THE FINE STRUCTURE OF GIARDIA MURIS
THE FINE STRUCTURE OF GIARDIA MURIS
复制标题
贾第鞭毛虫的精细结构
作者：
D. Friend
贾第鞭毛虫是一种非侵入性的肠道鞭毛虫。本电子显微镜研究显示了小鼠十二指肠腔内贾第鞭毛虫滋养体的精细结构，因为它出现在戊二醛和丙烯醛联合固定和四氧化锇后固定后。鼠贾第鞭毛虫为泪滴状，前圆形，背面外凸，腹面内凹。腹侧表面的前三分之二被修改以形成粘附盘。粘连盘分为2个瓣，其内侧表面形成中间沟。边缘沟是粘着盘的侧脊和周围细胞质的突出部分之间的空间。该生物体有2个核，1个背侧到每个叶的粘合盘。在细胞核的前极之间，基部产生8对鞭毛。贾第鞭毛虫特有的中间体位于核的后极之间。细胞质中含有类似颗粒糖原的300-A颗粒，类似核糖体的150- 200-A颗粒和梭形裂隙。细胞周边的背侧部分被扁平的空泡的线性阵列占据，其中一些包含致密颗粒的簇。腹外侧细胞质由规则排列的粗细丝和细丝组成，这些细丝在粘着盘周围延伸成条纹状凸缘。粘附盘由一层微管组成，微管通过规则间隔的纤维带与细胞质连接。质膜覆盖在椎间盘的腹侧和侧面。中间体由弯曲的微管的椭圆形聚集体组成。微管从中间体向腹侧延伸，与尾鞭毛并排。尾鞭毛、侧鞭毛和前鞭毛的胞质内部分的行程相当长，伴随着与它们的外双鞭毛相邻的中空细丝。前鞭毛的胞质内部分也伴有细颗粒状的杆状体。没有识别出线粒体、滑面内质网、高尔基复合体、溶酶体或轴杆的结构。
Giardia is a noninvasive intestinal zooflagellate. This electron microscope study demonstrates the fine structure of the trophozoite of Giardia muris in the lumen of the duodenum of the mouse as it appears after combined glutaraldehyde and acrolein fixation and osmium tetroxide postfixation. Giardia muris is of teardrop shape, rounded anteriorly, with a convex dorsal surface and a concave ventral one. The anterior two-thirds of the ventral surface is modified to form an adhesive disc. The adhesive disc is divided into 2 lobes whose medial surfaces form the median groove. The marginal grooves are the spaces between the lateral crests of the adhesive disc and a protruding portion of the peripheral cytoplasm. The organism has 2 nuclei, 1 dorsal to each lobe of the adhesive disc. Between the anterior poles of the nuclei, basal bodies give rise to 8 paired flagella. The median body, unique to Giardia, is situated between the posterior poles of the nuclei. The cytoplasm contains 300-A granules that resemble particulate glycogen, 150- to 200-A granules that resemble ribosomes, and fusiform clefts. The dorsal portion of the cell periphery is occupied by a linear array of flattened vacuoles, some of which contain clusters of dense particles. The ventrolateral cytoplasm is composed of regularly packed coarse and fine filaments which extend as a striated flange around the adhesive disc. The adhesive disc is composed of a layer of microtubules which are joined to the cytoplasm by regularly spaced fibrous ribbons. The plasma membrane covers the ventral and lateral surfaces of the disc. The median body consists of an oval aggregate of curved microtubules. Microtubules extend ventrally from the median body to lie alongside the caudal flagella. The intracytoplasmic portions of the caudal, lateral, and anterior flagella course considerable distances, accompanied by hollow filaments adjacent to their outer doublets. The intracytoplasmic portions of the anterior flagella are accompanied also by finely granular rodlike bodies. No structures identifiable as mitochondria, smooth endoplasmic reticulum, the Golgi complex, lysosomes, or axostyles are recognized.