Epithelial Sac Research Articles

Antenna development, function and its direct or indirect impact on physiology and behaviour of Drosophila melanogaster

AbstractSensory mechanotransduction is the process of deciphering physical stimuli into neural electrical receptor potentials, essential to Drosophila, the fruit fly. Nearly every aspect of an adult Drosophila intricate behavioural repertoire that involves the senses of proprioception, hearing, touch, olfaction, balancing and graviception. Mechanotransduction are mediated by a wide variety of specialized sensilla and sensory neurons that comprise the antenna. The eye and antenna of Drosophila melanogaster are derived from a cluster of approximately 23 cells that are set aside during embryonic development and are constantly divided during the three larval stages, organizing into an epithelial sac known as the eye‐antennal imaginal disc. During late larval and pupal development, the forward lobe of this epithelium, known as the antennal disc, gives rise to the antenna (an organized tripartite structure), whereas the posterior lobe, known as the eye disc, gives rise to the eye. The development of the antenna is a complex and intricate process that relies on the interplay of numerous genes. Each gene involved contributes to the regulatory network that governs the formation, differentiation, and patterning of specific structures within the antenna, ensuring its proper functionality. Thus, aberrant expression or mutation of any gene results in a faulty antenna. The defectiveness appears in terms of antennal structure leading to loss of function including defective behaviour found in an organism. A similar kind of structure–function relation of hearing with a behavioural defect has been reported in vertebrates. Some of the behavioural defects associated with genes are conserved in both vertebrates and Drosophila. Thus, a behavioural assay is an adaptable approach to studying the functionality of various genes associated with the antennae. Here a crucial relationship is established between the genetic regulation of mechanosensory neurons and an organism's behaviour. The current review summarizes antennae development, function and several methods used to study the mechanosensory behaviour associated with Drosophila antennae.

In preprints: get to know your neighbours – cell interface surveillance through a molecular zip code

In preprints: get to know your neighbours – cell interface surveillance through a molecular zip code

Imaginal Disc Regeneration: Something Old, Something New.

Imaginal discs are simple epithelial sacs found in Drosophila larvae, which generate adult structures including wings and legs. The first studies of imaginal disc regeneration involved technically challenging transplantation experiments. Yet despite the difficulty, many aspects of regeneration including wound healing, blastema formation, and the repatterning of regenerated tissue were characterized. An important discovery was the phenomenon of transdetermination, where a small group of cells in regenerating tissue collectively switch fate ("collective cell reprogramming"). The development of genetic tissue-ablation systems over the last 12 years has energized this field, by making experiments less technically challenging, more reproducible, and by incorporating additional genetic analysis. Recent progress includes defining mechanistic links between early responses to wounding and the signaling pathways that drive proliferation, uncovering a role for localized silencing of damage-responsive enhancers to limit regenerative capacity as tissues mature, and identifying genes that maintain cellular plasticity within acceptable limits during regeneration.

Dental Roots: Formation, Lengthening and Malformations of Roots

The Hertwig’s Epithelial Root Sheath (HERS) includes two layers: the Outer Enamel Epithelial Root Sheath and the Inner Enamel Epithelium Epithelium (IEE and OEE). They contribute both to the root formation. The inner columnar epithelial cells (IEE) of the dental papilla are formed by cells located near the dental papilla. They are at the origin of odontoblasts expressing FGF-4, -8 and -9 and at later stages BMP-2 and BMP7. The Outer Epithelial cells (OEE) express SHH, Msx2, enamel matrix proteins, paxillin, and Pax-6. When the cells of the HERS dissociate, intercellular spaces enlarge. Cells migrate from the epithelial sac, and underwent phenotypic inter conversion into cementoblasts and later cementocytes. The Hertwigs enamel epithelium contributes to cementum formation. Epithelial rest of Malassez is remnants of the Hertwig’s root sheath. They are implicated in cementogenesis. Root lengthening and dentin thickening are involved in root elongation and dentin thickening to the detriment of the pulp chamber that is gradually reduced in volume. Apexogenesis and apexification contribute to root formation. Defects and abnormal root formation implicate missing teeth(hypodontia), orteeth in excess (supernumary teeth or hyperdontia) or mis-shapped structures. Genetic defects (Nfic, Ptc, Dkk1, Osx, Smad4, and Wls) have been identified. Premature arrests of root formation are due to apical infection, radiation, chemotherapy, as well as genes alterations. Roots malformations include root dilacerations which are abnormal curvature of the root and sharp bend of the crown or root axis. Taurodontism and other misshaped root structures are also frequently seen in man. Two main forms have been recognized: 1) the CLCN7 encoding a chloride channel, and 2) the second related to a defective PLG gene (encoding plasminogen). Altogether, theses defects contribute to major endodontic difficulties.

Combined hepatoblastoma and yolk sac tumor of the liver

A 6-year-old patient was admitted to the Petrovsky National Research Center of Surgery in Moscow, diagnosed with hepatoblastoma (HB) of the right lobe of the liver and after undergoing 4 cycles of SIOPEL (super PLADO) pre-operative chemotherapy. An immunohistochemistry test, performed after liver resection, revealed a rare combination of mixed epithelial and mesenchymal hepatoblastoma and yolk sac tumor. The epithelial component of HB consisted of highly differentiated fetal cells, while the mesenchymal component consisted of osteoid. The morphological structure of the second lesion corresponded to yolk sac tumor. Both tumors had regressive changes conditioned by chemotherapy: these changes were most pronounced in HB. In the highly differentiated fetal component of HB it was possible to detect a weak focal perinuclear alpha-fetoprotein expression, HepPar expression, membranous expression of beta-catenin and diffuse glutamine synthetase expression. Mitotic figures were not determined. The node of the yolk sac tumor had the characteristic histological structure of an endodermal sinus tumor with a hepatoid component. In the main tumor node and its nodular elements in the fibrovascular stroma it was possible to identify alpha-fetoprotein expression, CD34, nuclear and cytoplasmic expression of beta-catenin, CDX2, as well as a rare expression of PLAP and multi-cytokeratin, and mitotic activity was high (21 in 10 high power fields, 400x magnification). In the existing literature available to us, there is only one observation of combined hepatoblastoma and yolk sac tumor. Parents patients agreed to use personal data, including the fotos, in research and publications.

Analysis of Epithelial Architecture and Planar Spindle Orientation in the Drosophila Wing Disc.

The Drosophila melanogaster wing imaginal disc is an epithelial sac that exhibits dramatic tissue growth during the larval stage. With its simple morphology and accessibility of genetic tools, studies using the wing disc have contributed to the understanding of the mechanisms of epithelial homeostasis including the control of mitotic spindle orientation. This chapter describes a detailed protocol for analyzing epithelial architecture and planar orientation of the mitotic spindle in the wing disc epithelium. The rapid dissection method, effective immunostaining, and mounting tips described here facilitate genetic and cell biological studies of the wing disc and can be applied to a wide array of studies using various Drosophila tissues.

Functional importance of an inverted formin C-terminal tail at morphologically dynamic epithelial junctions.

Epithelial cell-cell junctions have dual roles of accommodating morphological changes in an epithelium, while maintaining cohesion during those changes. An abundance of junction proteins has been identified, but many details on how intercellular junctions respond to morphological changes remain unclear. In Caenorhabditis elegans, the spermatheca is an epithelial sac that repeatedly dilates and constricts to allow ovulation. It is thought that the junctions between spermatheca epithelial cells undergo reversible partial unzipping to allow rapid dilation. Previously, we found that EXC-6, a C. elegans protein homolog of the human disease-associated formin INF2, is expressed in the spermatheca and promotes oocyte entry. We show here that EXC-6 localizes toward the apical aspect of the spermatheca epithelial junctions, and that the EXC-6-labeled junction domains "unzip" and dramatically flatten with oocyte entry into the spermatheca. We demonstrate that the C-terminal tail of EXC-6 is necessary and sufficient for junction localization. Moreover, expression of the tail alone worsens ovulation defects, suggesting this region not only mediates EXC-6 localization, but also interacts with other components important for junction remodeling.

Development of calcium bodies in Hylonsicus riparius (Crustacea: Isopoda)

Calcium bodies are internal epithelial sacs found in terrestrial isopods of the family Trichoniscidae that contain a mineralized extracellular matrix that is deposited and resorbed in relation to the molt cycle. Calcium bodies in several trichoniscids are filled with bacteria, the function of which is currently unknown. The woodlouse Hyloniscus riparius differs from other trichoniscids in that it possesses two different pairs of calcium bodies, the posterior pair being filled with bacteria and the anterior pair being devoid of bacteria. We explored the development of these organs and bacterial colonization of their lumen during the postmarsupial development with the use of optical clearing and whole-body confocal imaging of larval and juvenile stages. Our results show that calcium bodies are formed as invaginations of the epidermis in the region of intersegmental membranes during the postmarsupial development. The anterior pair of calcium bodies is generated during the first postmarsupial manca stage, whereas the posterior calcium bodies first appear in juveniles and are immediately colonized by bacteria, likely through a connection between the calcium body lumen and the body surface. Mineral is deposited in calcium bodies as soon as they are present.

Polyphosphate-accumulating bacterial community colonizing the calcium bodies of terrestrial isopod crustaceans Titanethes albus and Hyloniscus riparius.

Terrestrial isopods from the group Trichoniscidae accumulate calcium in specialized organs, known as the calcium bodies. These consist of two pairs of epithelial sacs located alongside the digestive system. These organs contain various forms of calcium and constantly present bacteria. To elucidate their origin and role, we analyzed the bacteria of the calcium bodies in the cave-dwelling isopod Titanethes albus and the epigean species Hyloniscus riparius, by microscopy, histochemistry, energy dispersive X-ray spectrometry, 16S rRNA analysis and in situ hybridization. The calcium bodies of both species comprise numerous and diverse bacterial communities consisting of known soil bacteria. Despite their diversity, these bacteria share the polyphosphate-accumulation ability. We present the model of phosphorous dynamics in the calcium bodies during the molting cycle and potentially beneficial utilization of the symbiotic phosphate by the host in cyclic regeneration of the cuticle. Although not fully understood, this unique symbiosis represents the first evidence of polyphosphate-accumulating bacterial symbionts in the tissue of a terrestrial animal.

The gap junction protein Innexin3 is required for eye disc growth in Drosophila

The Drosophila compound eye develops from a bilayered epithelial sac composed of an upper peripodial epithelium layer and a lower disc proper, the latter giving rise to the eye itself. During larval stages, complex signalling events between the layers contribute to the control of cell proliferation and differentiation in the disc. Previous work in our lab established the gap junction protein Innexin2 (Inx2) as crucial for early larval eye disc growth. By analysing the contribution of other Innexins to eye size control, we have identified Innexin3 (Inx3) as an important growth regulator. Depleting inx3 during larval eye development reduces eye size, while elevating inx3 levels increases eye size, thus phenocopying the inx2 loss- and gain-of-function situation. As demonstrated previously for inx2, inx3 regulates disc cell proliferation and interacts genetically with the Dpp pathway, being required for the proper activation of the Dpp pathway transducer Mad at the furrow and the expression of Dpp receptor Punt in the eye disc. At the developmental timepoint corresponding to eye disc growth, Inx3 colocalises with Inx2 in disc proper and peripodial epithelium cell membranes. In addition, we show that Inx3 protein levels critically depend on inx2 throughout eye development and that inx3 modulates Inx2 protein levels in the larval eye disc. Rescue experiments demonstrate that Inx3 and Inx2 cooperate functionally to enable eye disc growth in Drosophila. Finally, we demonstrate that expression of Inx3 and Inx2 is not only needed in the disc proper but also in the peripodial epithelium to regulate growth of the eye disc. Our data provide a functional demonstration that putative Inx2/Inx3 heteromeric channels regulate organ size.

Dual Role of Jun N-Terminal Kinase Activity in Bone Morphogenetic Protein-Mediated Drosophila Ventral Head Development.

The Drosophila bone morphogenetic protein encoded by decapentaplegic (dpp) controls ventral head morphogenesis by expression in the head primordia, eye-antennal imaginal discs. These are epithelial sacs made of two layers: columnar disc proper cells and squamous cells of the peripodial epithelium. dpp expression related to head formation occurs in the peripodial epithelium; cis-regulatory mutations disrupting this expression display defects in sensory vibrissae, rostral membrane, gena, and maxillary palps. Here we document that disruption of this dpp expression causes apoptosis in peripodial cells and underlying disc proper cells. We further show that peripodial Dpp acts directly on the disc proper, indicating that Dpp must cross the disc lumen to act. We demonstrate that palp defects are mechanistically separable from the other mutant phenotypes; both are affected by the c-Jun N-terminal kinase pathway but in opposite ways. Slight reduction of both Jun N-terminal kinase and Dpp activity in peripodial cells causes stronger vibrissae, rostral membrane, and gena defects than Dpp alone; additionally, strong reduction of Jun N-terminal kinase activity alone causes identical defects. A more severe reduction of dpp results in similar vibrissae, rostral membrane, and gena defects, but also causes mutant maxillary palps. This latter defect is correlated with increased peripodial Jun N-terminal kinase activity and can be caused solely by ectopic activation of Jun N-terminal kinase. We conclude that formation of sensory vibrissae, rostral membrane, and gena tissue in head morphogenesis requires the action of Jun N-terminal kinase in peripodial cells, while excessive Jun N-terminal kinase signaling in these same cells inhibits the formation of maxillary palps.

Mineral Deposition in Bacteria-Filled and Bacteria-Free Calcium Bodies in the Crustacean Hyloniscus riparius (Isopoda: Oniscidea)

Crustacean calcium bodies are epithelial sacs which contain a mineralized matrix. The objectives of this study were to describe the microscopic anatomy of calcium bodies in the terrestrial isopod Hyloniscus riparius and to establish whether they undergo molt-related structural changes. We performed 3D reconstruction of the calcium bodies from paraffin sections and analyzed their structure with light and electron microscopy. In addition, we analyzed the chemical composition of their mineralized matrices with micro-Raman spectroscopy. Two pairs of these organs are present in H. riparius. One pair is filled with bacteria while the other pair is not. In non-molting animals, the bacteria-filled calcium bodies contain apatite crystals and the bacteria-free calcium bodies enclose CaCO3-containing concretions with little organic matrix. During preparation for molt, an additional matrix layer is deposited in both pairs of calcium bodies. In the bacteria-filled calcium bodies it contains a mixture of calcium carbonate and calcium phosphate, whereas only calcium carbonate is present in bacteria-free calcium bodies. After ecdysis, all mineral components in bacteria-free calcium bodies and the additional matrix layer in bacteria-filled calcium bodies are completely resorbed. During calcium resorption, the apical surface of the calcium body epithelium is deeply folded and electron dense granules are present in spaces between epithelial cells. Our results indicate that the presence of bacteria might be linked to calcium phosphate mineralization. Calcium bodies likely provide a source of calcium and potentially phosphate for the mineralization of the new cuticle after molt. Unlike other terrestrial isopods, H. riparius does not form sternal CaCO3 deposits and the bacteria-free calcium bodies might functionally replace them in this species.

Calcium bodies of Titanethes albus (Crustacea: Isopoda): Molt-related structural dynamics and calcified matrix-associated bacteria

Crustaceans form a variety of calcium deposits in which they store calcium necessary for the mineralization of their exoskeletons. Calcium bodies, organs containing large amounts of calcium, have been reported in some terrestrial isopod crustaceans, but have not yet been extensively studied. We analyzed the architecture of these organs during the molt cycle in the isopod Titanethes albus. Two pairs of calcium bodies are positioned ventrolaterally in posterior pereonites of T. albus. Individual organs are epithelial sacs that contain material arranged in concentric layers delimited by thin laminae. As demonstrated by electron microscopy and fluorescence in situ hybridization, abundant bacteria are present within the calcium bodies. Regardless of the molt cycle stage, crystalline concretions are present in the central areas of the calcium bodies. Energy dispersive X-ray spectrometry of the concretions demonstrated that they are composed predominantly of calcium and phosphorus and selected area electron diffraction indicated the presence of hydroxyapatite. In molting animals, a glassy layer of mineralized matrix is formed between the envelope and the outermost lamina of the calcium body. This layer consists of an amorphous calcium mineral which contains less phosphorus than the central concretions and is resorbed after molt. Since changes in the mineralized matrix are synchronized with the molt cycle, the calcium bodies likely function as a storage compartment that complements sternal deposits as a source of calcium for the mineralization of the exoskeleton. Bacteria associated with the mineralized matrix of calcium bodies are evidently involved in calcium dynamics.

Dpp Signaling Activity Requires Pentagone to Scale with Tissue Size in the Growing Drosophila Wing Imaginal Disc

Author SummaryScaling, the fitting of pattern to size, manifests itself in numerous examples around us. During development, individual body parts scale up to fit the overall body size. Starved animals form smaller adults with proportionally smaller parts, and amphibian embryos can form normally proportioned adults after extreme surgical operations. How scaling is achieved is not well understood. Here, we establish the Drosophila wing imaginal disc, the precursor tissue of the adult wing, as a model to study scaling quantitatively during growth. In this model, we define scaling as the preservation of proportions of gene expression domains with tissue size during disc growth. The Decapentaplegic (Dpp) morphogen is known to play a central role in Drosophila wing formation and co-coordinately regulates growth and patterning. We found that as the disc grows, the Dpp response expands and scales with the tissue size. Interestingly, scaling is not perfect at all positions in the field. The scaling of the target gene domains is best where they have a function; Spalt, for example, scales best at the position in the anterior compartment where it helps to form one of the anterior veins of the wing. Analysis of mutants for pentagone, a transcriptional target of Dpp that encodes a secreted feedback regulator of the pathway, indicates that Pentagone plays a key role in scaling the Dpp gradient activity.

Exogen involves gradual release of the hair club fibre in the vibrissa follicle model

Exogen is a distinct phase of the hair cycle describing the process by which the hair club fibre is shed from the follicle. This process is difficult to study in human skin and little is known about the mechanisms involved in the release of club fibres. We sought an alternative model system to study exogen in more detail, and therefore utilised the vibrissa system on the rodent mystacial pad. The time at which a vibrissa club hair will be lost can be predicted, based on the relative lengths of the new growing fibre and old club fibre. This timing phenomenon was exploited to investigate the club fibre within the follicle as it approaches final release, revealing key changes in the adhesive state of the club fibre within the epithelial sac as it approached release. We propose that exogen should be subdivided to represent variations in the club fibre status.

Morphological and chemical description of the stylets of the red octopus, Enteroctopus megalocyathus (Mollusca: Cephalopoda)

This paper provides the first morphological and chemical description of the stylets (vestigial shell) of Enteroctopus megalocyathus, a large, commercially and ecologically important benthic species that is fished along the southern coasts of Argentina and Chile. The stylets are thin, semi-transparent curved structures embedded in the muscular tissue of the dorso-lateral regions of the mantle, and placed inside an epithelial sac. Rostral and post-rostral parts and a bend could be distinguished. Differences in the curvature of the post-rostral parts allow the discrimination of left and right stylets. In recent years these structures have received attention because of their potential use as a tool for age determination, based on interior growth rings. The elemental composition inside stylets can also assist in reconstructing environmental histories, and in determining dispersal and population structure. The length of the different parts and the maximum diameter at the bend were measured and compared between sexes and between left and right stylets. Transverse cuts were used to describe histological structures, the nucleus and the white core that surrounds it, and growth increments. Constituent chemical elements were analysed with a scanning electron microscope equipped with an X-ray energy-scattering microanalyzer. No significant differences between sexes were detected in the relative length of the post-rostral and rostral parts of the stylets. These relative lengths could, however, be of taxonomic value at the generic level. Two types of concentric increments were observed; the embryonic nucleus of the stylets was amorphous and did not present growth increments. The distribution of chemical elements in the stylets is also described.

Clinical and pathological analysis of primary lacrimal sac tumors

To investigate the clinical features and pathological classification of primary lacrimal sac tumors. A retrospective study of 96 cases of primary lacrimal sac tumors in past 50 years from EENT Hospital (Jan. 1956 to Dec. 2005) was performed to investigate the clinical features, radiological manifestation, histopathological classification and treatment. Primary lacrimal sac tumors were more common in men than in women (1.8:1.0) and the median age at presentation was 46 years (ranged 11 - 80 years). The most common sign and symptom were epiphora and lacrimal sac mass, respectively. Among these primary lacrimal sac tumors, 94.8% were malignant tumors (91/95). All epithelial lacrimal sac tumors (83 cases, 86.5%) were malignant and squamous cell carcinoma was the most common tumor (64 cases, 66.7%), followed by undifferentiated carcinoma (10 cases, 10.4%), mucoepidermoid carcinoma (4 cases, 4.2%), adenocarcinoma (4 cases, 4.2%) and transitional cell carcinoma (1 case, 1.0%). The nonepithelial tumors consisted of mucosa-associated lymphoid tissue (MALT) lymphoma (5 cases, 5.2%), melanoma (3 cases, 3.1%), neurilemoma (2 cases, 2.1%), hemangiopericytoma (2 cases, 2.1%) and cavernous hemangioma (1 case, 1.0%). Primary lacrimal sac tumors are extremely rare, but most of them are malignant tumors and are often misdiagnosed as dacryocystitis and lacrimal sac obstruction. Therefore, ophthalmologists should pay more attention to the diagnosis of lacrimal sac tumors.

Branching morphogenesis of the Drosophila tracheal system.

Many organs including the mammalian lung and vascular system consist of branched tubular networks that transport essential gases or fluids, but the genetic programs that control the development of these complex three-dimensional structures are not well understood. The Drosophila melanogaster tracheal (respiratory) system is a network of interconnected epithelial tubes that transports oxygen and other gases in the body and provides a paradigm of branching morphogenesis. It develops by sequential sprouting of primary, secondary, and terminal branches from an epithelial sac of approximately 80 cells in each body segment of the embryo. Mapping of the cell movements and shape changes during the sprouting process has revealed that distinct mechanisms of epithelial migration and tube formation are used at each stage of branching. Genetic dissection of the process has identified a general program in which a fibroblast growth factor (FGF) and fibroblast growth factor receptor (FGFR) are used repeatedly to control branch budding and outgrowth. At each stage of branching, the mechanisms controlling FGF expression and the downstream signal transduction pathway change, altering the pattern and structure of the branches that form. During terminal branching, FGF expression is regulated by hypoxia, ensuring that tracheal structure matches cellular oxygen need. A branch diversification program operates in parallel to the general budding program: Regional signals locally modify the general program, conferring specific structural features and other properties on individual branches, such as their substrate outgrowth preferences, differences in tube size and shape, and the ability to fuse to other branches to interconnect the network.

Label-retaining Cells in the Bulge Region are Directed to Cell Death after Plucking, Followed by Healing from the Surviving Hair Germ

Hair plucking is the most frequently used method of anagen induction within hair follicles. In this study, we found that plucking leads to the entire renewal of the follicular stem cell region of the mouse pelage follicle. Comparative histochemical analysis revealed that S100A4 protein was specifically distributed in the outer layer of the epithelial sac, which has been identified as the stem cell region of the pelage follicle, whereas the slow cycling cells that retained 5-bromo-2'-deoxyuridine label for 8 wk were located in the epithelial sac and also in the hair germ. Combined terminal deoxynucleotide transferase deoxyuridine triphosphate fluorescein nick end labeling method and immunohistochemistry revealed that positive cells were detected in the outer layer of the epithelial sac possessing both bromo-2'-deoxyuridine and S100A4 labels 4.5 h after plucking. No terminal deoxynucleotide transferase deoxyuridine triphosphate fluorescein nick end labeling signal, however, was observed in the hair germ. Serial inspection of the plucked follicle revealed that almost all regions of the epithelial sac became terminal deoxynucleotide transferase deoxyuridine triphosphate fluorescein nick end labeling positive 12 h after plucking. Terminal deoxynucleotide transferase deoxyuridine triphosphate fluorescein nick end labeling-positive cells ultimately degenerated without forming apoptotic bodies. Subsequently, the surviving label-retaining cells in the hair germ migrated upward to re-epithelialize the damaged portion. These results indicate that follicular stem cells in the epithelial sac underwent cell death after plucking. It is likely that the hair germ is responsible for the reconstruction of the stem cell region of the hair follicle.

Morphology and structural organization of Gene's organ in Argas walkerae.

Electron microscopy revealed that Gene's organ in females of Argas walkerae Kaiser & Hoogstraal (Ixodida: Argasidae) is formed as a double-sac structure consisting of an outer epithelial and an inner cuticular sac. The latter emerges through the camerostomal aperture to the exterior in ovipositing ticks. The epithelial sac forms the corpus and the two blind-ending horns, which pass into the epithelium of the excretory duct of a gland at each side of Gene's organ and envelop the cuticular sac. Both excretory ducts open into the lumen between the epithelial and the cuticular sac. The cuticular sac is folded and consists of a fibrous endocuticula outwards towards the lumen between the epithelial and the cuticular sac and of a smooth epicuticula inwards. Parallel running grooves occur over the lateral epicuticular surface turning medially into cobble-stone pavement-like rises. Tubuli pass through the cuticular sac ending in pores on the epicuticular surface and open into the lumen between the epithelial and the cuticular sac. Muscle fibres pass through the epithelial sac at the horn tips and are inserted to the cuticular sac. In ovipositing females, the glands are fully developed and the lumen between the epithelial and the cuticular sac is filled with an amorphous mass.