虫克隆3D7A单个分离裂殖体后代向无性寄生虫或配子体的分化情况。我们观察到，从经过连续生长和用新鲜红细胞稀释的连续培养物中获得的裂殖体，要么只产生配子体，要么只产生无性寄生虫，显示出对一种或另一种发育途径的高度定向性。在低密度培养条件下，产生配子体的裂殖体相对比例很低，而在高密度寄生虫条件下，产生配子体的裂殖体比例要高得多。然而，在低密度和高密度寄生虫条件下，单个裂殖体几乎总是完全定向于只产生配子体或只产生无性寄生虫。
