Fine structure and formation of the eggshell in scorpionfly Panorpa liui Hua (Mecoptera: Panorpidae)

The morphology and formation of the eggshell in the scorpionfly Panorpa liui Hua were examined with light microscopy and scanning and transmission electron microscopy. During oogenesis of the scorpionfly, the follicle cells multiply by mitotic divisions and diversify into four morphologically distinct subpopulations, three of which are engaged in the eggshell formation and mold various parts of chorion. The eggshell consists of three layers: An inner vitelline membrane, an outer chorion, and a precursor extrachorion. The chorion constitutes a very compact endochorion, a rough fibrillar exochorion, and a polygonal meshwork of elevated ridges. At proximal end of ovarioles the chorion of matured oocyte is covered with a loose membrane, which might be the remnant of follicle cells. The jelly substance, which acts as lubricant to protect the oviducts and ovulated eggs during ovulation, might add to the top of polygonal ridges as the outermost extrachorion after oviposition. The eggshell formation process in Panorpa is tentatively proposed. Microsc. Res. Tech. 2009. © 2009 Wiley-Liss, Inc.     

Egg envelopes of Armadillidium vulgare (Latreille, 1804) (Crustacea,Isopoda Oniscidea): Ultrastructure and lectins binding

The ultrastructural study carried out on (a) oocytes of Armadillidium vulgare during vitellogenesis, (b) mature eggs taken from the ovaries during the parturial moult of the posterior half of the body, and (c) fertilized eggs collected within a few hours of their release into the brood pouch, has clearly demonstrated that before the fertilization the chorion is the only envelope present in the egg of oniscidean isopods. In the mature eggs, the chorion appears as a uniformly electron‐dense lamina, about 0.4–0.5 µm thick, which does not show any specialized area. A second envelope, described by other authors as vitelline envelope, is formed above the oolemma only right after fertilization and appears separated from the chorion by a space full of liquid. The ways in which the genesis of this envelope is realized are not yet clear; it could be interpreted rather as a fertilization membrane. The investigations carried out with the aid of a battery of FITC‐lectins have highlighted the presence at the chorion surface of unfertilized eggs of various saccharide residues distributed in uniform way. No significant change was observed in the pattern of lectins binding to the chorion of eggs taken from the brood pouch, thus demonstrating how, after the fertilization, no significant rearrangement in the distribution of saccharide residues present on the egg surface occurs in A. vulgare. The ways in which, therefore, the recognition, the binding and the entry of the peculiar sperm of oniscidean isopods into the egg occur, still remain all to be deciphered. Microsc. Res. Tech. 79:792–798, 2016. © 2016 Wiley Periodicals, Inc.     

Progressive chorion morphology during egg development in Samia ricini (Donovan)

The egg of Samia ricini (Donovan), is oval or laterally flattened ellipsoid, freshly laid eggs are candid white while the chorion is colorless and semi‐transparent. The surface of the chorion is covered with network patterns of polygons and their shapes are common in the whole surface region. The boundaries between polygons made ridges had distinct acropyles at three‐cell junctions. The numbers of aeropyles are variable according to their structures both in the lateral flat and marginal regions. During the course of egg development, no significant structural changes were observed in either the polygonal structures or the overall morphology of the egg. However, the size of the aeropyles kept on changing as the egg matures. The aeropyle increases initially upto day‐9 of egg development and then decreases as it approach hatching. Lines of weaknesses were not observed at time of hatching or close to it. Hatching process of the newly emerge larvae are through gnawing. The larva eats their way out through the chorion membrane mostly from the anterior region. Egg buster or spine which aid in hatching are not present in the newly emerge larvae. This article was published online on 25 September 2009. An error was subsequently identified. This notice is included in the online and print versions to indicate that both have been corrected 6 January 2010. Microsc. Res. Tech., 2010. © 2009 Wiley‐Liss, Inc.     

Ultrastructure of oocytes of the Urostreptus atrobrunneus (Diplopoda,Spirostreptida, Spirostreptidae): A potential urban centers plague

The knowledge of the process of egg formation is indispensable for understanding the mechanisms involved in the reproduction of different species. In this context, the objective of this work was to describe the ultrastructure of the oocytes of Urostreptus atrobrunneus (Spirostreptida), a potential plague of urban centers in different locations of São Paulo State. The lack of knowledge about the morphology, physiology, and the reproductive behavior of the species have hindered an effective control of it. The oocytes of U. atrobrunneus presented three development stages: young oocyte or type I; intermediary oocyte or type II; and mature oocyte or type III. During the oocyte development, the cytoplasm become filled with several globules of protein, drops of lipids, and sphaerocrystals, and it was not observed in many organelles in the oocytes with exception of mitochondria, abundant, principally in young oocytes. The vitelline membrane is also deposited in a discontinuous form and the chorion does not present differentiation of layers. The follicular epithelium alters its shape according to the development phase of the oocyte. Part of the vitellus is from exogenous origin and part is endogenous. Before this, only two studies about the ultrastructural analysis of the female germ cells of diplopods were published. Microsc. Res. Tech. © 2012 Wiley Periodicals, Inc.     

Oogenesis of Diadegma semiclausum (Hymenoptera: Ichneumonidae) and its associated polydnavirus

We present a detailed ultrastructural analysis of ovary and calyx cell differentiation of Diadegma semiclausum. Numerous gametangia in various developmental stages were examined with electron microscopy to characterize the ultrastructure features of oogenesis, the most important of which is the development of nurse cells. In the germarium, the undifferentiated germ cells diversify, and one of the central cells of the cluster differentiates into an oocyte while the remaining become nurse cells. Germ cells continue developing in the vitellarium until mature and then enter into the calyx region. The calyx epithelium contains typical ichneumonid polydnaviruses with the following characteristics: (1) the virus particles assemble in the nuclei of calyx cells where they acquire an initial (inner) membrane, then migrate through the cytoplasm and budd out into the lumen of the ovary, at which time they acquire a second envelope (outer membrane); (2) the particle has a genome comprising several DNA segments. However, this new polydnavirus (Diadegma semiclausum polydnavirus) in the genus ichnovirus was not attached to the surface of the egg chorion.     

The structure and ultrastructure of the egg capsule of Brachyptera risi (Plecoptera,Nemouroidea, Taeniopterygidae) with some remarks concerning choriogenesis

The organization of the egg capsule of the euholognathan stonefly, which represents the family Taeniopterygidae (Nemuroidea) was investigated using light and electron microscopy techniques. The presence of a complex, multilayered egg capsule, composed of a vitelline envelope, multilayered chorion, and extrachorion is described. The morphology of the eggshell of Brachyptera risi was compared with that of euholognthan and systellognathan egg coverings and the ground plan of the egg capsule in Plecoptera was discussed. Microsc. Res. Tech. 78:180–186, 2015. © 2014 Wiley Periodicals, Inc.     

Structural and ultrastructural features of the Malpighian tubules of Dolycoris baccarum (Linnaeus 1758), (Heteroptera: Pentatomidae)

The morphology and ultrastructure of the Malpighian tubules of Dolycoris baccarum were analyzed by scanning (SEM) and transmission (TEM) electron microscopy in order to determine their functional organization. The Malpighian tubules are compared with similar structures of other insects based on cell structure and functional organization. The Malpighian tubules of D. baccarum extend from the midgut–hindgut region of the digestive tract. The Malpighian tubules are divided into two regions: the proximal segment is short and flattened and the distal segment is long, stringy in shape and free in hemolymph. The tubules are generally long and narrow. There is a large number of trachea around the tubules. They consist of a single layer of epithelial cells. It is observed in the TEM observation that the epithelial cells have numerous microvilli at the apical side of the cells. At the basal side of the cells, there is a great number of membrane foldings and mitochondria among them. Besides some spherites, mitochondria, lysosome‐like bodies, and large or small granules can be distinguished in the cells. With this study, we aimed to demonstrate the ultrastructure of the Malpighian tubules of D. baccarum and differences or similarities with other species.     

CsI(Tl)-calorimeter calibration with positive-kaon decay products

The CsI(Tl) calorimeter was calibrated in the KEK-E246 experiment withK _μ2-andK _π2-positivekaon decays. The following calorimeter parameters were obtained: an energy resolution (σ) of 4.1% forE=242.5 MeV, a π⁰ invariant-mass resolution (σ) of 5.6%, and an angular resolution (σ) of 3.1^o.     

Morphology and distribution of antennal sensilla of female Phyllotreta striolata (Fabricius) (Coleoptera: Chrysomelidae)

Phyllotreta striolata (Fabricius) is an important pest of Brassicaceae in Southeast Asia and North America. Using scanning electron microscopy, we observed the external structure, number, and distribution of the antennal sensilla in P. striolata females to discuss the putative function of these sensilla in host location and oviposition behaviors. The antenna of female P. striolata is filiform, composed of a scape, a pedicel, and a flagellum with 9 flagellomeres. Five types of sensilla were identified, including sensilla cheaetica, sensilla trichodea, Böhm bristles, sensilla auricillica, and sensilla basiconica (five subtypes, SB1–SB2). External structure and distribution of antennal sensilla are compared with data from other insect species. In addition, we discuss the possible functions of antennal sensilla based on their characteristics. Microsc. Res. Tech. 79:219–226, 2016. © 2016 Wiley Periodicals, Inc.     

Red-shifted fluorescent proteins monitor enzymatic activity in live HT-1080 cells with fluorescence lifetime imaging microscopy (FLIM)

Membrane type 1 matrix metalloproteinase (MT1‐MMP) is a membrane‐tethered collagenase primarily involved in the mechanical destruction of extracellular matrix proteins. MT1‐MMP has also been shown to be upregulated in several types of cancers. Many coordinated functions of MT1‐MMP during migration and invasion remain to be determined. In this paper, live cells from the invasive cell line HT‐1080 were imaged using an intracellular Förster resonance energy transfer‐based biosensor specific for MT1‐MMP; a substrate specific for MT1‐MMP was hybridized with the mOrange2 and mCherry fluorescent proteins to form the Förster resonance energy transfer‐based sensor. The configuration of the biosensor was determined with fluorescence lifetime‐resolved imaging microscopy using both a polar plot‐based analysis and a rapid data acquisition modality of fluorescence lifetime‐resolved imaging microscopy known as phase suppression. Both configurations of the biosensor (with or without cleavage by MT1‐MMP) were clearly resolvable in the same cell. Changes in the configuration of the MT1‐MMP biosensor were observed primarily along the edge of the cell following the removal of the MMP inhibitor GM6001. The intensities highlighted by phase suppression correlated well with the fractional intensities derived from the polar plot.     

Detection of CD133 (prominin‐1) in a human hepatoblastoma cell line (HuH‐6 clone 5)

We examined CD133 distribution in a human hepatoblastoma cell line (HuH‐6 clone 5). We directly observed the cultured cells on a pressure‐resistant thin film (silicon nitride thin film) in a buffer solution by using the newly developed atmospheric scanning electron microscope (ASEM), which features an open sample dish with a silicon nitride thin film window at its base, through which the scanning electron microscope beam scans samples in solution, from below. The ASEM enabled observation of the ventral cell surface, which could not be observed using standard SEM. However, observation of the dorsal cell surface was difficult with the ASEM. Therefore, we developed a new method to observe the dorsal side of cells by using Aclar® plastic film. In this method, cells are cultured on Aclar plastic film and the dorsal side of cells is in contact with the thin silicon nitride film of the ASEM dish. A preliminary study using the ASEM showed that CD133 was mainly localized in membrane ruffles in the peripheral regions of the cell. Standard transmission electron microscopy and scanning electron microscopy revealed that CD133 was preferentially concentrated in a complex structure comprising filopodia and the leading edge of lamellipodia. We also observed co‐localization of CD133 with F‐actin. An antibody against CD133 decreased cell migration. Methyl‐β‐cyclodextrin treatment decreased cell adhesion as well as lamellipodium and filopodium formation. A decrease in the cholesterol level may perturb CD133 membrane localization. The results suggest that CD133 membrane localization plays a role in tumor cell adhesion and migration. Microsc. Res. Tech. 76:844–852, 2013. © 2013 Wiley Periodicals, Inc.     

Antennal sensilla of Eucryptorrhynchus chinensis (Olivier) and Eucryptorrhynchus brandti (Harold) (Coleoptera: Curculionidae)

Eucryptorrhynchus chinensis (Olivier) (Coleoptera: Curculionidae) and E. brandti (Harold) (Coleoptera: Curculionidae) are the two most important pests of tree‐of‐heaven, Ailanthus altissima (Mill.) Swingle and its variety Ailanthus altissima var. Qiantouchun in China. They are also considered potential biological control agents for tree‐of‐heaven in North America. In this study, the external morphologies and antennal sensilla of both species were examined using scanning electron microscopy to better understand their host‐finding mechanisms. Eleven morphological sensilla types were recorded, that is, Böhm bristles, six types of sensilla chaetica (Sch. 1–6), two types of sensilla basiconica (Sb. 1–2), and two types of sensilla trichodea (St. 1–2). Sch. 5 were absent from the antennae of E. chinensis, while Sch. 2 were absent from the antennae of E. brandti. Abundant cuticular pores were present on the antennae of both species. Three types of sensilla on the antennae of E. chinensis that were not found in a previous study, and ten different types of sensilla on the antennae of E. brandti were identified for the first time. The possible functions of the sensilla types are discussed based on a comparison with previous studies. Four types of sensilla (Sb. 1, Sb. 2, St. 2, and Sch. 6) on the antennae of both species indicate chemoreception may play a significant role in host location. Microsc. Res. Tech. 76:968–978, 2013. © 2013 Wiley Periodicals, Inc.     

Immunocytological detection of salivary mucins (MUC5B) on the mucosal pellicle lining human epithelial buccal cells

The mucosal pellicle is defined as the protein film adsorbed onto oral mucosa. This study aimed at characterizing the ultrastructure of human epithelial buccal cells and localizing salivary mucins MUC5B, a major constituent of the mucosal pellicle. Cells were sampled from the buccal surface and prepared for Transmission Electron Microscopy using high‐pressure freezing/cryosubstitution followed by immunogold labelling of MUC5B. Morphologically, cells were visualized as typical cells of the superficial layer of a squamous nonkeratinized epithelium with a partly degraded plasma membrane. The outer surface of the plasma membrane was lined with a biological material of medium electron density. MUC5B were detected in the extracellular space, and particularly in the vicinity of the plasma membrane, sometimes onto fibrils protruding from the membrane. This area was, therefore, considered as constituting the mucosal pellicle, which appeared as a mixed film of both salivary and epithelial components. The distribution of gold particles suggested that the surface of the pellicle was not uniform, and that the film thickness could reach up to 100 nm. This work showed the feasibility of visualizing and characterizing the mucosal pellicle directly on human epithelial buccal cells sampled in a noninvasive manner. Microsc. Res. Tech. 77:453–457, 2014. © 2014 Wiley Periodicals, Inc.     

A SEM study of the antenna and mouthparts of Omosita colon (Linnaeus) (Coleoptera: Nitidulidae)

There are direct relationships between the behavioral mechanisms and sensilla. To obtain a better understanding of the behavioral mechanisms in Omosita colon (Linnaeus) (Coleoptera: Nitidulidae), we investigated the types, quantities, and distribution of sensilla on the antenna and mouthparts of O. colon by scanning electron microscopy. The clavate antenna comprised the scape, pedicel, and nine segment flagellomeres and had six types of sensilla, including two subtypes of sensilla chaetica (SC), three subtypes of sensilla basiconica (SB) and sensilla trichodea (ST), and one type of sensilla cavity, sensilla styloconica, and Böhm bristles (BB). The chewing mouthparts of O. colon consist of the labrum, mandible, maxillae, labium, and hypopharynx and had seven types sensilla, including two subtypes of SC and sensilla placodea, seven subtypes of SB, and one type of BB, ST, sensilla coeloconica, and sensilla campaniformia. In this research, we also deduced the relationships between the sensilla on the antenna and mouthparts and their functions.     

Development and morphological changes in the vaginal closure membrane throughout gestation in Galea spixii (Rodentia: Caviidae)

Present research was carried out in order to perform the monitoring of development, recognizes the type of tissue and describes histological and cellular changes of the vaginal closure membrane (VCM) throughout pregnancy in Galea spixii. The results showed that at 20 days of gestation (DG), the VCM occludes completely the external vaginal ostium. Microscopically, the VCM presented juxtaposed cells, derived from the stratum germinative of the stratified epithelium of vaginal mucosa at 20 DG and areas with cell clusters with the presence of intercellular spaces in the final stages of pregnancy (40‐50 DG). At 0 DG, the stratified epithelium of vaginal mucosa presented all strata but at 20 DG presented stratified epithelium without the stratum corneum and stratum granular and showed communicant junctions by desmosomes and interdigitations in the cell membrane compound the VCM. Gradually from 40 to 50 DG the stratum germinative became barely perceptible. Many cells showed apoptotic nuclei and emerged many intercellular spacing. So, the interdigitations and desmosomes were not observed. Here, it was demonstrated for the first time that the VCM is formed after the extinction of the stratum granular and corneum of the vaginal mucosa epithelium, with the proliferation of the cells of stratum germinative and communication and junction through desmosomes and interdigitations of these cells. At the end of pregnancy, cellular apoptosis; the spread of stratum germinative; and, absence of cellular communication and junction may be responsible for the weakening of the VCM and may assist the process of rupture of this membrane. Microsc. Res. Tech. 79:359–364, 2016. © 2016 Wiley Periodicals, Inc.     

Morphology,distribution, and abundance of antennal sensilla of male and female macropterous and brachypterous small brown planthopper,Laodelphax striatellus (Fallén) (Hemiptera: Delphacidae)

The antennal sensilla of both genders of macropterous and brachypterous adults of the small brown planthopper, Laodelphax striatellus (Fallén) (Hemiptera: Delphacidae) were examined using light and scanning electron microscopy. Scanning electron microscopy revealed seven types of antennal sensilla in adult L. striatellus which were not evenly distributed on all antennal segments. Sensilla chaetica, a sensillum campaniformium and a Böhm bristle were found on the scape. Sensilla chaetica, sensilla trichodea, sensilla placodea which always present as plaque organs, sensilla basiconica and a sensillum campaniformium were present on the pedicel. Three sensilla basiconica and one sensillum coeloconicum containing two sensory pegs were located on the swollen sensory region of the basal flagellum. Pores observed on the surface of s. trichodea and s. placodea suggest these organs probably play a role in olfaction, whereas the aporous s. chaetica with flexible sockets probably function as mechanoreceptors. The aporous s. basiconica with inflexible sockets are probable to be thermo‐hygroreceptors while the Böhm bristle and s. campaniformia may act as antennal proprioceptors. The function of s. coeloconicum remains uncertain. The numerical dominance of antennal olfactory receptors suggests olfaction is an important function of the antenna in L. striatellus. Although a small degree of sexual/wing dimorphism was observed in the numbers of sensilla and in the length and width of antennae and antennal segments, the basic shape and structure of the antennae and antennal sensilla did not differ between the gender or wing form in L. striatellus. Microsc. Res. Tech. 2012. © 2012 Wiley Periodicals, Inc.     

Structure and distribution of antennal sensilla in Pseudosymmachia flavescens (Brenske) (Coleoptera: Scarabaeidae: Melolonthinae)

Morphology, microstructure, and distribution of antennal sensilla were compared between female and male Pseudosymmachia flavescens (Brenske) (Coleoptera: Scarabaeidae: Melolonthinae). Lamellate antennae of P. flavescens were shown to have typical scape, pedicel, and flagellum segments. The flagellum consists of a four-segmented funicle and a three-segmented club. The lengths of their pedicel and funicle were found to be similar in females and males. Distinct sexual differences were observed in the length of lamellar segments. Nine types/subtypes of sensilla were identified on the antennae of both sexes, including Böhm sensilla, sensilla trichodea, sensilla basiconica (SB), and two subtypes for sensilla chaetica, sensilla coeloconica, and sensilla placodea each. Olfactory sensilla (e.g., SB and placodea) are mainly located on three lamellar segments of the antennal club. Variation was also seen in abundance of various types of antennal sensilla, with males possessing significantly more sensilla than females. Sensilla placodea were the most abundant, and their number in males was twice of that in females, showing a clear sexual dimorphism. The difference in the distribution of sensilla placodea might reflect their roles in sexual chemical communication.     

Scanning electron microscopy analysis of the cephalic sensilla of Chrysolina aeruginosa Fald. (Coleoptera,Chrysomelidae)

Chrysolina aeruginosa Fald. (Coleoptera, Chrysomelidae) is an important pest of Artemisia ordosica Krasch. In recent years, this phytophagous beetle has spread rapidly throughout northwest China, which has led to mass mortalities of the A. ordosica. This pest has caused great damage to the local ecology. To address this problem, this study compared the sensilla types and their densities on the antennae, maxillary palps, and labial palps of C. aeruginosa. Six different types of sensilla were observed on the antennae using scanning electron microscopy, i.e., sensilla chaetica, sensilla trichodea, sensilla basiconica, sensilla coeloconica, sensilla styloconica, and Böhm bristles. Sensilla chaetica were the main sensilla on the antennae. There was a significant difference in the distribution and density of sensilla trichodea between males and females. Sensilla basiconica were distributed from the fifth to the ninth flagellomeres. Sensilla coeloconica and sensilla styloconica were usually found from the fifth to the eighth flagellomeres. Böhm bristles were found only on the terminal region of the scape and pedicel. Sensilla chaetica and sensilla twig basiconica were observed on the maxillary and labial palps. Sensilla chaetica were distributed all over the maxillary and labial palps. Sensilla twig basiconica were located in the distal areas of these two types of palps. In this study, we also discussed the responses of C. aeruginosa to the volatile semiochemicals produced by their host plants and the behaviours exhibited during host and habitat selection. Microsc. Res. Tech. 76:423–431, 2013. © 2013 Wiley Periodicals, Inc.     

Antennal and mouthpart sensilla of Acanthoscelides obtectus say (Coleoptera: Bruchidae)

Acanthoscelides obtectus, a serious pest with a worldwide distribution, damages stored seeds of Phaseolus sp. To acquire a better understanding of the sensory orientation of bean weevils, their antennal and palpal sensilla were investigated. The antennae and palps possess several types of sensory hairs: blunt‐tipped sensilla chaetica and trichoidea and also sharp‐tipped sensilla trichoidea, these last being the most numerous. Sensilla basiconica are present only on the flagellomeres, but Böhm bristles occur on the basal sclerite and scape of the antennae. The terminal segments of the maxillary and labial palps bear a group of sensilla styloconica with single apical pores. Sensilla coeloconica are located only on the terminal palpal segments. They were unable to detect any distinct morphological differences between males and females. The possible chemosensory, mechanosensory, and thermo‐/hygroreceptive functions of the sensilla are discussed.