日本血吸虫尾蚴发育的超微结构观察：I.体被局部剖析

本文根据日本血吸虫尾蚴发育分期,除胚细胞（Ｓ１）已有报道（胡敏等,１９９１）外,对胚球期（Ｓ２）、尾蚴雏体期（Ｓ３）、成熟前期（Ｓ４）及成熟期（Ｓ５）在透射电镜对体被及其要素进行剖析。结果原（始）体被最早出现于Ｓ２,表性分布。随后（Ｓ３－Ｓ５）消失而为真正体被所取代。体被皱褶亦随高隆。基膜及体棘为名期基本结构。感觉乳突于Ｓ３、Ｓ４出现。到了Ｓ５渐趋复杂而完善并对其结构作了较精细的描述。糖膜直至成熟     

日本血吸虫尾蚴发育的超微结构观察：Ⅱ.腺体

在透射电镜下观察不同发育期日本血吸虫尾蚴的腺体。结果：胚球期（Ｓ２）主要出现体细胞分裂与分化,首次证明分泌细胞及其小体在Ｓ２出现,雏体期（Ｓ３）见到前钻腺细胞体与钻腺管束及分泌小体。成熟前期（Ｓ４）钻腺分泌小体基质分Ａ／Ｂ为主两型,分别演变为成熟期（Ｓ）５的后／前钻腺分泌小体。头腺分泌小体亦在Ｓ４出现。从前钻腺体排至头器远端腺管的分泌小体,显眼透明球消失成为致密同质性小体,已为大家共识。而在后钻腺     

钉螺体内日本血吸虫尾蚴发育期的形态及其扫描电镜观察

本文通过活体标本、连续切片、全封标本及扫描电镜观察了大陆品系日本血吸虫Schistosomajaponicum子胞蚴体内尾蚴发育期的形态。日本血吸虫尾蚴发育分为五期,即胚细胞期、胚球期、尾蚴雏体期、成熟前期和成熟期。与曼氏血吸虫尾蚴发育进行比较,日本血吸虫尾蚴在胚球期无极化现象;尾蚴雏体期的尾芽形态多非圆球形,尾叉形成较早。钻腺及焰细胞均在此期发生,较曼氏血吸虫尾蚴早。除了上述头器、头腺、钻腺、焰细胞及消化器官进一步发育外,体内散在胚细胞结集为生殖始基,体表感觉乳突分化与体尾肌细胞的发育,尾蚴从成熟前期过渡到成熟期。 电镜首次原位观察尾蚴发育在子胞蚴育腔内的自然状态。尽管偶尔可见到胞蚴体壁与胚元之间某些结构联系,但大部份的胚元各自独立混杂在育腔之中。此外尚注意到尾蚴体棘发生在成熟前期,但其密度较成熟尾蚴小,而其大小却比成熟尾蚴的大。尾蚴头器上感觉乳突和围褶可能先于内部腺体细胞的分化。     

薏苡胚发育及贮藏营养物质积累的研究

薏苡（Ｃｏｉｘ ｌａｃｒｙｍ ａ－ｊｏｂｉ）胚发育分下列各期：棒形胚前的原胚期、棒形胚期、胚芽鞘期、１叶期、２ 叶期、３叶期、４ 叶期、５ 叶期及６叶期成熟胚。３ 叶期胚具１ 条不定根（种子根）,４ 叶期具２ 条,５ 叶期及成熟胚期具３ 条。不定根与胚根排成１ 纵行。营养物质最先在盾片细胞中积累。开花后９ 天的１ 叶期胚,在盾片、胚芽鞘及胚轴细胞中积累了淀粉,以后遍及成熟胚的各部分。淀粉粒含量与器官发生及生长顺序成正相关,但发育后期,盾片细胞内的淀粉粒含量下降。开花后１０ 天,盾片细胞中形成含晶体的蛋白质体,晶体含蛋白质及植酸钙镁。以后,这种蛋白质体增多、增大。同时,又形成不含晶体的蛋白质体。一定时期,含晶体的蛋白质体消失,不含晶体的蛋白质体增多,直到胚成熟。开花后１３ 天,胚芽鞘上部细胞形成蛋白质体。以后遍及成熟胚的各部分,器官发生越早,所含蛋白质体越多、越大。开花后１０ 天,盾片细胞中产生了脂体,成熟胚的盾片细胞,含有大量的脂体。还观察了胚发育各期与颖果及盾片长度的对应关系     

日本血吸虫尾蚴发育的超微结构观察：Ⅲ.肌肉

在超微结构水平对日本血吸虫发育期尾蚴的主要肌肉包括体壁、头器、腹吸盘和尾部等进行观察,首次证明发育期体壁肌层组织最早见于Ｓ２,在原始基膜（ＰＢＬ）下方有１￣２层类似纤丝胞质块,为早期肌细胞管状胞质延伸至原始基膜下的结构,Ｓ３这种现象更为明显;典型体壁外环肌与内纵肌在Ｓ４与Ｓ５已形成。腹吸盘早期原始肌细胞的分化见于Ｓ３,至Ｓ５强大的腹吸盘肌纤维已形成。文章首次提出内间质层在Ｓ３、Ｓ４的体部存在及Ｓ５     

小麦体细胞胚发生的超微结构研究

对小麦（Ｔｒｉｔｉｃｕｍ ａｅｓｔｉｖｕｍ Ｌ．）幼胚培养中体细胞胚发生过程的超微结构变化进行了研究,结果如下：（１）原体细胞中大液泡消失,存在大量小液泡,细胞质的电子密度加强,核大,核仁明显,出现多核仁;（２）细胞器数量和种类,如质体、核糖体和线粒体增加;（３）细胞壁加厚,胞间连丝逐渐消失,细胞器数量丰富,胚性细胞中积累淀粉;（４）细胞壁加厚的胚性细胞中存在核仁液泡、自体吞噬泡和分泌泡;（５）多细胞原胚、球形胚和梨形胚被一层外壁包围,但胚体内细胞间广泛存在胞间连丝;（６）成熟胚生长点部位的细胞内质体中出现膜系结构,已向叶绿体转变,类囊体已形成     

小偃麦部分双二倍体及其异附加系异源染色体的GISH分析

应用ＴＩＳＨ对小偃麦部分双二倍体ＴＡＦ４６（２ｎ＝８ｘ＝５６）及其衍生的６个二体异附加系的中间偃麦草染色体组种类进行了分析、鉴定。以拟鹅冠草（Ｐｓ．ｓｔｒｉｇｏｓａ）ＤＮＡ为探针的分析结果表明,ＴＡＦ４６所含有的中间偃麦草染色体组为合成染色体组,即６条Ｓｔ组染色体和８条Ｅ组染色体。在其衍生的二体异附加系中,Ｌ４和Ｌ７含有Ｓｔ组染色体,Ｌ１、Ｌ２、Ｌ３、Ｌ５含有Ｅ组染色体。ＴＡＦ４６所含有的中间偃麦草染色体的部分同源群依次为ＩＥ（Ｌ３）、２Ｓｔ（Ｌ６）、３Ｅ（Ｌ２）、４Ｓｔ（Ｌ４）、５Ｅ（Ｌ５）、６Ｓｔ（Ｌ７）、７Ｅ（Ｌ１）。     

影响火炬松胚性悬浮细胞原生质体的胚胎发生的因素(英文)

火炬松（ＰｉｎｕｓｔａｅｄａＬ．）是我国亚热带和部分热带地区最重要的绿化和造林树种。它的生长周期长,杂合程度高,难以用常规的杂交方法进行品种改良。建立火炬松的原生质体胚胎发生体系,有可能、进而以遗传转化为基础进行火炬松等针叶树的品种改良。本研究以湖南省绍阳市的火炬松成熟种子为材料,建立胚性细胞悬浮系。将其培养至对数生长期,用１％ＲＳ、２．５％Ｒ１０和０．２％Ｙ２３的酶混和液分离原生质体,活力达９０％以上（Ｆｉｇ．１）。纯化原生质体,在再生培养基上培养２天后,细胞壁再生（Ｆｉｇ．２）;;６天后,６５％的原生质体第１次分裂（Ｆｉｇ．３）;培养３周后,形成小细胞团（Ｆｉｇ．４）;６周后,形成大细胞团（Ｆｉｇ．５）;８周后,形成胚性胚柄细胞团（ＥＳＭ）（Ｆｉｇ．６）;１０周后,形成早期体细胞胚（ＥＳＥ）（Ｆｉｇ．７）;１２周后,形成后期体细胞胚（ＬＳＥ）（Ｆｉｇ．８）火炬松原生质体胚形成过程中的关键结构是ＥＳＭ,ＥＳＥ和ＬＳＥ。它们形成的最佳基本培养基是１．２５ＬＰ培养基。再生培养基中高浓度的ＢＡ和低浓度的肌醇有利于ＥＳＭ的形成,但不利于ＥＳＥ和ＬＳＥ的形成。反之,低浓度的ＢＡ和高浓度的肌醇不利于ＥＳＭ的形成,     

家蚕胚后发育中过氧化氢的代谢及其意义(英文)

活性氧参与生物体内复杂的代谢过程。本文对它在家蚕个体发育过程中的生物学功能进行了初步探讨。 取１岁龄家蚕蛹分别注射Ｈ２Ｏ２、脱皮激素（Ｅｃｄｎ）、保幼激素（ＪＨ）和还原型谷胱苷肽（ＧＳＨ）,培养;定期取样测定家蚕体内Ｈ２Ｏ２含量。 对家蚕整个幼虫期（Ｆｉｇ．１）,尤其是大眠期（Ｆｉｇ．２）、化蛹期（Ｔａｂｌｅ１）、蛹期（Ｆｉｇ．３－ａ,ｂ,ｃ）以及成虫期（Ｆｉｇ．４, Ｔａｂｌｅ ２）的研究结果表明,家蚕体内Ｈ２Ｏ２代谢具有如下特点：（１）入眠、化蛹、化蛾和死亡前Ｈ２Ｏ２含量都显著下降;（２）幼虫期１－３龄Ｈ２Ｏ２含量逐步下降,４～５龄Ｈ２Ｏ２含量回升,蛹期和成虫期Ｈ２Ｏ２含量与４～５龄接近;（３）每个龄期的中期Ｈ２Ｏ２含量最高;（４）ＣＡＴ活性与Ｈ２Ｏ２含量呈负相关变化,前者迟于后者;另外,ＣＡＴ活性远远大于ＳＯＤ活性;（５）Ｅｃｄｎ、ＧＳＨ处理可以降低家蚕蛹期Ｈ２Ｏ２含量,并使其提前下降,ＪＨ、Ｈ２Ｏ２处理含量下降,并相应地提早推迟化蛾;（６）成虫期雄蛾Ｈ２Ｏ２含量、ＳＯＤ和ＣＡＴ活性都显著高于同时期雌蛾。家蚕体内Ｈ２Ｏ２含量的变化与其发育密切相关。Ｈ２Ｏ２含量下降是变态的信号;家蚕成虫期Ｈ２Ｏ２ 在性别上的     

影响木薯次生胚状体发生及植株再生因素的研究

研究了在外植体的不同发育阶段中,碳源以及不同的生长激素配比对木薯次生胚状体诱导及植株再生的影响。结果表明：以固体成熟培养基上生长１５ｄ的胚状体子叶为外植体,次生胚状体的产量最高,达２９．３个成熟胚状体／１个外植体。在次生胚状体的诱导阶段,以麦芽糖（４０ｇ／Ｌ）代替蔗糖作碳源,能同时提高次生胚状体的产量（３２．５个胚次体／１个外植体）及植株再生频率（７４．３％）。２,４－Ｄ与ＰＰ３３３;（０．１ｍｇ／Ｌ）配合能提高植株再生频率到７７．６％。２,４－Ｄ与ＢＡＰ（２ｍｇ／Ｌ）或激动素（２．０ｍｇ／Ｌ）配合则大大降低了胚状体诱导及植株再生频率。     

An ultrastructural study of the early cercarial development in Prosorhynchoides borealis (Digenea: Bucephalidae) with special reference to formation of the primitive epithelium

Primitive epithelium and outer tegumental layer formation during early cercarial development was studied in Prosorhynchoides borealis using electron microscopy. It demonstrated that germinal cells freely floating in the sporocyst body cavity divide to give rise to naked cell aggregates. These early embryos are highly irregular in outline and are composed of blastomeres differing in size and structure. In embryos consisting of about 12-14 cells a few (possibly only two) superficial macromeres become concave and produce thin extensions which envelop the embryonic mass before fusing to form a syncytial primitive epithelium. This primitive epithelium forms syncytial connections with underlying embryonic cells. Primordial tegumental cells become apparent in late germinal balls below the primitive epithelium. These cells expand and fuse to give rise to an embryonic nucleated tegument. The embryonic tegument is connected to peripheral embryonic cells by thin cytoplasmic bridges until the basement lamina is formed. Subsequently, the primitive epithelium is shed by the embryos and the nuclei in the embryonic tegument undergo pyknotic degeneration. These results are analysed and compared with data from studies on other trematode species and it is concluded that the primitive epithelium is derived from the embryo in at least the majority of digeneans.     

Fasciola hepatica: interaction of the tegument with poly-L-lysine and enzymes

The tegument of Fasciola hepatica was treated with 0.5% pepsin (EC 3.4.4.1), 0.5% alpha-amylase (EC 3.2.1.1), and 0.5% sheep bile solutions both without and following preincubation in poly-L-lysine. Without poly-L-lysine preincubation, pepsin appeared to be breaking down limited areas of the tegumental surface but had no other marked effects on tegumental structure. alpha-Amylase and bile had no major effects on the tegument except for a reduction in matrix density by the latter. Incubation in poly-L-lysine alone resulted in some changes in surface morphology of the tegument and a limited amount of swelling of the basal infolds. When poly-L-lysine was followed by pepsin treatment, blebbing, microvillus-formation, and swelling of the basal infolds was greatly enhanced and led to surface destruction in some areas. alpha-Amylase following poly-L-lysine resulted in complete destruction and loss of the tegument, and left the basal lamina as the external surface, Incubation in bile after poly-L-lysine preincubation resulted in little change in tegumental morphology.     

Surface ultrastructure of the developmental stages of Heterophyopsis continua (Trematoda: Heterophyidae).

Ultrastructural observations were made on the tegument of juvenile and adult stages of Heterophyopsis continua using scanning electron microscopy. On the surface posterior to the ventral sucker, the tegumental processes were bandlike in the metacercariae, cobblestonelike in the flukes 2 days postinfection (PI), and velvety at 3 days PI. The anterior surface between the oral and ventral suckers of the metacercariae was packed densely with tegumental spines having a 10- to 14-pointed tip. In flukes 6 days PI, the number of points increased to 15-17. The tegumental spines immediately behind the ventral sucker on the metacercariae surface possessed 5-7 points; posteriorly the points were reduced in size and in number. Ciliate sensory papillae (type I), as single or clumped forms of 2 or 3, were abundant around the oral and ventral suckers of metacercaria and adult worms. The clumped papillae appeared bilaterally symmetrical on the dorsal and ventral surfaces. The ciliate papillae may function in tango-, rheo-, and/or chemoreception. On the lip of the ventral sucker, 6-7 aciliate domed papillae (type II) were arranged in an equidistant manner. At 2 days PI each type II papilla became a clumped form having 2 or 3 papillae. Type II papillae may function as tango- and/or pressure-receptors. The structure and distribution of papillae suggest that the ventral sucker likely functions as a holdfast organ and the oral sucker as a probing organ involved in feeding.     

Ultrastructure of the Tegumental Basement Membrane of Fasciola hepatica(Trematoda)

The fine–structural characteristics of the basement membrane of the tegument of F. hepatica were examined following extraction fixations and tannic acid infiltration. The basement membrane was shown to consist of three layers: lamina lucida, lamina densa, and lamina reticularis. The lamina densa appeared amorphous and homogeneous with tannic acid impregnation. The lamina reticularis appeared as a dense network of 10–12 nm fibrils. Anchoring fibrils cross this layer and form loops. Along their length they contact hemidesmosomes of muscles, thus connecting muscle to muscle and to tegument. The tegument/basement membrane contact is enhanced by extensions of the lamina densa into infoldings of the tegumental basal membrane. Where tegumental spines reach the basement membrane, the contact is reinforced by hemidesmosomes that connect to anchoring fibrils reaching toward the underlying muscles. The basement membrane thus seems to be a complex structure integrating the distal tegumental layer with underlying tissues and transducing muscle contractions to the tegument and its spines.     

Fine structure of the germinal membrane of Echinococcus granulosus cysts.

The ultrastructure of the hydatid cyst germinal membrane was studied. It was divided into 3 regions, the tegument, the tegumental cell region, and the innermost area bordering the cyst cavity. The morphology of tegumental, muscular, flame, duct, and glycogen-containing cells and cells containing lysosomal-like bodies is described. The significance of these findings is discussed in terms of the possible function of these structures and present knowledge on the penetration of macromolecules into hydatid cysts.     

Schistosoma haematobium: Amoscanate and adult worm ultrastructure

Amoscanate, when administered orally as an aqueous or “formulated” preparation, induced pronounced ultrastructural abnormalities in male and female Schistosoma haematobium. Higher dose levels of the aqueous suspension (300 mg/kg body wt) had to be administered to achieve the full range of effects induced by formulated doses of 2.5–8 mg/kg body wt. Worms were recovered from hamsters between 1 and 120 hr after treatment. Although the amount of amoscanate-induced damage varied considerably between worms, an overall pattern of damage emerged. Initially, 1 hr after treatment, amoscanate caused tegumental vacuolation and oedema. As the drug treatment period was extended to 24 hr, blebbing, exudation, collapse of sensory organelle bases, and abnormal mitochondria became increasingly evident. With exposure to higher drug doses (50–300 mg/kg body wt), the tegument became further distorted with the appearance of necrotic structures and myelin whorls, which appeared to represent various stages in lysosomal formation and digestion. Eventually, erosion of surface layers resulted in the breakdown of tegumental integrity. The caeca and vitellaria were also adversely affected by drug treatment. Basal vacuolation and the formation of myelin whorls occurred in the gastrodermis. In the mature S4 vitelline cells, coalesced vitelline droplets and myelin whorls were evident.     

Effects of praziquantel and artesunate on the tegument of adult Schistosoma mekongi harboured in mice

The effects of praziquantel and artesunate on the tegument of adult Schistosoma mekongi harboured in mice were compared using scanning electron microscopy (SEM). Forty-two mice infected with S. mekongi for 49 days were treated intragastrically with either 300 mg/kg praziquantel or 300 mg/kg artesunate. Mice were sacrificed 1 or 3 days post-treatment. Worms were collected by perfusion and examined by SEM. One to 3 days after administration of artesunate, the tegument of S. mekongi showed severe swelling, vacuolization, fusion of the tegumental ridges and loss or shortening of the spines on the trabeculae, collapse and peeling. Praziquantel induced similar tegumental alterations as those observed after administration of artesunate, but they were less severe. Three days post-treatment, there was evidence of recovery only in the case of praziquantel. The results of our study suggest that artesunate is more effective than praziquantel in causing tegumental damage in adult S. mekongi, and provides a basis for subsequent clinical trials.     

Sparganum proliferum: an overview of its structure and ultrastructure.

A detailed study of the structure and ultrastructure of Sparganum proliferum was made possible for the first time thanks to the successful in vitro and in vivo maintenance of this rare parasite. Although S. proliferum exhibits many of the classical tegumental and parenchymal structures previously described for other larval cestodes, these are either arranged in a distinct fashion or, in some cases, may be completely different. Among the latter and of special interest are the single or multiple parenchymal cavities, surrounded by tegument, which in some instances appear to act as a primitive digestive tract.