ULTRASTRUCTURE OF THE FLAGELLUM IN SPERM OF CKCINELLA SEPTEMPUNCTATA

Abstract  Using cell whole mount preparation and ultrathin section technique, the ultrastructure of the flagellum in the sperm of Coccinella septempunctata L. was examined with transmission electron microscope. The flagellum is made up of a classic 9+9+2 axoneme containing two similar crystallized mitochondria1 derivatives, two accessory bodies, which are divided in to two portions, an osmiophilic dense crescent and a spongy one, and a non-crystalline body. At the end of the flagellum, only the axoneme is present, it loses the two central microtubules but retains the nine doublets with dynein arms and the nine accessory microtubules.     

七星瓢虫精子鞭毛的超微结构(英文)

应用细胞整装制备和超薄切片技术,在透射电子显微镜下检查了七星瓢虫成熟精子鞭毛的超微结构。精子鞭毛是由一个典型的9＋9＋2轴丝,两个同形结晶的线粒体衍生物,两个附体（每个附体具有两部分,一个嗜锇致密月牙体和一个海绵月牙体）和一个非结晶体组成,在鞭毛终端部,仅存的轴丝失去了两个中央微管保留了9个具有动力蛋白臂的双微管和9个附微管。     

FINE STRUCTURAL CHANGES IN THE FLAGELLUM OF THE SPERMATID IN EXPERIMENTAL CRYPTORCHIDISM OF THE RAT

Rat testes were confined to the abdominal cavity by operation. After 1 to 26 days they were excised, fixed with osmium tetroxide, sectioned, and examined with the electron microscope. Changes in the axial filament complex of the spermatid flagellum appeared 2 days after operation, and the arrangement of filaments in the middle- and main pieces of some spermatid tails was disordered as compared to the 9 + 2 filament arrangement in the tails of the control spermatids and in other flagella and cilia. In cross-sections, the filaments in the experimental material were nine or less in number, and each of them was single and dense. Occasionally some were double, and in those instances one filament was dense and the other was light and tubular. The central filaments were obscure. In longitudinal sections,the filaments were not parallel to the main axis of the flagella or to each other. It was assumed that the central filaments were more sensitive to the experimental conditions than the peripheral pairs of filaments. Furthermore, the light filaments of the peripheral pairs were more sensitive than the dense filaments. Besides the axial filament complex, the fibrous sheath which surrounds it in the main piece was also changed. The plasma membrane of the changed flagella disappeared or became fragmented.     

THE PRESENCE OF A GELATIN-LIQUEFYING ENZYME IN CRUDE PEPSIN PREPARATIONS

A protein fraction has been isolated from crude pepsin preparations which is about 400 times as active as crystalline pepsin in the lique-faction of gelatin. The activity as measured by the digestion of casein, edestin or egg albumin is less than that of crystalline pepsin. It is more resistant to alkali than the crystalline pepsin.     

IN SITU PRESERVATION OF THE TRANSVERSE FLAGELLUM OF PERIDINIUM CINCTUM (DINOPHYCEAE) FOR SCANNING ELECTRON MICROSCOPY1

Three-dimensional structure of the transverse flagellum was studied by means of scanning electron microscopy (SEM) in Peridinium cinctum (O.F.M.) Ehrenberg. Several fixation and dehydration procedures were compared. Cells fixed, rapidly in 1% osmium tetroxide and critical-point dried showed accurate preservation of structural features seen in living cells; in particular, both transverse and posterior flagella were retained in the furrows on the cell surface. Osmium-fixed and freeze-dried, samples were prone to cellular collapse and loss of flagella. Glutar-aldehyde-fixed and critical-point dried cells showed a layer of material covering the thecal plates, most conspicuously over the girdle region; flagella were absent. Stereo-pair micrographs illustrate the 3-dimensional configuration of the transverse flagellum. Modifications of previous structural models are proposed.     

THE AUTOFLUORESCENT FLAGELLUM: A NEW PHYLOGENETIC ENIGMA1

Epifluorescence microscopy reveals the presence of fluorescence in the living cells of at least three classes of flagellates. In Ochromonas cells, the fluorescence is blue-green in color and is found only in the short flagellum, both in the flagellar swelling and throughout the length of the flagellum. As recognized by the locale and color of the flagellar fluorescence, the same fluorescence is observed in only certain other heterokont algal groups but is also found in one of the two isokont flagella of the prymnesiophyte Prymnesium parvum.     

PRESENCE OF A SULFATED POLYSACCHARIDE IN THE EXTRACELLULAR MATRIX OF PLATYDORINA CAUDATA (VOLVOCALES,CHLOROPHYTA)1

Evidence for the presence of a sulfated polysaccharide component within the extracellular matrix of Platydorina caudata Kofoid is presented. In situ staining with alcian blue and toluidine blue O indicates accumulation of a sulfated polysaccharide in the matrix. The entire matrix was readily solubilized by a hot aqueous extraction and a sulfated proteoglycan complex was isolated. Thin-layer chromatography of hydrolysates and infrared analysis and chemical desulfation of the intact molecule indicate that the polysaccharide component is principally an arabinogalactan with ester-linked sulfate groups. Protease treatment of the extract revealed two distinct bands separable on cellulose acetate electrophoresis. The slower moving component was a sulfated glycoprotein while the faster moving component was a sulfated mucopolysaccharide essentially free of protein. This is the first report of specific chemical analyses and electrophoretic separation of a sulfated polysaccharide within the matrix of a member of the Volvocales. The cytochemistry and electrophoretic patterns of the P. caudata preparation are compared with the same type of extract made from Chlamydomonas reinhardtii Dang. The possible evolutionary significance of the electrophoretic patterns is presented.     

赖夫生鞭毛染色法的改进

赖夫生染色法是细菌鞭毛染色的一种常用方法,最近发现了延长赖失生染剂使用寿命及改进染色效果的方法,并在此基础上进一步论证了乙醇在染色过程中所起的作用。     

CELL SORTING IN THE PRESENCE OF CYTOCHALASIN B

The ability of cytochalasin B to inhibit ruffled membrane activity and cellular locomotion of vertebrate cells in monolayer culture prompted its use to study the necessity for this kind of active cellular locomotion in cell sorting in heterotypic cell aggregates. Cell sorting was inhibited in chick embryo heart-pigmented retina aggregates but a remarkable degree of sorting did occur in neural retina-pigmented retina aggregates. In these experiments, the levels of cytochalasin B employed (5 or 10 µg/ml) are sufficient to inhibit completely locomotion of these cell types in monolayer culture. It is proposed that the degree of cell movement achieved during sorting in neural retina-pigmented retina aggregates in the presence of cytochalasin B is the result of changes in cell contact resulting from adhesive interaction of cells. The effect of cytochalasin B on the initial aggregation of dissociated cells was also tested. With the cell types used in this study (chick embryo neural retina and limb bud), aggregation was not affected for a period of several hours.