ELECTRON MICROSCOPIC STUDIES OF EXTRAPLASTIDIC ASTAXANTHIN IN HAEMATOCOCCUS12

The ketonic carotenoid astaxanthin accumulates in perinuclear cytoplasm characterized by a network of ribosome-coated endoplnsmic reticulum segments, free ribosomes, dictyosomes in active stages of vesicle formation, and mitochondria. The pigment granules form in the ground substance and not within any organelle or vesicle. Coalescence of the globular granules results from increasing quantities of astaxanthin formed as the cells age. The gross differences in fixation image following glzitaraldehyde-KMnO₄ and glutaraldehyde-O_sO₄ are illustrated, and the need for n variety of fixations upon which interpretations are bused is emphasized. The bright red coloration of akinetes is due to a masking of the chlorophyll by the massive astaxnnthin deposits rather than m y break-down of the chloroplast thylakoids.     

ELECTRON MICROSCOPIC STUDIES OF INDUCED CARTILAGE DEVELOPMENT AND CALCIFICATION

Cultured, human, amniotic cells (FL strain) injected into the thigh muscles of cortisone-conditioned mice proliferated to form discrete colonies which, over a period of 5 days, became invested by numerous fibroblasts. Cartilage cells and matrix appeared within the fibroblastic zones during the succeeding 2–4 days. Cartilage matrix calcified within 12 days following FL-cell injection. Cartilage cells closely resembled fibroblasts from which they appeared to be derived, and were readily distinguished from FL cells by their prominent ergastoplasm and Golgi complexes. Cartilage matrix was composed of a distinctive feltwork of randomly arranged, collagen fibrils (~600 A axial period and ~250 A width) from which small electron-opaque, leaflike matrix particles extended. Matrix calcification occurred with the deposition of radially arranged needle-like structures resembling hydroxyapatite. Dense centers were often identified within these clusters. Examination of heavily calcified areas revealed confluent masses of apatite-like material. In general, the fine structure of induced cartilage formation and calcification resembled that of cartilage development and calcification as previously described in the normal epiphysis.     

革蜱未成熟期哈氏器的扫描电镜研究

用扫描电镜观察了革蜱属8种幼虫和若虫的哈氏器,并与其他属5种幼虫和4种若虫的哈氏器进行比较,以阐明其形态特征及其在分类中的意义。其中,9种幼虫和8种若虫哈氏器的结构是首次报道。革蜱属幼期哈氏器的囊孔形状、前窝感毛数目及其中孔毛的位置等与其他属不同。东洋区的金泽革蜱与古北区的革蜱种类之间,在孔毛形状、位置和幼虫近端缝孔的位置上有明显差别。而后者中,阿坝革蜱幼虫一般无近端缝孔;网纹革蜱幼虫和若虫的囊孔形状和幼虫的近端缝孔的位置与其他种类不同。但其余几种革蜱幼虫和若虫的哈氏器无显著差别。     

革蜱成虫哈氏器的扫描电镜观察

本文报道了用扫描电镜观察革蜱属8种成虫的哈氏器.其中三种成虫(阿坝革蜱D. ahaensis、金泽革蜱D. auratus和中华革蜱D. sinicus)的哈氏器结构是首次报道,并与其他属6种成虫的哈氏器进行了比较,以阐明其形态特征及其在分类中的意义.另外,还将这14种成虫哈氏器与各自未成熟期的哈氏器进行了比较.分析和讨论了同种不同时期哈氏器结构的异同.东洋区的金泽革蜱和古北区的革蜱种类间,在孔毛形状,位置及基盘数目上有明显差别,而后者中,边缘革蜱D. marginatus的孔毛位于近端外侧,草原革蜱D. nuttalli和网纹革蜱D. reticulatus的孔毛位于远瑞外侧,其余种类无明显差别.     

周期型马来丝虫成虫和第三期幼虫扫描电镜的观察

近年来,不少学者应用扫描电镜观察恶丝虫(Wong和Brummer,1978)、盘尾丝虫(Franz,1980;Franz和Renz,1980)、彭亨丝虫(Aoki et al., 1980)、成虫和/或童虫、幼虫、亚周期型马来丝虫(Franz,1982)和周期型马来丝虫(程富川等,1982)成虫的形态。我们在1978年成功地用周期型马来丝虫感染长爪沙鼠之后,应用扫描电镜观察马来丝虫成虫和第三期幼虫的形态。现将结果报告如后。     

ELECTRON MICROSCOPIC STUDIES OF MITOSIS IN AMEBAE : I. Amoeba proteus

Individual organisms of Amoeba proteus have been fixed in buffered osmium tetroxide in either 0.9 per cent NaCl or 0.01 per cent CaCl₂, sectioned, and studied in the electron microscope in interphase and in several stages of mitosis. The helices typical of interphase nuclei do not coexist with condensed chromatin and thus either represent a DNA configuration unique to interphase or are not DNA at all. The membranes of the complex nuclear envelope are present in all stages observed but are discontinuous in metaphase. The inner, thick, honeycomb layer of the nuclear envelope disappears during prophase, reappearing after telophase when nuclear reconstruction is in progress. Nucleoli decrease in size and number during prophase and re-form during telophase in association with the chromatin network. In the early reconstruction nucleus, the nucleolar material forms into thin, sheet-like configurations which are closely associated with small amounts of chromatin and are closely applied to the inner, partially formed layer of the nuclear envelope. It is proposed that nucleolar material is implicated in the formation of the inner layer of the envelope and that there is a configuration of nucleolar material peculiar to this time. The plasmalemma is partially denuded of its fringe-like material during division.     

紫彩血蛤鳃的组织化学和扫描电镜研究

紫彩血蛤（Ｎｕｔｔａｌｌｉａｏｌｉｖａｃｅａ）的鳃上皮细胞核多为椭圆形,核内染色体呈丝状;结缔组织细胞的核多为圆形,部分核内有块状Ｆｅｕｌｇｅｎ阳性颗粒,ＲＮＡ在鳃丝上皮细胞最丰富,有的形成直径０．５２μｍ的颗粒,结缔组织和鳃丝上皮细胞内均有直径０．６３μｍ左右的ＰＡＳ阳性颗粒,吞噬细胞呈极强的ＡＮＡＥ阳性,鳃丝上皮细胞呈较弱的阳性。ＡＣＰ和ＡＫＰ在吞噬细胞和外缘上皮细胞中的活性较强,其它部位较弱     

ELECTRON MICROSCOPIC STUDIES ON THE DEVELOPMENT OF VESICULAR STOMATITIS VIRUS IN KB CELLS

The development of vesicular stomatitis virus in KB cells was studied by electron microscopy. Sections of infected cells were made 1, 4, 7, 10, and 20 hours after inoculation of the cell cultures, and at the same intervals the supernatant fluid was assayed for virus titer by the plaque test in chick embryo cells. At 10, 14, and 20 hours after inoculation, virus rods were observed attached to cytoplasmic membranes, inside cytoplasmic vacuoles, and attached to the membranes delimiting these vacuoles; they were also found on the surface membrane of the cells. Besides the rods, spherical particles of different sizes and shapes were seen. The possibility that these structures are related to the development of virus rods is discussed. A similarity was noted between the site of maturation of vesicular stomatitis virus rods and that of some other arbor viruses.     

银合欢根瘤细胞的光学显微镜和电子显微镜研究

银合欢接种根瘤菌形成根瘤后,应用光镜和电镜技术观察。银合欢根瘤由分生组织细胞、皮层组织细胞、维管束系统和侵染细胞区域四个不同部分组成。根瘤菌借助于侵染线侵染细胞,释放进入宿主细胞质中,转变成固氮类菌体。最初每个包被膜内只含单独的类菌体,随后较老的侵染细胞中,每个包被膜内含有一个以上的类菌体。因此,成熟根瘤的侵染细胞可见有2~5个类菌体群集包被膜里,并且明显地累积PHB物质,显示电子染色透明颗粒。本文还讨论了上述变化的意义与银合欢根瘤细胞结构和功能的关系。     

中华蜜蜂工蜂触角感受器的扫描电镜观察

对中华蜜蜂(Apis cerana)工蜂触角感受器的扫描电镜观察,见到在触角上有九种类型的感受器,它们是板形感器、腔锥感器、坛形感器、钟形感器、锥形感器、毛形感器A、毛形感器B、毛形感器C和D、缘感器以及各种类型的刚毛等.对于这些感受器的外部形态和分布部位进行了详细地观察和描述,发现中华蜜蜂与西方意蜂(Apis mellifera)有差异.     

ELECTRON MICROSCOPIC RADIOAUTOGRAPHIC STUDIES OF THE CAROTID BODY FOLLOWING INJECTIONS OF LABELED BIOGENIC AMINE PRECURSORS

Adult Syrian hamsters were given a subcutaneous injection of reserpine 3 days before an intraperitoneal injection of ³H-3,4 dihydroxyphenylalanine or ³H-5, hydroxytryptophan and the carotid bodies were subsequently prepared for electron microscopic radioautography. Other Syrian hamsters were given a subcutaneous injection of reserpine and the carotid bodies were subjected to a sensitive cytochemical test for the detection of unsubstituted amines. These studies were made to determine whether the labeled amine precursors were incorporated into the cells and to see whether the parenchymal cells were affected by reserpine treatment. Material from hamsters treated first with reserpine and subsequently injected with ³H-3,4 dihydroxyphenylalanine or ³H-5, hydroxytryptophan exhibited reduced grains of silver over the cells which were associated mainly with the dense cores of the cytoplasmic granules. These studies offer evidence that the granules of the carotid body incorporate catecholamine and indolamine precursors. Material from hamsters incubated for the presence of unsubstituted amines gave a positive reaction (opaque cytoplasmic granules) for catecholamines but not for indolamines. The latter substances may not be present in quantities sufficient to register a positive reaction in the cytochemical test. The opaque granules, indicative of the presence of catecholamines, decreased in density after reserpine treatment. 5 days after one reserpine injection the granules had regained opacity and were comparable to those seen in the control cells.     

LIGHT AND SCANNING ELECTRON MICROSCOPIC STUDIES ON POLLEN OF TETRAPLASANDRA (ARALIACEAE) AND RELATIVES

Pollen of seven species in Tetraplasandra and three species in related genera were studied with light and scanning electron microscopes. A new thin-section technique was employed for the study of exine stratification and apertural structure. This study reveals several previously undescribed pollen structures for the group. Trends toward increase in pollen size and in specialization of other pollen characters are evident in Tetraplasandra. Pollen of Reynoldsia and Peekeliopanax differs from Tetraplasandra in the pertectate sexine and the absence of inner nexinous breaks, respectively. A pollen correlation study shows that Munroidendron falls readily within the genus Tetraplasandra but is distinguishable from the latter by its bifurcate colpi.     

ELECTRON MICROSCOPIC STUDIES ON THE BEHAVIOR OF GLYCOGEN PARTICLES DURING OOGENESIS IN THE SEA URCHIN

The behavior of glycogen particles during oogenesis in the sea urchin was studied by electron microscopy. Before the beginning of oogenesis the nurse cells include many glycogen particles, which are spherical or multiangular in shape and about 600 A in diameter, lying within the vesicle of the large granules and also in the cytoplasm among the granules. There are few glycogen particles in the spaces among the oocytes and the nurse cells. At the early stage of oogenesis the limiting membrane of the large granule breaks locally and the glycogen particles in the vesicle are dispersed into the cytoplasm. The plasma membrane of the nurse cell also breaks in places and glycogen particles are spread throughout the intercellular space. At the beginning of vitellogenesis, β-pinosomes begin to be formed at the periphery of the oocyte; these take in glycogen particles from the outside which are progressively broken into smaller units.     

ELECTRON MICROSCOPIC STUDIES OF MITOSIS IN AMEBAE : II. The Giant Ameba Pelomyxa carolinensis

Dividing nuclei from the giant ameba Pelomyxa carolinensis were fixed in osmium tetroxide solutions buffered with veronal acetate to pH 8.0. If divalent cations (0.002 M calcium, magnesium, or strontium as chlorides) were added to the fixation solution, fibrils that are 14 mµ in diameter and have a dense cortex are observed in the spindle. If the divalent ions were omitted, oriented particles of smaller size are present and fibrils are not obvious. The stages of mitosis were observed and spindle components compared. Fibrils fixed in the presence of calcium ions are not so well defined in early metaphase as later, but otherwise have the same diameter in the late metaphase, anaphase, and early telophase. Fibrils are surrounded by clouds of fine material except in early telophase, when they are formed into tight bundles lying in the cytoplasm unattached to nuclei. Metaphase and anaphase fibrils fixed without calcium ions are less well defined and are not observably different from each other. The observations are consistent with the concept that spindle fibrils are composed of polymerized, oriented protein molecules that are in equilibrium with and bathed in non-oriented molecules of the same protein. Partially formed spindle fibrils and ribosome-like particles were observed in the mixoplasm when the nuclear envelope had only small discontinuities. Remnants of the envelope are visible throughout division and are probably incorporated into the new envelope in the telophase. Ribosome-like particles are numerous in the metaphase and anaphase spindle but are not seen in the telophase nucleus, once the envelope is reestablished, or in the interphase nucleus.     

ELECTRON MICROSCOPY OF THE AVIAN RENAL GLOMERULUS

Electron microscopy of sections of chicken glomeruli shows them to possess a large central cell mass, occupying the hilum and the centre of the glomerulus, and continuous with the adventitia of the afferent and efferent arterioles. The glomerular capillaries form a much simpler system than in mammals and are spread over the surface of the central cell mass. Between the capillaries the mass is limited externally by the major component of the glomerular capillary basement membrane, which continues over the surface of the mass from one capillary to the next. Projections of the central cell mass characteristically form the support for glomerular capillaries, and smaller knobs of the central mass may project actually into the lumen of the capillaries, but always carry a layer of endothelial cytoplasm before them. They are never in direct contact with blood. The basement membrane of the glomerular capillary loop has a central dense layer and two lateral less dense layers as in mammals. The central dense layer is continuous with similar appearing dense material in the intercellular spaces of the adventitiae of the arterioles, and also with that of the central cell mass. The two less dense layers can also be traced into direct continuity with the less dense regions of this intercellular substance. The endothelial cytoplasm is spread as a thin sheet over the inner surface of the capillary basement membrane, and shows scattered "pores" resembling those described in mammals. Epithelial cells with interlacing pedicels are at least as prominent as those in mammals. Bowman's capsular membrane also possesses three layers similar to but less wide than those of the capillary basement membrane, and all three layers can be traced into continuity with the dark and light regions of the intercellular material of the adventitial cells of the arterioles, and beyond them with that of the central cell mass. At the hilum Bowman's capsular membrane also fuses with the capillary basement membrane.