中华绒螯蟹蜕壳过程中肌肉的组织学、超微结构及主要蛋白质含量的变化

为探讨中华绒螯蟹(Eriocheir sinensis)蜕壳前后肌肉组织的形态特征变化, 采用石蜡切片、电镜及生物化学方法, 研究了中华绒螯蟹蜕皮过程中步行足和腹部肌肉的组织学、超微结构及主要蛋白质含量的变化。结果显示: 相对于蜕皮间期, 步行足在蜕皮前后组织学形态特征无明显变化; 超微结构在蜕皮前无明显变化, 蜕皮后可见肌原纤维纵裂及肌小节横裂现象, 表明蜕皮后外骨骼硬化的过程伴随着肌肉的生长。相对于蜕皮间期, 腹部肌肉在蜕皮前后组织学特征变化明显: 蜕皮前肌束间隙增大, 蜕皮后肌束内肌纤维间隙增大。电子显微镜观察显示, 蜕皮前肌原纤维在内部降解, 出现空洞, 肌原纤维边缘降解, 导致肌原纤维间隙增大; 蜕皮后肌原纤维重新组装、重建, 恢复到间期正常形态。生物化学研究发现, 蜕皮前后步行足和腹部肌肉中肌原纤维蛋白和可溶性蛋白含量的变化同其结构特征的变化相一致。以上研究结果表明, 中华绒螯蟹肌肉组织的结构特征同蜕皮周期密切相关。     

一种特殊的长寿细胞:毛竹茎秆纤维细胞

利用显微和细胞化学方法,对毛竹(Phyllostachys edulis)茎秆纤维次生壁形成过程中超微结构变化以及ATP酶、Ca2 -ATPase和酸性磷酸酶的超微细胞化学定位进行了研究.研究发现,次生壁形成早期,细胞核具有双层核膜,染色质凝聚,可见大量的线粒体、粗面内质网和高尔基体等细胞器存在于纤维细胞中;随后,双层核膜消失,细胞器将逐渐解体,多泡体开始出现在纤维细胞的细胞质;随着年龄的增加,纤维细胞壁逐渐增厚,并出现多层结构现象,而运输小泡、细胞膜、胞间连丝和凝聚的染色质将持续存在.在次生壁形成的整个过程中,ATP酶、Ca2 -ATPase和酸性磷酸酶在运输小泡、细胞膜、质膜内陷、胞间连丝和凝聚的染色质中将持续存在.结果表明,毛竹茎秆纤维细胞是一种不同于木本双子叶植物的长寿细胞,纤维原生质体中ATP酶和酸性磷酸酶的持续存在与次生壁的持续增厚密切相关.     

Le Système Nerveux des Cténaires

Summary A subectodermal nerve-net is demonstrated in ten species of Ctenophores by means of either Methylene Blue vital staining or silver impregnation. There is no evidence of subendodermal nerve-net. The ectodermal nerve-net displays a characteristic polygonal pattern which is thought to result from morphogenetic events. Both bipolar and tripolar neurones occur.Three types of concentrations of nervous tissue are described: a) a high accumulation of nervous perikarya at the aboral sensory pole; b) a noticeable densification of the net along the eight meridional ciliary strands of every species, and around the lips of Beroidea; c) in the Cydippids Pleurobrachia and Hormiphora two thick strands of fibers and neurones interconnecting the aboral organ and the tentacles: the tentacular nerves.Ultrastructural evidence is given for the presence of nervous elements under and amidst ectodermal epithelial cells. Three features allow the recognition and characterization of neurites and neurones: a) numerous clear and/or granulated vesicles; b) microtubules in variable amounts; c) frequent and highly differentiated synaptic contacts.The very peculiar arrangement of the presynaptic elements is observed in all the species of Ctenophores so far studied. These synaptic contacts suggest chemical transmission in the nerve-net.On the basis of ultrastructural evidence the author refutes the nervous nature previously attributed to the ciliated cells of the meridional grooves.A parallel is drawn between nervous systems of Cnidaria and Ctenophora.

Ce travail correspond à la première partie d'une thèse de Doctorat d'Etat, intitulée: «Système nerveux et intégration chez les Cténaires». Il a été effectué au sein de l'Equipe de Recherches Associée au C.N.R.S. n^o 183 (Directeur: Dr. Max Pavans de Ceccatty) et avec le concours du Centre de Microscopie Electronique Appliquée à la Biologie, de l'Université Claude Bernard.Ce travail a bénéficié de la collaboration technique de Madame J. Amsellem que nous remercions vivement.     

The effect of starvation on the ultrastructure of the red and white myotomal muscles of the crucian carp (Carassius carassius)

Summary The effect of 16 weeks total starvation on the ultrastructure of the red and white myotomal muscles of the crucian carp (Carassius Carassius) has been investigated. In the white fibres the amount of myofibrillar material fell from 89.6% to 70.7% of the total fibre volume whilst in the red fibres the fall was from 72.2% to 70.3%. The sarcoplasmic reticulum appeared to have become swollen during starvation in both fibre types. In the white fibres the terminal cisternae of some triads seem to have fused. The volume of the red fibres occupied by mitochondria was reduced from 16.2 % to 5.9 %. The concentration of mitochondria in the white fibres was too low to detect any quantitative changes. A marked reduction in the amount of euchromatin material was observed in most white fibre nuclei and many red fibre nuclei. Many of the ultrastructural changes noted in the present study can be correlated with biochemical changes known to occur in the red and white myotomal muscles of fish during starvation. This work was supported by a grant from the Natural Environmental Research Council.     

Ultrastructure de l'endomètre humain normal

Résumé L'ultrastructure générale des cellules K endométriales est semblable chez l'Homme, le Rat et le Singe. Mais les granulations des cellules K humaines sont plus variées que dans ces deux dernières espèces et ont certains aspects suggérant une fonction catabolique.Etant donné cet aspect catabolique et l'existence connue d'une activité phosphatasique acide de ces cellules contenant de la relaxine, les auteurs suggèrent que les cellules K pourraient être des cellules sécrétantes en involution et ques les cellules sécrétant activement la relaxine pourraient avoir un aspect morphologique quelque peu différent de celui des cellules K.

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Ultrastructure of the normal human endometriumIII. The endometrial granular stroma cells

Summary The general ultrastructure of endometrial granular stroma cells is similar in man, rat, and monkey. But the granulations of human granular stroma cells are more various than in these two last species and have some aspects suggesting a catabolic function.With respect to this catabolic aspect and the previously shown acid-phosphatase activity of these relaxin-containing cells the authors suggest that the granular stroma cells could be involutive secretory cells and that the active relaxin-secretory cells may have some different morphological aspect.

     

Structure and innervation of the pineal gland of the rabbit,Oryctolagus cuniculus (L.)

Summary A light microscopic investigation of the rabbit pineal gland with the aid of silver-stained sections gave the following results. In the gland a medulla and a cortex can be distinguished, the medulla containing so-called light and dark pinealocytes, the cortex only light ones. Autonomic nerve fibres reach the pineal organ by two routes: (1) via the perivascular spaces of pineal blood vessels and (2) via two distinct nerve bundles, the nervi conarii. Bilateral superior cervical ganglionectomy revealed that these pinealo-petal nerve fibres are mainly orthosympathetic postganglionic. Intramural pineal neurones with synaptic-like structures on their cell bodies and dendrites point to the presence of a parasympathetic innervation next to the orthosympathetic one. Direct afferent or efferent neural connections with the brain appeared to be absent. Acknowledgements. The author wishes to thank Professor Dr. J. Ariëns Kappers for encouragement and help, Mr. H. K. Koerten for his technical assistance and Miss A. M. Feddema for typing the manuscipt.     

Electron microscopical studies ofThorea ramosissima (Thoreaceae,Rhodophyta): Taxonomic implications ofThorea pit plug ultrastructure

The thallus ofThorea ramosissima was studied electron microscopically. The cells of the medulla, the cortex and the assimilatory hairs differ not only in size and number of plastids and their equipment with thylakoids but also in cell wall structure, the number of mitochondria and the activity of the Golgi apparatus, with dictyosomes transforming complete cisternae into Golgi vesicles with mucilaginous contents in the outer region of the cortex. The pit connections have plugs with a distinct plate—like (not dome-like) outer cap layer. BecauseT. riekei was reported to have dome-like outer cap layers and because this character was the main reason to place theThoreaceae into theBatrachospermales (Pueschel & Cole 1982),T. riekei was reinvestigated, too. A distinct outer cap could not be detected. The reliability of pit plug structure as a taxonomic character and the taxonomic position ofThorea is discussed.     

玉米叶片主脉及其鞘组织的早期发育和超微结构

研究了玉米叶片中层基本分生组织３个相邻细胞形成主脉原形成层及维管束鞘（ＢＳ）的早期发育过程和超微结构。结果表明，在由３个相邻细胞组成的３－细胞单元中，位于中间的细胞发生２次平周分裂，产生１个较小的和１个较大的细胞，前者分化为近轴端ＢＳ细胞前体，后者再发生１次不均等平周分裂产生１个远轴端ＢＳ细胞前体和１个原形成层起始细胞；位于两侧的细胞其中有１个也发生１次平周分裂，所产生的２个子细胞与另１个侧向细胞     

黄芩甙对肝癌细胞BEL-7402形态学的影响

目的观察黄芩甙对肝癌细胞BEL-7402凋亡的影响，同时观察对肝癌细胞形态及超微结构、线粒体超微结构、线粒体膜电位和细胞内Ca^2＋的影响，探讨线粒体损伤在黄芩甙诱导肝癌细胞凋亡中的作用及可能的机制。方法应用细胞培养技术培养肝癌细胞BEL-7402，光镜、倒置显微镜、扫描电镜、透射电镜观察细胞形态及超微结构的变化尤其是线粒体的变化，应用流式细胞仪检测细胞凋亡百分率及线粒体膜电位、细胞内Ca^2＋的改变，免疫组化法检测细胞Bcl-2、Pax蛋白表达。结果黄芩甙诱导肝癌细胞BEL-7402凋亡呈剂量依赖关系，细胞形态、超微结构及线粒体超微结构出现明显改变，降低肝癌细胞线粒体膜电位，使细胞内Ca^2＋增加，细胞Pax表达增加，广泛分布于胞核和胞质中，Bcl-2表达减少。结论黄芩甙诱导肝癌细胞BEL-7402凋亡，线粒体损伤在黄芩甙诱导肝癌细胞凋亡中起重要作用，其机制可能为抑制肝癌细胞Bcl-2蛋白表达，促进Pax蛋白表达及细胞内Ca^2＋增加，激发线粒体膜通透性转运孔开放，线粒体跨膜电位降低，使肝癌细胞凋亡。     

Plasticity of gonad development in hermaphroditic sparids: ovotestis ontogeny in a protandric species,Lithognathus mormyrus

Synopsis Heterosexual gonad development in a sparid species, Lithognathus mormyrus, was studied by histological and cytological examination, during the first three years of life. Gonad bisexuality is achieved after two months of development, according to the cytological dynamics known in sparids. In one-year-old fishes, a variability in the gonad morphology of the juvenile is shown: three different types of ovotestis have been identified within the same cohort: ovotestes with testicular prevalence (25%), testicular and ovarian equivalence (20%), and ovarian prevalence (55%). This morphological variability of the juvenille ovotestes was consistent with the histological analysis of the sexual structure of the adult stock at the first sexual maturity, which constituted 55.5% of functional males (stemming from the first types of ovotestis) and 44.5% of primary females (from the third type). The plasticity of sexual expression in sparids is emphasized, revealing the potentialities of the ovotestis.