Immunoelectron microscopical detection of tubulins during spermiogenesis in phytophagous bugs (Hemiptera: Pentatomidae)

Summary

Ultrastructural and immunocytochemical studies were carried out in the tail region of spermatids and spermatozoa of the phytophagous bugs, Acrosternum aseadum and Euchistus heros. The axoneme presented a 9+9+2 microtubule pattern and bridges occurred between axonemal microtubules 1, 5, and mitochondrial derivatives. Two paracrystalline structures, embedded in an amorphous matrix, were observed in the mitochondrial derivatives. The axonemal microtubules contained alpha, acetylated and tyrosinated tubulin. Cytoplasmic microtubules contained alpha, beta and gamma tubulin. Moreover, the gamma tubulin was detected near the electron dense rod, an element associated with the centriole, suggesting that this structure may be a microtubule organizing center.     

Absence of wing polymorphism in the arboreal, phytophagous species of some taxa of temperate Hemiptera: an hypothesis

ABSTRACT.

• 1 Most arboreal Cicadellidae (Homoptera) and the arboreal, phytophagous Heteroptera are macropterous and capable of flight.
• 2 The low incidence of flightless morphs in the above insects is compared with its frequency in the species living on low vegetation.
• 3 It is suggested that in spite of the permanence of arboreal habitats, the almost complete absence of flightless morphs in these groups of the temperate Hemiptera is related to the architectural complexity of trees.

     

聚对苯二甲酸乙二醇酯水解酶检测方法的研究进展

聚对苯二甲酸乙二醇酯(polyethylene terephthalate,PET)是应用最广泛的合成聚酯之一。由于PET不易降解,在环境中积累,对陆地、水生生态系统以及人类健康构成严重威胁。基于生物酶催化的生物降解策略为PET回收利用提供了一种绿色途径,在过去20年间,已发现了多种PET水解酶,并通过蛋白质工程等手段来改善这些酶的降解性能,但是目前仍未找到适合大规模工业应用的PET水解酶。利用传统的检测方法筛选PET水解酶是一个缓慢而复杂的过程。为了促进PET酶法回收的工业化应用,需要研发高效的检测方法。近年来,研究人员开发了多种表征PET水解酶的分析方法。本文总结了可用于筛选PET水解酶的检测方法,如高效液相色谱法、紫外吸光度法和荧光激活液滴分选法等,并对其在筛选PET水解酶的应用方面进行了展望。     

Electrophoretic methods for differentiating glycolytic enzymes of mouse and human origin

Summary Methods for electrophoresis and specific staining of all of the enzymes of the glycolytic pathway are illustrated. Interspecies differences between the enzymes of moue and of human origin are readily demonstrated and are applicable to studies, in mouse-human hybrid cell clones, of linkage, chromosomal assignment, and regulation of the gene loci controlling glycolytic enzymes This study was supported by Grants 1-F03-HD 43122-01 and GM 15253 from the National Institutes of Health.     

Molecular cloning of cDNAs encoding a range of digestive enzymes from a phytophagous beetle, Phaedon cochleariae

To gain better knowledge of the variety of digestive enzymes in phytophagous coleopteran pests, a sequencing screen of 76 random cDNAs from a gut library from Phaedon cochleariae larvae was performed. The screen yielded 21 cDNAs encoding amino-acid sequences homologous to known digestive enzymes, most of them were cell wall-hydrolysing enzymes. The deduced protein sequences of 7 cDNAs encoding putative -amylase, cysteine proteinase, trypsin, chymotrypsin, cellulase, pectinase and xylanase display all the structural features that characterize these enzymes in other eukaryotic organisms. Except the -amylase and chymotrypsin cDNAs, the other cDNAs probably derive from multigene families. The distribution of the corresponding enzymatic activities at various developmental stages of P. cochleariae was examined. -amylase activity is present in guts of larvae and adults, proteinases are abundant in guts of larvae and adults, but scarce in eggs and larval carcasses, xylanases are present in the guts of larvae and adults, as well as in carcasses of larvae, whereas cellulase and pectinase activities are distributed in larval and adult guts, larval carcasses, and eggs. Only a minor fraction of the cellulases is secreted by microorganisms, suggesting that P. cochleariae synthesizes most of its own cell-wall hydrolysing enzymes. The physiological role of the enzymes is discussed, as well as the significance of these results for pest management strategies involving transgenic plants expressing enzyme inhibitors.     

Salivary digestive enzymes of the wheat bug, Eurygaster integriceps (Insecta: Hemiptera: Scutelleridae)

The digestive enzymes from salivary gland complexes (SGC) of Eurygaster integriceps, and their response to starvation and feeding were studied. Moreover, digestive amylases were partially purified and characterized by ammonium sulfate precipitation and gel filtration chromatography. The SGC are composed of two sections, the principal glands and accessory glands. The principal glands are further divided into the anterior lobes and posterior lobes. The SGC main enzyme was α-amylase, which hydrolyzed starch better than glycogen. The other carbohydrases were also present in the SGC complexes. Enzymatic activities toward mannose (α/β-mannosidases) were little in comparison to activities against glucose (α/β-glucosidases) and galactose (α/β-galactosidases), the latter being the greatest. Acid phosphatase showed higher activity than alkaline phosphatase. There was no measurable activity for lipase and aminopeptidase. Proteolytic activity was detected against general and specific protease substrates. Activities of all enzymes were increased in response to feeding in comparison to starved insects, revealing their induction and secretion in response to feeding pulse. The SGC amylases eluted in four major peaks and post-electrophoretic detection of the α-amylases demonstrated the existence of at least five isoamylases in the SGC. The physiological implication of these findings in pre-oral digestion of E. integriceps is discussed.     

The salivary gland secretions of a neotropical bumblebee

Summary The larval salivary gland secretions ofBombus atratus were studied with cytochemical and cytophysical methods. In the young feeding larvae a proteic filamentous secretion depicting striations perpendicular to the long axis of its fibrillary threads and exhibiting a wellordered macromolecular array was found. It appears not to differ from the silk secretion described for the fully grown larvae of an europeanBombus species. However, in the fully grown larvae ofB. atratus changes which have not yet been reported for other bees occur involving the salivary gland secretion. Two secretion types are then distinguishable. One is composed of carboxylated and sulfated acid glycosaminoglycans and glycoprotein(s) (mucous secretion), and the other has the same composition as that of the filamentous secretion of the young larvae, although differing morphologically and in terms of macromolecular alignment (flocculent secretion). The filamentous secretion is assumed to be involved inB. atratus with the spinning of the silken partitions which at a relatively early stage separate the larvae reared within a common cell from one another. The mucous and flocculent secretions will participate in the cocoons which will cover the pupating larvae. The filamentous and flocculent secretions appear to contain an -helical fibroin, glycoprotein(s) and lipoprotein(s), but not collagen-type proteins.     

Fine structure of the salivary glands of Triatoma infestans (Hemiptera: Reduviidae)

The fine structure of the salivary glands of adult Triatoma infestans (Hemiptera: Reduviidae) bugs has been analyzed. Stereomicroscopy and scanning electron microscopy showed that each insect presents a pair of salivary glands, each pair containing three distinct units (main, supplementary, and accessory) with different sizes and colors. Transmission electron microscopy demonstrated that all gland units consist of a monolayer of epithelial cells surrounding a large central lumen. The gland units are enveloped by a thick basal lamina containing bundles of muscle cells. Microvilli are present at the apical plasma membrane domain of the gland cells, thus enlarging the available membrane area for saliva secretion towards the large gland lumen, although occasionally budding vesicles could be observed among the microvilli. Cytochemical analysis showed that the salivary gland cells of T. infestans present abundant endoplasmic reticulum profiles and several lipid droplets.     

Composition and variability of the saliva of coreids in relation to phytoxicoses and other aspects of the salivary physiology of phytophagous Heteroptera

In the saciform, principal salivary glands ofMictis profana (Fabr.) (Coreidae: Heteroptera, Pentatomorpha), the contents of all lobes other than the posterior form gels consistent with their contributing to the solidifying saliva (stylet sheath); the posterior lobe secretes most if not all of a sucrose-hydrolysing enzyme that occurs in the nongelling (watery) saliva. Evidence for the occurrence of such an enzyme in the saliva of other coreids is presented. That inM. profana has a pH optimum near neutral and a substrate specificity consistent with sucrase (sucrose α-D-glucohydrolase, EC 3.2.1.48) as distinct from plant invertase (β-D-fruccofuranosidase, EC 3.2.1.26). Apart from some maltose-hydrolysing activity in the salivary glands, also consistent with sucrase, no other carbohydrases and neither proteinase nor lipase were detected. Phosphatases were found in gland extracts but not in secreted saliva. The saliva contains catechol oxidase (EC 1.10.3.1) from the accessory gland and ducts. Topical application of pilocarpine caused individualM. profana to secrete up to 58 μl watery saliva which showed continuous and independent variation of sucrase activity (up to ca 0.012 Units/μl) and pH (6–8), although high sucrase content tended to coincide with high pH. Total protein varied up to 10 μg/μl, and free amino acids up to 1.8 μg/μl leucine eq. Of the many proteins and/or protein subunits separable by electrophoresis of gland contents and saliva, four had sucrase activity, the most mobile with MW ca 66 000. TLC indicatedinter alia phenyl alanine and tyrosine, but no DOPA nor other diphenolic substrates of the catechol oxidase in the watery saliva. The soluble components of the saliva, which also has marked surfactant properties, are discussed in relation to the feeding process of coreids and the characteristic lesions they produce in their food plants.     

Comparison of pectolytic enzymes covalently bound to synthetic ion exchangers using different methods of binding

Several methods have been compared for the immobilization of a crude commercial pectolytic enzyme product (Pectofoetidin G3X) on derivatives of technical ion exchangers. The conditions were optimized for maximum retention of the enzyme activity and the efficiency of the hydrolysis of pectin solution was measured for all the immobilized enzyme preparations. The merits and drawbacks of the methods used are discussed.     

人类微孢子虫检测方法研究进展

微孢子虫(microsporidia)是一类专性细胞内寄生的单细胞真核生物。是引起微孢子虫病的真菌类病原。在已知并被命名的1500多种微孢子虫中,共有9个属中的17个虫种可以感染人。人类微孢子虫可侵染包括肠道、肝、肺、脑等部位,引起慢性腹泻、肝炎、角膜炎、脑炎、血液系统性感染等,严重影响人类健康。研究开发快速高效的人类微孢子虫诊断方法成为当前病原微生物检测领域研究的热点。人类微孢子虫的发现历史实际上是伴随检测方法的不断进步而逐渐进行的。这些检测方法包括,透射电镜(transmission electron microscopy)、苏木精-伊红染色(hematoxylin-eosin stain,HE)、亚甲蓝染色(methylene blue)、吉姆萨染色(giemsa)、革兰氏染色(gram stain)、韦伯氏改良三色染色法(Weber’s chromotrope-based staining)、荧光增白剂染色法(calcofluor white staining)、抗原检测、抗体检测、实时荧光定量PCR (quantitative real-time PCR,q PCR)、环介导...     

喷气燃料中污染微生物检测方法概况

微生物污染不仅降解喷气燃料,还严重威胁储存和飞行安全.喷气燃料中污染微生物的检测是有效治理微生物污染的前提.基于此,本文将喷气燃料中污染微生物检测方法分为传统法、分析生物学法以及分子生物学方法,并对三种方法优缺点进行了详细介绍.最后对喷气燃料中污染微生物检测方法进行了展望.     

The activity of the carbon metabolism enzymes inchromatium minutissimum after long-term storage

The activity of the enzymes of the tricarboxylic acid cycle and glyoxylate shunt, as well as of some enzymes involved in carbohydrate metabolism, were determined in the purple sulfur bacteriumChromatium minutissimum either maintained by subculturing in liquid medium or stored in the lyophilized state for 36 years. In cultures stored in the lyophilized state, the activities of the key enzymes of the tricarboxylic acid cycle, glyoxylate shunt, and Embden-Meyerhof-Parnas pathway were higher, whereas the activities of glucoses-phosphate dehydrogenase, pyruvate kinase, and ribulose bisphosphate carboxylase were somewhat lower than in cultures maintained by regular transfers.     

食物致敏蛋白及其检测方法

食物过敏是威胁人类健康的一大问题,并随着环境的恶化和新食物资源的出现而趋于严重,因此受到科研工作者,政府职能部门以及消费者的关注。本文就食物来源的致敏蛋白加以分类并对其结构特点进行了概述,同时也介绍了现阶段致敏蛋白的主要检测手段。以期对食品安全有进一步的了解和认识,从而减少因食物过敏造成的危害。     

Molecular cloning of cDNAs encoding a range of digestive enzymes from a phytophagous beetle, Phaedon cochleariae

To gain better knowledge of the variety of digestive enzymes in phytophagous coleopteran pests, a sequencing screen of 76 random cDNAs from a gut library from Phaedon cochleariae larvae was performed. The screen yielded 21 cDNAs encoding amino-acid sequences homologous to known digestive enzymes, most of them were cell wall-hydrolysing enzymes. The deduced protein sequences of 7 cDNAs encoding putative α-amylase, cysteine proteinase, trypsin, chymotrypsin, cellulase, pectinase and xylanase display all the structural features that characterize these enzymes in other eukaryotic organisms. Except the α-amylase and chymotrypsin cDNAs, the other cDNAs probably derive from multigene families. The distribution of the corresponding enzymatic activities at various developmental stages of P. cochleariae was examined. α-amylase activity is present in guts of larvae and adults, proteinases are abundant in guts of larvae and adults, but scarce in eggs and larval carcasses, xylanases are present in the guts of larvae and adults, as well as in carcasses of larvae, whereas cellulase and pectinase activities are distributed in larval and adult guts, larval carcasses, and eggs. Only a minor fraction of the cellulases is secreted by microorganisms, suggesting that P. cochleariae synthesizes most of its own cell-wall hydrolysing enzymes. The physiological role of the enzymes is discussed, as well as the significance of these results for pest management strategies involving transgenic plants expressing enzyme inhibitors.     

Cellulolytic activity in a phytophagous lepidopteran insect Philosamia ricini: The origin of the enzymes

The presence of cellulases in a phytophagous insect hitherto considered as devoid of any cellulolytic enzymes, has been reported for the first time in the phytophagous lepidopteran, the eri silkworm Philosamia ricini. Cellulose digestion in Philosamia ricini appears to occur independently of its gut flora and via enzymes synthesized by the insect itself. The failure of three wide spectrum antibiotics to induce any change in the cellulolytic activity in this insect at any stage of its development evinces the non-participation of its gut flora in cellulose digestion. Culturing the antibiotic-fed larval gut fluids in appropriate media revealed the ability of tetracycline to effect complete inactivation of all bacteria and fungi by day 4 whereas penicillin and streptomycin could achieve it only partially. The cellulolytic activity, however, in all insect groups remained unaffected. The suggests that it is the endogenous enzymes of P. ricini that catalyze cellulose hydrolysis. This has been further confirmed by long term feeding of antibiotics to the insects.     

线粒体功能的检测方法

线粒体为细胞内的能量工厂,对细胞的增殖、分化、存活以及稳态的维持起着重要的调节作用。线粒体功能障碍与机体生长、发育异常、认知发生障碍以及多种器官病变密切相关。线粒体形态、结构和功能的检测对于了解线粒体的稳态以及功能状态有着重要意义,线粒体的功能状态与线粒体膜电位、线粒体膜通道、线粒体Ca2+浓度、ATP生成、呼吸链复合体活性、活性氧生成以及DNA突变密切相关。本文就线粒体形态、结构和功能的检测方法及其研究进展进行了综述。     

中国荔蝽科名录（半翅目：蝽总科）

报道中国荔蝽科目前已知种类,共36种,隶属2亚科12属。其中黄比蝽Pycanum ponderosum Stl,1854和圆肩达蝽Dalcantha inermipes Stl,1863为中国新记录种。提供了各种在中国的地理分布信息。     

New record of Compsidolon elaegnicola Yasunaga (Hemiptera: Miridae) from Korea

In this paper, two Korean Compsidolon species, C. salicellum (Herrich-Schaeffer) and C. elaegnicola Yasunaga, were treated. Of these, C. elaegnicola Yasunaga, 1999, which was previously known only from Japan, is reported from Korea for the first time and diagnosed. A dorsal habitus image and illustrations of the male genitalia are provided.     

阔颈叶蝉属一新种记述(半翅目:叶蝉科)

记述阔颈叶蝉属Drabescoides 1新种,即长臂阔颈叶蝉Drabescoides longiarmus sp.nov..新种近似于圆突阔颈叶蝉Drabescoides umbonata Shang, Zhang et Shen,2003,主要区别为:本种体形稍大,翅脉色泽较深,体背、颜面黄褐色,雄虫阳茎干背面两片状脊大且显著靠拢,尾节侧瓣三角形,具2个刺突,连索干细,臂极长,两臂夹角小,阳基侧突端部"马蹄状",表面着生微齿,雌虫第7腹板后缘弧形深凹入.提供了新种的鉴别特征图.模式标本保存在贵州大学昆虫研究所.