THE FINE STRUCTURE OF THE EXOERYTHROCYTIC STAGES OF PLASMODIUM FALLAX
THE FINE STRUCTURE OF THE EXOERYTHROCYTIC STAGES OF PLASMODIUM FALLAX
复制标题
疟原虫红细胞外阶段的精细结构
作者：
P. K. Hepler;C. G. Huff;H. Sprinz
使用在固定于戊二醛-OsO4 中的胚胎火鸡脑细胞衍生的组织培养系统中生长的制剂，分析了禽类疟疾寄生虫（法拉克斯疟原虫）的红细胞外循环的精细结构。成熟的裂殖子是一个长 3 到 4 µ 、宽 1 到 2 µ 的细长细胞，被包裹在复杂的双层薄膜中。前端由一个圆锥体组成，从圆锥体中发出两个有叶的成对细胞器和几个紧密相关的致密体。细胞核位于细胞的中部，而在后端发现了包裹在球形体周围的单个线粒体。在靠近细胞核的裂殖子的表膜上，有一个直径为 80 至 100 mμ 的细胞造口腔。根据精细结构的变化，随后的发育顺序分为三个阶段：一是去分化阶段，裂殖子失去圆锥形、成对细胞器、致密体、球体、厚膜内层等复杂结构，转变为滋养体；第二，生长期，包括许多核分裂以及线粒体、内质网和核糖体的平行增加；第三，再分化和细胞质裂殖阶段，其中，随着新的裂殖子从母裂殖体中萌芽，特化的细胞器重新出现。
The fine structure of the exoerythrocytic cycle of an avian malarial parasite, Plasmodium fallax, has been analyzed using preparations grown in a tissue culture system derived from embryonic turkey brain cells which were fixed in glutaraldehyde-OsO4. The mature merozoite, an elongated cell 3- to 4-µ long and 1- to 2-µ wide, is ensheathed in a complex double-layered pellicle. The anterior end consists of a conoid, from which emanate two lobed paired organelles and several closely associated dense bodies. A nucleus is situated in the mid portion of the cell, while a single mitochondrion wrapped around a spherical body is found in the posterior end. On the pellicle of the merozoite near the nucleus a cytostomal cavity, 80 to 100 mµ in diameter, is located. Based on changes in fine structure, the subsequent sequence of development is divided into three phases: first, the dedifferentiation phase, in which the merozoite loses many complex structures, i.e. the conoid, paired organelles, dense bodies, spherical body, and the thick inner layers of the pellicle, and transforms into a trophozoite; second, the growth phase, which consists of many nuclear divisions as well as parallel increases in mitochondria, endoplasmic reticulum, and ribosomes; and third, the redifferentiation and cytoplasmic schizogony phase, in which the specialized organelles reappear as the new merozoites bud off from the mother schizont.