Ultrastructural investigations of three taxonomic characters in the trunk region of Echinoderes capitatus (Kinorhyncha, Cyclorhagida)

The classification of Kinorhyncha is mainly based upon cuticular differentiations including closing apparatus, trunk cuticle, and various appendages. This paper investigates whether ultrastructural characters support taxonomic results based upon light microscopical characters. The trunk region of Eckinoderes cupitatus bears several epidermal glands and setae and one middorsal spine on the 6th zonite. These characters are constant in number and distribution. The epidermal glands are unicellular, merocrine, glandular cells with an opening built up by several ramified canals terminating in pores within a slightly elevated ring-like bulge. Setae are composed of two cells, one merocrine glandular cell and one sensory cell with microvilli surrounding the outlet differentiation of the glandular cell. The setae have a pore on its tip, where the secretory product is released. The middorsal spine bears a multiciliar sensory cell. No pore is developed on the tip of the spine.     

The sternal pore areas of geophilomorph centipedes (Chilopoda: Geophilomorpha)

Most geophilomorph centipedes have segmental clusters of exocrine glands whose opening pores are arranged in more or less well-defined sternal pore areas. We describe here the cuticular structures forming and/or accompanying the gland openings on the sternites and the shape of the pore areas along the body axis in representatives of most geophilomorph families. The cuticular ring around the pore may exhibit either of two forms. In Himantariidae ( Himantarium ) and in Dignathodontidae ( Henia ) the ring looks like a continuous ribbon with a visible suture, whereas in the representatives of the remaining families no suture is seen. As to the distribution of the pores on ventral surface of the body, we record the presence of pores on the last leg-bearing segment of Clinopodes flavidus , whereas that segment was described as poreless in all geophilomorphs. We also provide a taxonomic survey of shape and distribution of pore areas in the individual families, where the pore areas may take very different shapes that we regard as transformational homologues. As for the segmental distribution of sternal pore areas, there is a considerable amount of complexity along the trunk of geophilomorph centipedes, in contrast to the apparently uniform trunk structure.     

Morphological, micromorphological and histochemical studies on the parotid salivary glands of the one-humped camel (Camelus dromedarius).

The morphology, blood and nerve supply of the parotid salivary glands of the one-humped camel were studied in detail. The intraglandular portion of the duct system was also examined. The histological and histochemical studies showed that the parotid salivary glands of the camel are of the tubuloacinar type and are serumocoid in nature. The secretory acini and tubules show themselves in 3 different forms according to the different phases of their secretory cycle. The duct system of the gland contains goblet cells between its lining epithelium. The intercalated ducts show ampullation followed by narrowing that help in mixing the secretion. Intraepithelial glands are found in the terminal part of the parotid duct.     

Male antennal gland of Amitus spiniferus (Brethes) (Hymenoptera : Platygastridae), likely involved in courtship behavior

The functional anatomy of integumentary adjacent glands of the 4th male antennomere, termed male sex-antennomere (MSA4), of Amitus spiniferus (Brethes) (Hymenoptera : Platygastridae), is described. Externally, the lateral side of the MSA4 presents an elliptical, glabrous, and elevated plate with about 20 scattered pores. Internally, there is a glandular area consisting of some 20 isolated, 2-celled secretory units beneath the elevated plate. Each gland has a secretory cell, forming a cuticular receiving canal, and a canal cell, forming the conducting canal, which connects the receiving canal to the external glandular opening. The abundant secretion appears on the cuticular surface in cylindrical forms and as droplets, and probably acts as a recognition and/or an aphrodisiac pheromone during mating. This hypothesis is discussed with regard to behavioral observations reported for only 3 other known cases of similar glands in parasitoids. Modified antennomeres with specialized structures are briefly reviewed, and their secretory function and taxonomic importance in parasitic Hymenoptera, suggested.     

Ultrastructural investigation of the vesicular glands in Scutigera coleoptrata (Chilopoda,Notostigmophora)

In the notostigmophoran centipedes, two pairs of vesicular glands have evolved. These paired glands are situated in the first and second trunk segment and open via cuticular ducts in the upper part of the particular pleura. The vesicular glands of Scutigera coleoptrata were investigated using light and, for the first time, electron microscopical methods. The glands consist of wide sac‐like cavities that often appear vesicular. The epithelia of both glands are identically structured and consist of numerous glandular units. Each of these units consists of four different cells: a single secretory cell, a small intermediary cell, and one proximal and one distal canal cell. The intermediary cell forms a conducting canal and connects the secretory cell with the canal cells. Proximally, the intermediary cell bears microvilli, whereas the distal part is covered with a distinct cuticle. The cuticle is a continuation of the cuticle of the canal cells. This investigation shows that the ultrastructure of glandular units of the vesicular glands is comparable to that of the glandular units of other epidermal glands in Chilopoda and Diplopoda, although the glands look completely different in the light microscope. Thus, it is likely that the vesicular glands and epidermal glands share the same ground pattern. With regard to specific differences in the cuticular lining of the intermediary cells, a common origin of epidermal glands in Myriapoda and Hexapoda is not supported. J. Morphol. 2009. © 2008 Wiley‐Liss, Inc.     

The post-embryonic changes in Melipona quadrifasciata anthidioides Lep. (Hym. Apoidea). II. Development of the salivary glands system

The paper deals with the development of the salivary gland system in Melipona quadrifasciata anthidioides, which begins in the prepupal stage. The silk glands degenerate by autolysis at the end of the larval stage. Degeneration is characterized by cytoplasmic vacuolization and pycnosis of the nuclei of the secretory cells. The glandular secretory portion of degenerated silk glands separates from the excretory ducts. The salivary glands develop from the duct of the larval silk glands. The thoracic salivary glands develop from the ducts of the secretory tubules and the head salivary glands from the terminal excretory duct. The mandibular glands appear in the prepupa as invaginations of mandibular segments, and their differentiation to attain the adult configuration occurs during pupation. The hypopharyngeal glands have their origin from evaginations of the ventral anterior portion of the pharynx. A long tubule first appears with walls formed by more than one cellular layer. Then some cells separate from the lumen of the duct, staying attached to it by a cuticular channel in part intracellular. The initial duct constitutes the axial duct, in which the channel of the secretory cells opens. During the development of salivary and mandibular glands, they recapitulate primitive stages of the phylogeny of the bees. During the development of salivary glands system, mitosis accounts for only part of the growth. Most of the growth occurs by increase in size of cells rather than by cell division. In brown-eyed and pigmented pupae six days before emergence, the salivary gland system is completely developed, although not yet functioning.     

优雅蝈螽雄性附腺的超微结构及其腺管提取物对精子束的作用

为阐明优雅蝈螽Gampsocleis gratiosa Brunner von Wattenwyl雄性附腺的结构与功能的关系, 本文利用透射电镜(transmission electron microscope, TEM)技术研究了优雅蝈螽雄性附腺的超微结构, 利用微分干涉相差显微镜(differential interference contrast microscope, DIC)技术并结合雄性附腺匀浆提取物与精子束在体外的短暂培养, 研究了优雅蝈螽雄性附腺对精子束的作用。结果表明： 优雅蝈螽雄性附腺3类腺管组织结构相似, 腺管管壁为单层上皮细胞, 缺少内表皮, 说明其来源于中胚层。上皮细胞富含粗面内质网、 线粒体、 高尔基体, 具有分泌细胞的特点。腺管管腔中分泌物有4种形态, 即电子透明的物质、 电子致密的颗粒物质、 细纤维状物质以及绒球状物质。上皮细胞的分泌方式主要有2种, 即顶质分泌和局部分泌。乳白短腺管的匀浆提取物参与了帽状精子束解聚的过程, 乳白长腺管和透明腺管的匀浆提取物有维持精子束活性的作用。本研究结果为进一步阐明螽斯雄性附腺的生理功能奠定了基础。     

Cuticle Micromorphology of Pinus krempfii Lecomte (Pinaceae) and Additional Species from Southeast Asia

Cuticle micromorphology of the unusual Vietnamese pine, Pinus krempfii Lecomte, and three additional endemic southeast Asian species of Pinus L. (Pinaceae) is characterized for the first time. Taxa studied include (1) P. krempfii, typically placed in its own subgenus Ducampopinus (Chevalier) Ferré ex Little & Critchfield; (2) the endemic Vietnamese species Pinus dalatensis Ferré and (3) the southeast Asian species Pinus kwantungensis Chun ex Tsiang, both of subgenus Strobus; and (4) the widespread Asian species Pinus kesiya Royle ex Gordon of subgenus Pinus. The current and previous studies demonstrate that the genus Pinus and its subgenera are delimited by unique combinations of cuticular characters, although some of these characters may occur individually in other conifers. Cuticular micromorphology supports taxonomic assignment of P. krempfii to subgenus Strobus rather than to its own subgenus, a result that is also indicated by other anatomical studies and recent molecular studies. Sectional affinities of P. krempfii are usually with Parrya, subsection Krempfianae. An alternative classification of P. krempfii with subsection Gerardianae can be supported by micromorphological characters including broad cuticular bridges between stomata, details of the intercellular flanges of the epidermal cells, and usually an amphistomatic stomatal distribution. Features of other Asian species studied are consistent with their taxonomic assignments. The study demonstrates the utility of cuticle micromorphology to taxonomic delimitation within the family Pinaceae.     

Contribution of microscopic techniques to anatomical and morphological knowledge on Styrax officinalis L

The aim of this study was to precise anatomical and morphological features of the species Styrax officinalis with the help of current microscopic techniques, those features being of interest as valuable taxonomic characters. Typical hairy structures were observed on all surfaces of the aerial organs and their location, density and size were specified. Moreover, we demonstrated the occurrence of secretory glands in the leaf blades. These structures were revealed for the first time for this species.     

Ultrastructural features of the salt gland of Tamarix aphylla L.

Summary The salt gland in Tamarix is a complex of eight cells composed of two inner, vacuolate, collecting cells and six outer, densely cytoplasmic, secretory cells. The secretory cells are completely enclosed by a cuticular layer except along part of the walls between the collecting cells and the inner secretory cell. This non-cuticularized wall region is termed the transfusion are (Ruhland, 1915) and numerous plasmodesmata connect the inner secretory cells with the collecting cells in this area. Plasmodesmata also connect the collecting cells with the adjacent mesophyll cells.There are numerous mitochondria in the secretory cells and in different glands they show wide variation in form. In some glands wall protuberances extend into the secretory cells forming a labyrinth-like structure; however, in other glands the protuberances are not extensively developed. Numerous small vacuoles are found in some glands and these generally are distributed around the periphery of the secretory cells in association with the wall protuberances. Further, an unusual structure or interfacial apparatus is located along the anticlinal walls of the inner secretory cells. The general structure of the gland including the cuticular encasement, connecting plasmodesmata, interfacial apparatus, and variations in mitochondria, vacuoles, and wall structures are discussed in relation to general glandular function.     

Anatomical and histochemical characterization of extrafloral nectaries of Prockia crucis (Salicaceae)

Besides being vital tools in taxonomic evaluation, the anatomy of plant secretory structures and the chemical composition of their secretions may contribute to a more thorough understanding of the roles and functions of these secretory structures. Here we used standard techniques for plant anatomy and histochemistry to examine secretory structures on leaves at different stages of development of Prockia crucis, to evaluate the origin and development of the structures, and to identify the disaccharides and monosaccharides in the exudates. Fructose, glucose, and sucrose constituted up to 49.6% of the entire secretion. The glands were confirmed to be extrafloral nectaries (EFNs); this is the first report of their presence in the genus Prockia. These EFNs are globular, sessile glands, with a central concavity occurring on the basal and marginal regions of the leaf. The epidermis surrounding the concavity is secretory, forming a single-layered palisade that strongly reacts with periodic acid-Schiff's reagent (PAS) and xylidine Ponceau, indicators of total polysaccharides and total proteins, respectively, in the exudate. On the basis of the similarity of these glands to the salicoid teeth in Populus and Salix, we suggest that these three taxa are phylogenetically close.     

Taxonomy of the genus Ephedra. Significance of stem and leaf epidermis and cuticle

Epidermal and cuticular characters of 30 taxa of Ephedra (including 24 species and six additional varieties) are described and their taxonomic value is discussed.     

Variation of cuticle micromorphology of Metasequoia glyptostroboides (Taxodiaceae)

Leaf cuticle micromorphology of Metasequoia glyptostroboides Hu & W. C. Cheng was studied with SEM using samples collected from its natural population in south-central China and cultivated trees in Nanjing City. The cuticle characters from both natural and cultivated trees living in different environments allowed us to re-evaluate taxonomic values of certain cuticular characters and to assess their relationships with environmental factors and the degree of tree maturity. External and internal cuticular features of both adaxial (upper) and abaxial (lower) leaf surfaces revealed the following: (1) Cuticle micromorphology of M. glyptostroboides is distinct among Taxodiaceae, but that variation does not exceed the range of this family. (2) Except for an isolated tree outside the Metasequoia valley, the cuticular features displayed by individual trees from the main Metasequoia groves demonstrate a high degree of uniformity, which is in congruence with previous observations on the low population variability at the gross morphology level. (3) Cuticular characters of grafted Metasequoia trees living in different environments are identical to those of their original trees, indicating that no cuticular character of this species could be regarded as an environmental indicator. (4) Recognition of some unique cuticular features in a Metasequoia tree in an isolated location may lead to a rare source for increasing the variation of this endangered species.     

Examination of the interior of sand fly (Diptera: Psychodidae) abdomen reveals novel cuticular structures involved in pheromone release: Discovering the manifold

The males of many species of New World Phlebotomines produce volatile terpenoid chemicals, shown in Lutzomyia longipalpis s.l. to be sex/aggregation pheromones. Pheromone is produced by secretory cells which surround a cuticular reservoir which collects the pheromone and passes it through a cuticular duct to the surface of the insect. The pheromone then passes through specialised cuticular structures on the abdominal surface prior to evaporation. The shape and distribution of the specialised structures are highly diverse and differ according to species. In this study we used SEM to examine the interior cuticular pheromone collection and transport structures of 3 members of the Lu. longipalpis s.l. species complex and Migonemyia migonei. We found a new structure which we have called the manifold which appears to be a substantial extension of the interior tergal cuticle connected in-line with the cuticular duct and reservoir. The manifold of the Campo Grande member of the complex is longer and wider than the Jacobina member whereas the manifold of the Sobral member was shorter than both other members of the complex. Overall, the secretory apparatus of the Sobral member was smaller than the other two. The manifold of M. migonei was very different to those found in Lu. longipalpis s.l. and was positioned in a pit-like structure within the tergal cuticle. The secretory reservoir was connected by a short duct to the manifold. Differences in the size and shape of the manifold may be related to the chemical structure of the pheromone and may have taxonomic value. Examination of the interior cuticle by SEM may help to locate the secretory apparatus of vector species where pheromonal activity has been inferred from behavioural studies but the external secretory structures or pheromones have not yet been found.     

Development of female accessory glands of Chrysomya putoria (Wiedemann) (Diptera: Calliphoridae) during oogenesis

Females of Chrysomya putoria (Diptera: Calliphoridae) have two sexual accessory glands, which are tubular and more dilated at the distal extremity. The glands open independently into the common oviduct. Two morpho-physiological regions were distinguished in the longitudinal semi-thin sections of the glands. The secretory region is constituted by three layers: a cuticular intima, lining the lumen, followed by a layer of small cells, and then a layer of very large secretory cells. The ductal region of the gland presents only two layers: the cuticular intima and a cellular layer. In both regions a basement membrane is present. Each secretory cell has in its apical region a reservoir, which enlarges throughout oogenesis; in its basal region there is a large nucleus. The ductal cells are cylindrical and smaller than the secretory cells. The glandular secretion is synthesized in the cytoplasm of the secretory cells, stored and/or modified in the reservoir, then drained to the lumen through an end apparatus seen in the apical region of the secretory cell. Histochemical tests indicate that this secretion is a glycoprotein. Measurements of the glands from females at different physiological conditions and fed on different diets correlate with the results obtained for changes in the ovary during oogenesis. Cell number averaged 561.2 ± 77.54 per gland. There was no increase in cell number during oogenesis.     

Morphology and ultrastructure of paired prototergal glands in the adult rove beetle Philonthus varians (Coleoptera, Staphylinidae)

Philonthus and other genera of Philonthina possess a pair of prototergal glands located in the first abdominal tergum and hidden at rest by hind wings and elytra. In Philonthus varians they occupy the whole length of the tergum and form a pouch-like invaginated reservoir with a scaly glandular zone and a smooth outlet. A grille of long setae covers the opening of each gland. The fine structure of these glands is given for the first time. Three types of cells are found in the glandular epithelium. Epidermal cells underlie the cuticular scales, numerous class 1 secretory cells open in the centre of calyces made of finger-like processes of the cuticle, and class 3 cells are connected to pored tubercles. A cytological comparison is made with the diverse class 1 cells described to date in Coleoptera. In these cells different evolutionary trends are shown in the structure of the cuticular apparatus, particularly in the number, size and position of the cuticular apertures as well as in the length and abundance of epicuticular filaments. A possible defensive function of the prototergal glands against pathogens and their interest for the phylogenetic study of Staphylininae are discussed.     

Carbonic anhydrase in the rat salivary glands: distribution and ultrastructural localization

Rat salivary glands were studied by Hanson's method to specify the ultrastructural localization of carbonic anhydrase (CA). Two different procedures were used: 1) The embedding of the tissues in water-soluble resins, followed by the incubation of the resin sections on the medium. 2) The embedding in epon-araldite of previously incubated frozen sections. Light and electron microscopy were used to observe the distribution and the ultrastructural localization of the cobalt precipitate. In parotid and mandibular glands, CA was localized in the secretion granules and the hyaloplasma of the secretory endpieces. The enzyme was also detected on the basal and lateral membranes of the striated duct cells in the three glands. In the convoluted granular duct cells of the mandibular gland CA was found in the hyaloplasma only. In the sublingual gland, CA was localized in the hyaloplasma of the serous crescents and no activity was detected in the mucous tubules. As regards the localization of the enzyme in the granules of the secretory endpieces of parotid and mandibular glands, it appears that CA has to be considered as a secretory product of these cells; this localization is consistent with the presence of the enzyme in rat saliva.     

The histology and ultrastructure of the salivary glands of Neopanorpa longiprocessa (Mecoptera: Panorpidae)

The salivary glands of Panorpidae usually exhibit distinct sexual dimorphism and are closely related to the nuptial feeding behavior. In this study, the salivary glands of Neopanorpa longiprocessa were investigated using light microscopy and transmission electron microscopy. The salivary glands are tubular labial glands and consist of a scoop-shaped salivary pump, a common salivary duct, and a pair of salivary tubes. The male and female salivary glands are remarkably different in the bifurcation position of the common salivary duct and the length and shape of the secretory tubes. Compared with the simple female salivary glands, the male’s are more developed as their paired elongated salivary tubes can be divided into two parts, the glabrate anterior tube and the posterior tube with many secretory tubules. The ultrastructural study shows that the male salivary tubes have strong secretory function. The existence of different secretion granules indicates that there are some chemical reactions or mixing occurring in the lumen. Based on the ultrastructural characteristics, the functions of the different regions of the salivary tube have been speculated. The relationship between the salivary glands and nuptial feeding behavior of N. longiprocessa has been briefly discussed based on the structure of the salivary glands.

     

Morphology of sternum V glands in three caddisfly species, Stenopsyche marmorata, Eubasilissa regina and Nemotaulius admorsus (Insecta: Trichoptera)

The present study describes the morphology of the sternum V gland of three caddisfly species, Stenopsyche marmorata Navas, Eubasilissa regina (McLachlan) and Nemotaulius admorsus (McLachlan), each of which belongs to a different family of the order Trichoptera, using light and scanning electron microscopy. In both sexes of these three species, the gland orifices are located on the sides of the sternum V as crescent-shaped slits, and are connected with the glandular tissue via cuticular gland ducts. The shapes of glands differ greatly among species; a slender ampullar form in S. marmorata , a flattened saccular form (horseshoe shape) in E. regina and a kidney shape in N. admorsus . The glands are composed of four essential components: large secretory cells, small reservoir cells, the lining of the reservoir and the gland duct. In S. marmorata and E. regina , additional components, muscle fibers, are present around the small reservoir cells. The secretory cells covering the whole outer surface of the gland are very large, and form many bunches in S. marmorata and E. regina , but do not form them in N. admorsus . The small reservoir cells lie inside the layer of the secretory cells and are tightly connected with the cuticular lining of the reservoir. The linings become thick cuticular ducts near the gland orifices. Histological features suggest that the secretory cells of the sternum V gland of Trichoptera belong to the type of class 3 cells in insect epidermal glands.     

Foregut glands of Solenogastres (mollusca): anatomy and revised terminology

In the molluscan class Solenogastres, different types of foregut glands vary in number, structure, and location within the foregut. The present article describes their anatomy and cytology and intends to clarify their confused terminology. Pharyngeal glands, esophageal glands, and the more complex dorsal and ventrolateral foregut glands can be distinguished. The ventrolateral foregut glands (ventral foregut glandular organs, ventral salivary glands of auct.), in the literature subdivided previously into four types, are revisited here in the context of current vertebrate gland terminology. The results of recent investigations are added to earlier ones, and a classification system for these multicellular glands is proposed. This system is based on cytological characters of glandular cells (intra- or extraepithelial), characters of the associated musculature (inner or outer musculature), location of the gland relative to the pharynx epithelium (endoepithelial or exoepithelial), characters of the gland openings (paired or unpaired), morphology of the gland duct (simple or branched), and some additional features like the arrangement of glandular cells along the gland ducts. Gross morphology and anatomy of ventrolateral foregut glands constitute useful taxonomic characters in determining higher taxa (family level), and finer details of the anatomy and cytology are useful in determining lower levels (genus and species). Possible pathways for the evolution of the different gland types of Solenogastres in relation to foregut glands present in the other molluscan clades are presented. The importance of ventrolateral foregut gland characters for phylogenetic considerations within the Solenogastres is discussed.