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Morphophysiological changes of the female prostate during pregnancy are still little known. Considering that this gland is highly influenced by steroid hormones, the aim of this study was to evaluate the impact of the pregnancy on female prostate morphophysiology in gerbils. Pregnant females were timed, and the prostates were analyzed at pregnancy days 6 (P6), 12 (P12), 18 (P18), and 24 (P24). Virgin females were used as the control group (C). We observed a profound change in the hormonal profile during gestation, which was marked by a high oscillation of the progesterone (P4) hormone. P4 serum levels increased, peaking at the middle of gestation, and decreased to the end of the pregnancy. The morphology of the gland in pregnant females also changed, being marked by an increase of acini lumen, and a decrease in stroma. Indeed, the acinar changes during pregnancy were followed by a significant reduction of the epithelial height, besides a change of the smooth muscle cells' morphology that became more relaxed. The number of progesterone receptor (PR) and androgen receptor (AR)-positives cells decreased with the increase of progesterone serum levels, showing an inverse relationship. Finally, we observed a reduction of epithelial proliferation and a significant increase of gland PAS-positive secretion at the end of pregnancy. Altogether, these results showed, for the first time, that the female prostate morphophysioloy is profoundly influenced by the gestational period, suggesting that the fluctuation of the P4 serum levels is the main factor influencing the gland during this period., (© 2021. Society for Reproductive Investigation.)

The origin of human metaplastic states and their propensity for cancer is poorly understood. Barrett's esophagus is a common metaplastic condition that increases the risk for esophageal adenocarcinoma, and its cellular origin is enigmatic. To address this, we harvested tissues spanning the gastroesophageal junction from healthy and diseased donors, including isolation of esophageal submucosal glands. A combination of single-cell transcriptomic profiling, in silico lineage tracing from methylation, open chromatin and somatic mutation analyses, and functional studies in organoid models showed that Barrett's esophagus originates from gastric cardia through c-MYC and HNF4A-driven transcriptional programs. Furthermore, our data indicate that esophageal adenocarcinoma likely arises from undifferentiated Barrett's esophagus cell types even in the absence of a pathologically identifiable metaplastic precursor, illuminating early detection strategies., (Copyright © 2021 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works.)

There is a prominent local raised pad called nuptial pad on the forelimb of Chinese brown frog (Rana dybowskii), which is hypothetically concluded as an enhancement of the grip and a spreader of pheromone during the amplexus. In this study, we investigated the immunolocalization and protein expression levels of AR, ERα, ERβ and aromatase in the nuptial pad of R. dybowskii during pre-hibernation and the breeding period. Histologically, the annual development of the nuptial pad in R. dybowskii is manifested as the larger area of specialized mucous gland and the longer length of papillary epidermal projection during the breeding period. AR, ERα, ERβ and aromatase are present in the stratum granulosum, stratum spinosum, stratum basale and the secretory portion of specialized mucous glands during both periods. Western blotting results confirmed that AR, ERα and ERβ protein levels are higher during pre-hibernation than those during the breeding season. These results suggest that nuptial pad is the direct target organ of androgen and estrogen. Androgen may participate in the regulation of annual development and glandular function of nuptial pad, and estrogen may play an endocrine, autocrine or paracrine role during pre-hibernation and the breeding period.

A central goal in biology is to determine the ways in which evolution repeats itself. One of the most remarkable examples in nature of convergent evolutionary novelty is animal venom. Across diverse animal phyla, various specialized organs and anatomical structures have evolved from disparate developmental tissues to perform the same function, that is, produce and deliver a cocktail of potent molecules to subdue prey or predators. Venomous organisms therefore offer unique opportunities to investigate the evolutionary processes of convergence of key adaptive traits, and the molecular mechanisms underlying the emergence of novel genes, cells, and tissues. Indeed, some venomous species have already proven to be highly amenable as models for developmental studies, and recent work with venom gland organoids provides manipulatable systems for directly testing important evolutionary questions. Here, we provide a synthesis of the current knowledge that could serve as a starting point for the establishment of venom systems as new models for evolutionary and molecular biology. In particular, we highlight the potential of various venomous species for the study of cell differentiation and cell identity, and the regulatory dynamics of rapidly evolving, highly expressed, tissue-specific, gene paralogs. We hope that this review will encourage researchers to look beyond traditional study organisms and consider venom systems as useful tools to explore evolutionary novelties., (© The Author(s) 2020. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Calcium (Ca 2+ ) and cyclic AMP (cAMP) signaling cross talk and synergize to stimulate the cardinal functions of exocrine cells, regulated exocytosis, and fluid and electrolyte secretion. This physiological process requires the organization of the two signaling pathways into complexes at defined cellular domains and close placement. Such domains are formed by membrane contact sites (MCS). This review discusses the basic properties of Ca 2+ signaling in exocrine cells, the role of MCS in the organization of cell signaling and in cross talk and synergism between the Ca 2+ and cAMP signaling pathways and, finally, the mechanism by which the Ca 2+ and cAMP pathways synergize to stimulate epithelial fluid and electrolyte secretion., (Copyright © 2020 Cold Spring Harbor Laboratory Press; all rights reserved.)

The molluscan larval shell formation is a complicated process. There is evidence that the mantle of the primary larva (trochophore) contains functionally different cell populations with distinct gene expression profiles. However, it remains unclear how these cells are specified. In the present study, we identified three cell populations from the shell gland in earlier stages (gastrula) from the bivalve mollusc Crassostrea gigas. These cell populations were determined by analyzing the co-expression relationships among six potential shell formation (pSF) genes using two-color hybridization. The three cell populations, which we designated as SGCPs (shell gland cell populations), formed a concentric-circle pattern from outside to inside of the shell gland. SGCP I was located in the outer edge of the shell gland and the cells expressed pax2/5/8, gata2/3, and bmp2/4. SGCP II was located more internally and the cells expressed two engrailed genes. The last population, SGCP III, was located in the central region of the shell gland and the cells expressed lox4. Determination of the gene expression profiles of SGCPs would help trace their origins and fates and elucidate how these cell populations are specified. Moreover, potential roles of the SGCPs, e.g., development of sensory cells and shell biogenesis, are suggested. Our results reveal the internal organization of the embryonic shell gland at the molecular level and add to the knowledge of larval shell formation.

Excretory and secretory products are crucial for parasite infectivity and host immunomodulation, but the functioning and ultrastructure of the excretory gland cell (EC) that produces these products are still scarcely understood and described. In light of growing reports on anisakiasis cases in Europe, we aimed to characterise the EC of larval Anisakis pegreffii and adult Pseudoterranova azarasi . In the latter, EC starts 0.85 mm from the head tip, measuring 1.936 × 0.564 mm. Larval EC shows a long nucleus with thorn-like extravaginations toward the cytoplasm, numerous electron-dense and -lucent secretory granules spanning from the perinuclear to subplasmalemmal space, an elevated number of free ribosomes, small, spherical mitochondria with few cristae and a laminated matrix, small and few Golgi apparatuses, and few endoplasmic reticula, with wide cisternae complexes. Ultrastructure suggests that anaerobic glycolysis is the main metabolic pathway, obtained through nutrient endocytosis across the pseudocoelomic surface of the EC plasmalemma and its endocytic canaliculi. Thorn-like extravaginations of EC karyotheca likely mediate specific processes (Ca 2+ signaling, gene expression, transport, nuclear lipid metabolism) into the extremely wide EC cytosol, enabling focal delivery of a signal to specific sites in a short time. These functional annotations of parasitic EC should help to clarify anisakiasis pathogenesis., Competing Interests: The authors declare no conflict of interest.

Background: Aquatic species in several clades possess cement glands producing adhesive secretions of various strengths. In vertebrates, transient adhesive organs have been extensively studied in Xenopus laevis, other anurans, and in several fish species. However, the development of these structures is not fully understood., Results: Here, we report on the development and functional morphology of the adhesive gland of a giant danio species, Devario malabaricus. We found that the gland is localized on the larval head, is composed of goblet-like secretory cells framed by basal, bordering, and intercalated apical epithelial cells, and is innervated by the trigeminal ganglion. The gland allows nonswimming larvae to adhere to various substrates. Its secretory cells differentiate by 12 hours postfertilization and begin to disappear in the second week of life. Exogenous retinoic acid disrupts the gland's patterning. More importantly, the single mature gland emerges from fusion of two differentiated secretory cells fields; this fusion is dependent on nonmuscle myosin II function., Conclusions: Taken together, our studies provide the first documentation of the embryonic development, structure, and function of the adhesive apparatus of a danioninae. To our knowledge, this is also the first report of a cement gland arising from convergence of two bilateral fields., (© 2019 Wiley Periodicals, Inc.)

The silkworm Bombyx mori is a well-characterized model organism for studying the silk gland development and silk production process. Using positional cloning and gene sequencing, we have previously reported that a truncated fibroin heavy chain was responsible for silkworm naked pupa (Nd) mutant. However, the mechanisms by which the mutant FibH causes developmental defects and secretion-deficiency of the silk gland remain to be fully elucidated. Here, silk gland's developmental features, histomorphology, and transcriptome analyses were used to characterize changes in its structure and gene expression patterns between Nd mutant and WT/Dazao. Whole larval stage investigation showed that Nd-PSG undergoes an arrested/delayed development, which eventually resulted in a gland degeneration. By using section staining and transmission electron microscope, a blockade in intracellular vesicle transport from endoplasmic reticulum to Golgi apparatus (secretion-deficiency) and an increased number of autophagosomes and lysosomes were found in Nd-PSG's cytoplasm. Next, by using RNA sequencing and comparative transcriptomic analysis, 2178 differentially expressed genes were identified between Nd-PSG and WT-PSG, among which most of the DEGs associated with cellular stress responses (autophagy, ubiquitin-proteasome system, and heat shock response) were significantly up-regulated in Nd-PSG, suggesting that mutant FibH perturbed cellular homeostasis and resulted in an activation of adaptive responses in PSG cells. These findings reveal the molecular mechanism of the Naked pupa (Nd) mutation and provide insights into silk gland development as well as silk protein production in silkworm Bombyx mori., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

Hagfishes use their defensive slime to ward off gill-breathing predators. Slime gland refilling is a surprisingly slow process, and previous research has shown that the composition of the slime exudate changes significantly during refilling, which likely has consequences for the functionality of the slime. This study set out to expand our understanding of slime gland refilling by examining the cellular processes involved in refilling of the glands, as well as determining where in the gland the main slime cells - the gland thread cells and gland mucous cells - arise. Slime glands were electro-stimulated to exhaust their slime stores, left to refill for set periods of time, and harvested for histological and immunohistochemical examination. Whole slime glands, gland thread cell morphometrics and slime cell proportions were examined over the refilling cycle. Slime glands decreased significantly in size after exhaustion, but steadily increased in size over refilling. Gland thread cells were the limiting factor in slime gland refilling, taking longer to replenish and mature than gland mucous cells. Newly produced gland thread cells underwent most of their growth near the edge of the gland, and larger cells were found farthest from the edge of the gland. Immunohistochemical analysis also revealed proliferating cells only within the epithelial lining of the slime gland, suggesting that new slime cells originate from undifferentiated cells lining the gland. Our results provide an in-depth look at the cellular dynamics of slime gland refilling in Pacific hagfish, and provide a model for how slime glands refill at the cellular level., Competing Interests: Competing interestsThe authors declare no competing or financial interests., (© 2018. Published by The Company of Biologists Ltd.)

Pheromones, low molecular weight chemical entities that bind to pheromone carrier proteins, are chemical signals that play an important role in the communication system in animals. This has been rather fairly well-studied in the rodents. The preputial gland, a rich source of pheromones in many rodents, contains a low molecular mass protein (18-20 kDa) that acts as one such pheromone carrier. However, the presence of this protein in the notorious rodent pest Millardia meltada has not yet been proven. Therefore, we aimed at identifying this protein, and the pheromones that are bound to it, in this rodent so as to utilize the information in the control of this pest. Twenty volatile compounds were identified in the preputial gland using GC-MS. Total protein of the gland was fractioned by both one and two-dimensional electrophoresis when we identified a low molecular mass protein (19 kDa, pI-4.7). Adopting MALDI-TOF MS and LC-MS analyses, the protein was confirmed as α 2u-globulin. To identify the volatiles bound to this protein, we used column chromatography and GC-MS. We found that farnesol and 6-methyl-1-heptanol are the volatiles that would bind to the protein, which we propose to be putative pheromones. Immunohistochemical analysis confirmed localization of α 2u-globulin in the acinar cells of the preputial gland. Thus, we show that α 2u-globulin, a pheromone-carrier protein, is present in the preputial gland acinar cells of M. meltada and suggest farnesol and 6-methyl-1-heptanol to be the volatiles which would bind to it. The α 2u-globulin together with farnesol and 6-methyl-1-heptanol contribute to pheromonal communication of M. meltada., Competing Interests: The authors have declared that no competing interests exist.

Cells demonstrate plasticity following injury, but the extent of this phenomenon and the cellular mechanisms involved remain underexplored. Using single-cell RNA sequencing (scRNA-seq) and lineage tracing, we uncover that myoepithelial cells (MECs) of the submucosal glands (SMGs) proliferate and migrate to repopulate the airway surface epithelium (SE) in multiple injury models. Specifically, SMG-derived cells display multipotency and contribute to basal and luminal cell types of the SMGs and SE. Ex vivo expanded MECs have the potential to repopulate and differentiate into SE cells when grafted onto denuded airway scaffolds. Significantly, we find that SMG-like cells appear on the SE of both extra- and intra-lobular airways of large animal lungs following severe injury. We find that the transcription factor SOX9 is necessary for MEC plasticity in airway regeneration. Because SMGs are abundant and present deep within airways, they may serve as a reserve cell source for enhancing human airway regeneration., (Copyright © 2018 Elsevier Inc. All rights reserved.)

The mouse trachea is thought to contain two distinct stem cell compartments that contribute to airway repair-basal cells in the surface airway epithelium (SAE) and an unknown submucosal gland (SMG) cell type. Whether a lineage relationship exists between these two stem cell compartments remains unclear. Using lineage tracing of glandular myoepithelial cells (MECs), we demonstrate that MECs can give rise to seven cell types of the SAE and SMGs following severe airway injury. MECs progressively adopted a basal cell phenotype on the SAE and established lasting progenitors capable of further regeneration following reinjury. MECs activate Wnt-regulated transcription factors (Lef-1/TCF7) following injury and Lef-1 induction in cultured MECs promoted transition to a basal cell phenotype. Surprisingly, dose-dependent MEC conditional activation of Lef-1 in vivo promoted self-limited airway regeneration in the absence of injury. Thus, modulating the Lef-1 transcriptional program in MEC-derived progenitors may have regenerative medicine applications for lung diseases., (Copyright © 2018 Elsevier Inc. All rights reserved.)

The venom gland is a ubiquitous organ in Hymenoptera. In insect parasitoids, the venom gland has been shown to have multiple functions including regulation of host immune response, host paralysis, host castration and developmental alteration. However, the role played by the venom gland has been mainly studied in parasitoids developing in larval or pupal hosts while little is known for parasitoids developing in insect eggs. We conducted the first extensive characterization of the venom of the endoparasitoid Ooencyrtus telenomicida (Vassiliev), a species that develops in eggs of the stink bug Nezara viridula (L.). In particular we investigated the structure of the venom apparatus, its functional role and conducted a transcriptomic analysis of the venom gland. We found that injection of O. telenomicida venom induces: 1) a melanized-like process in N. viridula host eggs (host-parasitoid interaction), 2) impairment of the larval development of the competitor Trissolcus basalis (Wollaston) (parasitoid-parasitoid interaction). The O. telenomicida venom gland transcriptome reveals a majority of digestive enzymes (peptidases and glycosylases) and oxidoreductases (laccases) among the most expressed genes. The former enzymes are likely to be involved in degradation of the host resources for the specific benefit of the O. telenomicida offspring. In turn, alteration of host resources caused by these enzymes may negatively affect the larval development of the competitor T. basalis. We hypothesize that the melanization process induced by venom injection could be related to the presence of laccases, which are multicopper oxidases that belong to the phenoloxidases group. This work contributed to a better understanding of the venom in insect parasitoids and allowed to identify candidate genes whose functional role can be investigated in future studies., (Copyright © 2018 Elsevier Ltd. All rights reserved.)

Besides the common labial and metapleural glands, four novel exocrine glands are described in the thorax of both workers and queens of the ponerine ant Myopias hollandi. From anterior to posterior, these glands were designated as the propleural pit gland, the posterolateral pronotal gland, the anterolateral propodeal gland and the metasternal process gland. They all correspond with class-3 glands, that are made up of bicellular units that each comprise a secretory cell and a duct cell. In the propleural pit gland, the ducts are characterized by a gradually widening diameter, while in the three other glands the ducts show a portion which displays a balloon-like expansion, that on semithin sections stains very dark. For none of these novel glands the function is known as yet, although ultrastructural examination indicates that they produce a non-proteinaceous and therefore possibly pheromonal secretion., (Copyright © 2018 Elsevier Ltd. All rights reserved.)

The honeybee (Apis mellifera L.) uses various chemical signals produced by the worker exocrine glands to maintain the functioning of its colony. The roles of worker postcerebral glands (PcGs), thoracic glands (TGs), and mandibular glands (MGs) and the functional changes they undergo according to the division of labor from nursing to foraging are not as well studied. To comprehensively characterize the molecular roles of these glands in workers and their changes according to the division of labor of workers, we analyzed the proteomes of PcGs, TGs, and MGs from nurse bees and foragers using shotgun proteomics technology. We identified approximately 2000 proteins from each of the nurse bee or forager glands and highlighted the features of these glands at the molecular level by semiquantitative enrichment analyses of frequently detected, gland-selective, and labor-selective proteins. First, we found the high potential to produce lipids in PcGs and MGs, suggesting their relation to pheromone production. Second, we also found the proton pumps abundant in TGs and propose some transporters possibly related to the saliva production. Finally, our data unveiled candidate enzymes involved in labor-dependent acid production in MGs.

Wnt signaling is required for lineage commitment of glandular stem cells (SCs) during tracheal submucosal gland (SMG) morphogenesis from the surface airway epithelium (SAE). Whether similar Wnt-dependent processes coordinate SC expansion in adult SMGs following airway injury remains unknown. We found that two Wnt-reporters in mice (BAT-gal and TCF/Lef:H2B-GFP) are coexpressed in actively cycling SCs of primordial glandular placodes and in a small subset of adult SMG progenitor cells that enter the cell cycle 24 hours following airway injury. At homeostasis, these Wnt reporters showed nonoverlapping cellular patterns of expression in the SAE and SMGs. Following tracheal injury, proliferation was accompanied by dynamic changes in Wnt-reporter activity and the analysis of 56 Wnt-related signaling genes revealed unique temporal changes in expression within proximal (gland-containing) and distal (gland-free) portions of the trachea. Wnt stimulation in vivo and in vitro promoted epithelial proliferation in both SMGs and the SAE. Interestingly, slowly cycling nucleotide label-retaining cells (LRCs) of SMGs were spatially positioned near clusters of BAT-gal positive serous tubules. Isolation and culture of tet-inducible H2B-GFP LRCs demonstrated that SMG LRCs were more proliferative than SAE LRCs and culture expanded SMG-derived progenitor cells outcompeted SAE-derived progenitors in regeneration of tracheal xenograft epithelium using a clonal analysis competition assay. SMG-derived progenitors were also multipotent for cell types in the SAE and formed gland-like structures in xenografts. These studies demonstrate the importance of Wnt signals in modulating SC phenotypes within tracheal niches and provide new insight into phenotypic differences of SMG and SAE SCs. Stem Cells 2016;34:2758-2771., (© 2016 AlphaMed Press.)

The molt-intermolt cycle is an essential feature in holometabolous and hemimetabolous insects' development. In the silkworm, silk glands are under dramatic morphological and functional changes with fibroin genes' transcription being repeatedly turned off and on during the molt-intermolt cycles. However, the molecular mechanisms controlling it are still unknown. Here, silk gland's histomorphology and transcriptome analysis were used to characterize changes in its structure and gene expression patterns from molt to intermolt stages. By using section staining and transmission electron microscope, a renewable cell damage was detected in the silk gland at the molt stage, and an increased number of autophagosomes and lysosomes were found in silk gland cells' cytoplasm. Next, by using RNA sequencing, 54,578,413 reads were obtained, of which 85% were mapped to the silkworm reference genome. The expression level analysis of silk protein genes and silk gland transcription factors revealed that fibroin heavy chain, fibroin light chain, P25/fhx, sericin1, sericin3 and Dimm had consistent alteration trends in temporal expression. In addition, differentially expressed genes (DEGs) were identified, and most of the DEGs associated with ecdysone signal transduction, mRNA degradation, protein proteolysis, and autophagy were significantly down-regulated in the transition from molt to intermolt, suggesting that these pathways were activated for the silk gland renewal. These findings provide insights into the molecular mechanisms of silk gland development and silk protein genes transcriptional regulation during the molt to intermolt transition process., (Copyright © 2016 Elsevier Ltd. All rights reserved.)

A promising approach to new diabetes therapies is to generate β cells from other differentiated pancreatic cells in vivo. Because the acinar cells represent the most abundant cell type in the pancreas, an attractive possibility is to reprogram acinar cells into β cells. The transcription factor Pdx1 (Pancreas/duodenum homeobox protein 1) is essential for pancreatic development and cell lineage determination. Our objective is to examine whether exogenous expression of Pdx1 in acinar cells of adult mice might induce reprogramming of acinar cells into β cells. We established a transgenic mouse line in which Pdx1 and EGFP (enhanced green fluorescent protein) could be inducibly expressed in the acinar cells. After induction of Pdx1, we followed the acinar cells for their expression of exocrine and endocrine markers using cell-lineage tracing with EGFP. The acinar cell-specific expression of Pdx1 in adult mice reprogrammed the acinar cells as endocrine precursor cells, which migrated into the pancreatic islets and differentiated into insulin-, somatostatin-, or PP (pancreatic polypeptide)-producing endocrine cells, but not into glucagon-producing cells. When the mice undergoing such pancreatic reprogramming were treated with streptozotocin (STZ), the newly generated insulin-producing cells were able to ameliorate STZ-induced diabetes. This paradigm of in vivo reprogramming indicates that acinar cells hold promise as a source for new islet cells in regenerative therapies for diabetes.

The excretory system of the nematode Caenorhabditis elegans is a superb model of tubular organogenesis involving a minimum of cells. The system consists of just three unicellular tubes (canal, duct, and pore), a secretory gland, and two associated neurons. Just as in more complex organs, cells of the excretory system must first adopt specific identities and then coordinate diverse processes to form tubes of appropriate topology, shape, connectivity, and physiological function. The unicellular topology of excretory tubes, their varied and sometimes complex shapes, and the dynamic reprogramming of cell identity and remodeling of tube connectivity that occur during larval development are particularly fascinating features of this organ. The physiological roles of the excretory system in osmoregulation and other aspects of the animal's life cycle are only beginning to be explored. The cellular mechanisms and molecular pathways used to build and shape excretory tubes appear similar to those used in both unicellular and multicellular tubes in more complex organs, such as the vertebrate vascular system and kidney, making this simple organ system a useful model for understanding disease processes., (Copyright © 2016 by the Genetics Society of America.)

Silk is a protein of interest to both biological and industrial sciences. The silkworm, Bombyx mori, forms this protein into strong threads starting from soluble silk proteins using a number of biochemical and physical cues to allow the transition from liquid to fibrous silk. A pH gradient has been measured along the gland, but the methodology employed was not able to precisely determine the pH at specific regions of interest in the silk gland. Furthermore, the physiological mechanisms responsible for the generation of this pH gradient are unknown. In this study, concentric ion selective microelectrodes were used to determine the luminal pH of B. mori silk glands. A gradient from pH 8.2 to 7.2 was measured in the posterior silk gland, with a pH 7 throughout the middle silk gland, and a gradient from pH 6.8 to 6.2 in the beginning of the anterior silk gland where silk processing into fibers occurs. The small diameter of the most anterior region of the anterior silk gland prevented microelectrode access in this region. Using a histochemical method, the presence of active carbonic anhydrase was identified in the funnel and anterior silk gland of fifth instar larvae. The observed pH gradient collapsed upon addition of the carbonic anhydrase inhibitor methazolamide, confirming an essential role for this enzyme in pH regulation in the B. mori silk gland. Plastic embedding of whole silk glands allowed clear visualization of the morphology, including the identification of four distinct epithelial cell types in the gland and allowed correlations between silk gland morphology and silk stages of assembly related to the pH gradient. B. mori silk glands have four different epithelial cell types, one of which produces carbonic anhydrase. Carbonic anhydrase is necessary for the mechanism that generates an intraluminal pH gradient, which likely regulates the assembly of silk proteins and then the formation of fibers from soluble silk proteins. These new insights into native silk formation may lead to a more efficient production of artificial or regenerated silkworm silk fibers., (Copyright © 2015 Elsevier Ltd. All rights reserved.)

Amphibians have evolved a wide variety of mechanisms that provide a certain degree of protection against predators, including camouflage, tail autonomy, encounter behavior and noxious or toxic skin secretions. In addition to these strategies, some amphibians release a glue-like secretion onto the surface of their skin when threatened. While some information regarding the origin and production of these adhesive secretions is available for frogs such as Notaden bennetti, these aspects are only partially understood in salamanders. We contribute to an earlier study and provide additional information regarding the origin, production, and characterization of the adhesive secretion in the red-legged salamander (Plethodon shermani) at a microanatomical level. When stressed, this salamander secretes a milky, viscous liquid from its dorsal and ventral skin. This secretion is extremely adhesive and hardens within seconds upon exposure to air. This study describes two cutaneous gland types (mucous and granular) in the dorsal and ventral epithelial tissue that differ considerably in their secretory content. While the smaller mucous glands contains flocculent to granular material, mostly acidic glycoproteins, the granular glands synthesize various granules of differing size and density that consist of basic proteinaceous material. The results strongly indicate that the secretions of both gland types from the dorsal as well as the ventral side form the adhesive mucus in Plethodon shermani, consisting of basic and acidic glycoproteins, glycoconjugates with mannose and α-L-fucose residues as well as lipid components., (Copyright © 2015 Elsevier GmbH. All rights reserved.)

The paradigm saying that release of the brain neuropeptide big prothoracicotropic hormone (PTTH) initiates metamorphosis by activating the Torso-receptor/ERK pathway in larval prothoracic glands (PGs) is widely accepted nowadays. Upon ligand-receptor interaction Ca(2+) enters the PG cells and acts as a secondary messenger. Ecdysteroidogenesis results, later followed by apoptosis. Yet, some data do not fit in this model. In some species decapitated animals can still molt, even repeatedly, and metamorphose. PTTH does not universally occur in all insect species. PGs may also have other functions; PGs as counterpart of the vertebrate thymus? There are also small PTTHs. Finally, PTTH remains abundantly present in adults and plays a role in control of ecdysteroidogenesis (=sex steroid production) in gonads. This is currently documented only in males. This urges a rethinking of the PTTH-PG paradigm. The key question is: Why does PTTH-induced Ca(2+) entry only result in ecdysteroidogenesis and apoptosis in specific cells/tissues, namely the PGs and gonads? Indeed, numerous other neuropeptides also use Ca(2+) as secondary messenger. The recent rediscovery that in both invertebrates and vertebrates at least some isoforms of Ca(2+)-ATPase need the presence of an endogenous farnesol/juvenile hormone(JH)-like sesquiterpenoid for keeping cytosolic [Ca(2+)]i below the limit of apoptosis-induction, triggered the idea that it is not primarily PTTH, but rather the drop to zero of the JH titer that acts as the primordial initiator of metamorphosis by increasing [Ca(2+)]i. PTTH likely potentiates this effect but only in cells expressing Torso. PTTH: an evolutionarily ancient gonadotropin?, (Copyright © 2014 Elsevier Inc. All rights reserved.)

Hyperplasia/hypertrophy of submucosal glands contributes to mucus overproduction in chronic diseases of the upper and lower respiratory tracts, especially in adult and pediatric chronic rhinosinusitis. Mechanisms that lead to glandular hyperplasia/hypertrophy are markedly understudied, reflecting a lack of in vitro model systems wherein airway epithelial progenitor cells differentiate into glandular cells. In this study, we developed and compared several in vitro three-dimensional systems using human nasal epithelial basal cells (HNEBCs) cultured by different methods on two types of extracellular matrices. We demonstrate that HNEBCs cultured on Matrigel (Corning, Tewksbury, MA) form glandular acini-like structures, whereas HNEBCs embedded in a collagen type I matrix form a network of tubules. Fibroblast-conditioned medium increases tubule formation in collagen type I. In contrast, HNEBCs cocultured with fibroblasts self-aggregate into organotypic structures with tubules and acini. These observations provide morphological evidence that HNEBCs are pluripotent and retain the capacity to differentiate into structures resembling specific structural components of submucosal glands depending on the extracellular matrices and culture conditions. The resultant models should prove useful in targeting cross-talk between epithelial cells and fibroblasts to decipher molecular mechanisms and specific signals responsible for the development of glandular hyperplasia/hypertrophy, which in turn may lead to new therapeutic strategies for chronic rhinosinusitis and other inflammatory respiratory diseases characterized by glandular hyperplasia/hypertrophy.

Epithelial gland systems play an important role in marine molluscs in fabricating lubricants, repellents, fragrances, adhesives or enzymes. In cephalopods the typically single layered epithelium provides a highly dynamic variability and affords a rapid rebuilding of gland cells. While the digestive hatching gland (also named Hoyle organ) is obligatory for most cephalopods, only four genera (Nautilus, Sepia, Euprymna and Idiosepius) produce adhesive secretions by means of glandular cells in an adhesive area on the mantle or tentacles. In Idiosepius this adhesive organ is restricted to the posterior part of the fin region on the dorsal mantle side and well developed in the adult stage. Two gland cell types could be distinguished, which produce different contents of the adhesive. During the embryonic development the same body area is occupied by the temporary hatching gland. The question arises, in which way the hatching gland degrades and is replaced by the adhesive gland. Ultrastructural analyses as well as computer tomography scans were performed to monitor the successive post hatching transformation in the mantle epithelium from hatching gland degradation to the formation of the adhesive organ. According to our investigations the hatching gland cells degrade within about 1 day after hatching by a type of programmed cell death and leave behind a temporary cellular gap in this area. First glandular cells of the adhesive gland arise 7 days after hatching and proceed evenly over the posterior mantle epithelium. In contrast, the accompanying reduction of a part of the dorsal mantle musculature is already established before hatching. The results demonstrate a distinct independence between the two gland systems and illustrate the early development of the adhesive organ as well as the corresponding modifications within the mantle., (Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.)

Hagfishes thwart attacks by fish predators by producing liters of defensive slime. The slime is produced when slime gland exudate is released into the predator's mouth, where it deploys in a fraction of a second and clogs the gills. Slime exudate is composed mainly of secretory products from two cell types, gland mucous cells and gland thread cells, which produce the mucous and fibrous components of the slime, respectively. Here, we review what is known about the composition of the slime, morphology of the slime gland, and physiology of the cells that produce the slime. We also discuss several of the mechanisms involved in the deployment of both mucous and thread cells during the transition from thick glandular exudate to ultradilute material. We review biomechanical aspects of the slime, along with recent efforts to produce biomimetic slime thread analogs, and end with a discussion of how hagfish slime may have evolved.

The appendicularian, Oikopleura dioica, is a planktonic chordate. Its simple and transparent body, invariant cell lineages and short life cycle of 5 days make it a promising model organism for studies of chordate development. Here we describe the cell migration that occurs during development of the O. dioica larva. Using time-lapse imaging facilitated by florescent labeling of cells, three cell populations exhibiting long-distance migration were identified and characterized. These included (i) a multinucleated oral gland precursor that migrates anteriorly within the trunk region and eventually separates into the left and right sides, (ii) endodermal strand cells that are collectively retracted from the tail into the trunk in a tractor movement, and (iii) two subchordal cell precursors that individually migrate out from the trunk to the tip of the tail. The migration of subchordal cell precursors starts when all of the endodermal strand cells enter the trunk, and follows the same path but in a direction opposite to that of the latter. Labeling of these cells with a photoconvertible fluorescent protein, Kaede, demonstrated that the endodermal strand cells and subchordal cell precursors have distinct origins and eventual fates. Surgical removal of the trunk from the tail demonstrated that the endodermal strand cells do not require the trunk for migration, and that the subchordal cell precursors would be attracted by the distal part of the tail. This well-defined, invariant and traceable long-distance cell migration provides a unique experimental system for exploring the mechanisms of versatile cell migration in this simple organism with a chordate body plan., (Copyright © 2014 Elsevier Inc. All rights reserved.)

Social insects possess a rich set of exocrine organs producing diverse pheromones and defensive compounds. This is especially true for termite imagoes, which are equipped with several glands producing, among others, sex pheromones and defensive compounds protecting imagoes during the dispersal flight and colony foundation. Here, we describe the clypeal gland, a new termite exocrine organ occurring in the labro-clypeal region of imagoes of most Rhinotermitidae, Serritermitidae and Termitidae species. The clypeal gland of Coptotermes testaceus consists of class 1 (modified epidermal cell) and class 3 (bicellular gland unit) secretory cells. Ultrastructural features suggest that the gland secretes volatile compounds and proteins, probably after starting the reproduction. One peculiar feature of the gland is the presence of multiple secretory canals in a single canal cell, a feature never observed before in other insect glands. Although the function of the gland remains unknown, we hypothesize that it could produce secretion signalling the presence of functional reproductives or their need to be fed., (Copyright © 2014 Elsevier Ltd. All rights reserved.)

Snake venom metalloproteinases (SVMPs) are zinc-dependent enzymes responsible for most symptoms of human envenoming. Like matrix metalloproteinases (MMPs) and a disintegrin and metalloproteinase (ADAM) proteins, SVMPs are synthesized as zymogens, and enzyme activation is regulated by hydrolysis of their prodomain, but the processing of SVMPs is still unclear. In this study, we attempted to identify the presence of prodomain in different compartments of snake venom glands as zymogens or in the free form to elucidate some mechanism involved in SVMP activation. Using antibodies obtained by immunization with a recombinant prodomain, bands of zymogen molecular mass and prodomain peptides were detected mostly in gland extracts all along the venom production cycle and in the venom collected from the lumen at the peak of venom production. Prodomain was detected in secretory cells mostly in the secretory vesicles near the Golgi. We hypothesize that the processing of SVMPs starts within secretory vesicles and continues in the lumen of the venom gland just after enzyme secretion and involves different steps compared to ADAMs and MMPs but can be used as a model for studying the relevance of peptides resulting from prodomain processing and degradation for controlling the activity of metalloproteinases.

Cytoplasmic Ca(2+) is a master regulator of airway physiology; it controls fluid, mucus, and antimicrobial peptide secretion, ciliary beating, and smooth muscle contraction. The focus of this review is on the role of cytoplasmic Ca(2+) in fluid secretion by airway exocrine secretory cells. Airway submucosal gland serous acinar cells are the primary fluid secreting cell type of the cartilaginous conducting airways, and this review summarizes the current state of knowledge of the molecular mechanisms of serous cell ion transport, with an emphasis on their regulation by intracellular Ca(2+). Many neurotransmitters that regulate secretion from serous acinar cells utilize Ca(2+) as a second messenger. Changes in intracellular Ca(2+) concentration regulate the activities of ion transporters and channels involved in transepithelial ion transport and fluid secretion, including Ca(2+)-activated K(+) channels and Cl(-) channels. We also review evidence of interactions of Ca(2+) signaling with other signaling pathways (cAMP, NO) that impinge upon different ion transport pathways, including the cAMP/PKA-activated cystic fibrosis (CF) transmembrane conductance regulator (CFTR) anion channel. A better understanding of Ca(2+) signaling and its targets in airway fluid secretion may identify novel strategies to intervene in airway diseases, for example to enhance fluid secretion in CF airways., (Copyright © 2014 Elsevier Ltd. All rights reserved.)

Geophis belongs to the goo-eating dipsadine assemblage of snakes that are known to feed exclusively on earthworms, snails, and slugs. Although the unusual feeding strategies of the goo-eating dipsadines are well known (but poorly documented), little attention has been paid to their internal anatomy. Here, we describe a new and noteworthy morphological and histochemical condition of the infralabial glands in three species of Geophis (G. brachycephalus, G. nasalis and G. semidoliatus), all earthworm feeders. Their infralabial glands are constituted of two distinct parts: an anterolateral portion composed of mucous and seromucous cells that stretches from the tip of the dentary to the corner of the mouth, and a tubular posteromedial portion that is exclusively seromucous. The anterolateral portion receives fibers of the levator anguli oris muscle that attaches on its posterodorsal extremity while the posteromedial portion extends posteriorly to the corner of the mouth where it receives fibers of the adductor mandibulae externus medialis muscle. Furthermore, the posteromedial portion of the infralabial gland is constituted by large acini filled with secretion that is periodic acid-Schiff positive. These acini release their secretion directly into a large lumen located in the middle of the glandular portion. In the three species examined, the supralabial glands show a traditional configuration, being constituted of mucous and seromucous cells and retaining an enlarged part in its caudal region that resembles a Duvernoy's gland. The presence in Geophis of an expanded lumen in part of the infralabial gland that is compressed by an adjacent muscle suggests a more specialized role for the secretion produced by these glands that may not be related to envenomation but rather to prey transport and mucus control., (Copyright © 2013 Wiley Periodicals, Inc.)

Esophageal submucosal glands (esophageal glands proper) were studied in 19 individuals of elderly and senile age (without subdivision according to gender), as well as in persons of I period of mature age (6 to 7 cases in each group). It was shown that the glandular acini contained thin, elongated cells and cuboidal cells between the mucocytes surrounded by the myoepithelial cells. Around the acini, the myofibroblasts were found. The number of fibroblasts and lymphocytes in glandular stroma increased with age. The number of plasma cells was increased with age in the stroma of the glands of the upper part of the esophagus. Small excretory ducts were arranged in groups, often surrounded by the clusters of lymphoid cells. The number of lymphoid cells and fibroblasts around the large excretory ducts was found to increase with age.

The skin is the first line of defense against dehydration and external environmental aggressions. It constantly renews itself throughout adult life mainly due to the activity of tissue-specific stem cells. In this review, we discuss fundamental characteristics of different stem cell populations within the skin and how they are able to contribute to normal skin homeostasis. We also examine the most recent results regarding the cell-intrinsic and -extrinsic components of the stem cell niche within the adult skin epithelium. Finally, we address the recent efforts to understand how abnormal regulation of stem cell activity contributes to the initiation and progression of skin-associated cancers., (© 2014 Elsevier Inc. All rights reserved.)

Airway serous secretion is essential for the maintenance of mucociliary transport in airway mucosa, which is responsible for the upregulation of mucosal immunity. Although there are many articles concerning the importance of Toll-like receptors (TLRs) in airway immune systems, the direct relationship between TLRs and airway serous secretion has not been well investigated. Here, we focused on whether TLR5 ligand flagellin, which is one of the components of Pseudomonas aeruginosa, is involved in the upregulation of airway serous secretion. Freshly isolated swine tracheal submucosal gland cells were prepared, and the standard patch-clamp technique was applied for measurements of the whole cell ionic responses of these cells. Flagellin showed potentiating effects on these oscillatory currents induced by physiologically relevant low doses of acetylcholine (ACh) in a dose-dependent manner. These potentiating effects were TLR5 dependent but TLR4 independent. Both nitric oxide (NO) synthase inhibitors and cGMP-dependent protein kinase (cGK) inhibitors abolished these flagellin-induced potentiating effects. Furthermore, TLR5 was abundantly expressed on tracheal submucosal glands. Flagellin/TLR5 signaling further accelerated the intracellular NO synthesis induced by ACh. These findings suggest that TLR5 takes part in the airway mucosal defense systems as a unique endogenous potentiator of airway serous secretions and that NO/cGMP/cGK signaling is involved in this rapid potentiation by TLR5 signaling.

Spider silk is made of unique proteins-spidroins-secreted and stored as a protein solution (dope) in specialized glands. The major ampullate gland, source of the dragline silk, is composed of a tail, a sac and an elongated duct. For this gland, several different types of epithelial cells and granules have been described, but it is largely unknown how they correlate with spidroin production. It is also not settled what parts of the large spidroins end up in the final silk, and it has been suggested that the N-terminal domain (NT) is lacking. Here we show that NT is present in the dope and throughout dragline silk fibers, including the skin layer, and that the major ampullate tail and sac consist of three different and sharply demarcated zones (A-C), each with a distinct epithelial cell type. Finally, we show that spidroins are produced in the A and B zone epithelia, while the C zone granules lack spidroins.

Metazoans require epithelial and endothelial tubes to transport liquids and gasses throughout their bodies. Although biological tubes may look relatively similar at first glance, there are multiple and distinct mechanisms by which tubes form and even more regulatory events driving the cell shape changes that produce tubes of specific dimensions. An overview of the current understanding of the molecular processes and physical forces involved in tubulogenesis is presented in this review and the accompanying poster.

This study was designed to elucidate the presence of apoptosis and the localization of apoptosis-related Bax and survivin proteins and proliferating cell nuclear antigen (PCNA) within the chicken uropygial gland, a specialized holocrine secretory gland. In day-old chicks, survivin and Bax immunoreactivities were observed in the cell cytoplasm of the germinative and secretory layers of the luminal epithelium and tubules. During this period, the TUNEL reaction, an indication of apoptosis, was only sporadically positive in the tubules. From the 7th day to the 150th day of posthatching, survivin was detected in the cytoplasm of cells in the germinative layer and in the nuclei of some cells in the secretory layers of the gland. The germinative layer cells showed weak homogeneous cytoplasmic staining for Bax, whereas the cells of the secretory and intermediate layers of luminal epithelium and tubules exhibited granular cytoplasmic staining. After day 7, TUNEL-positive cells were observed in the secretory and degenerative layers of the luminal epithelium and central tubules. After day 12, some TUNEL-positive cells were also seen in the peripheral tubules. At all posthatch ages, the cytoplasm and nucleus of the germinative layers of luminal epithelium and tubules reacted with PCNA, whereas only a small number of cell nuclei in the secretory layers were immunopositive. These results support the theory that specific PCNA/Bax/survivin expression patterns could reflect particular cell differentiation states in the uropygial gland and that holocrine secretion in the gland is realized mainly by way of apoptosis., (Copyright © 2012 Wiley Periodicals, Inc.)

Airway submucosal glands are important sites of cystic fibrosis transmembrane conductance regulator (CFTR) chloride (Cl(-)) channel expression and fluid secretion in the airway. Whereas both mouse and human submucosal glands and their serous acinar cells express CFTR, human glands and serous cells secrete much more robustly than mouse cells/glands in response to cAMP-generating agonists such as forskolin and vasoactive intestinal peptide. In this study, we examined mouse and human serous acinar cells to explain this difference and reveal further insights into the mechanisms of serous cell secretion. We found that mouse serous cells possess a robust cAMP-activated CFTR-dependent Cl(-) permeability, but they lack cAMP-activated calcium (Ca(2+)) signaling observed in human cells. Similar to human cells, basal K(+) conductance is extremely small in mouse acinar cells. Lack of cAMP-activated Ca(2+) signaling in mouse cells results in the absence of K(+) conductances required for secretion. However, cAMP activates CFTR-dependent fluid secretion during low-level cholinergic stimulation that fails to activate secretion on its own. Robust CFTR-dependent fluid secretion was also observed when cAMP stimulation was combined with direct pharmacological activation of epithelial K(+) channels with 1-ethyl-2-benzimidazolinone (EBIO). Our data suggest that mouse serous cells lack cAMP-mediated Ca(2+) signaling to activate basolateral membrane K(+) conductance, resulting in weak cAMP-driven serous cell fluid secretion, providing the likely explanation for reduced cAMP-driven secretion observed in mouse compared with human glands.

The large airways are directly in contact with the environment and therefore susceptible to injury from toxins and infectious agents that we breath in. The large airways therefore require an efficient repair mechanism to protect our bodies. This repair process occurs from stem cells in the airways and isolating these stem cells from the airways is important for understanding the mechanisms of repair and regeneration. It is also important for understanding abnormal repair that can lead to airway diseases. The goal of this method is to isolate a novel stem cell population from the mouse tracheal submucosal gland ducts and to place these cells in in vitro and in vivo model systems to identify the mechanisms of repair and regeneration of the submucosal glands. This production shows methods that can be used to isolate and assay the duct and basal stem cells from the large airways.This will allow us to study diseases of the airway, such as cystic fibrosis, asthma and chronic obstructive pulmonary disease. Currently, there are no methods for isolation of submucosal gland duct cells and there are no in vivo models to study the regeneration of submucosal glands.

The poll glands are subcutaneous exocrine glands located on the back of the neck behind the ears in male camels. The function of poll glands is not well known, though they are thought to play a role during the rutting season. The presence, location and degree of immunolocalization of microfilaments and intermediate filament systems: actin and cytokeratins (Cks) and also S100 protein were studied in the poll glands in sexually mature one-humped camels during the rutting season. These proteins were variably expressed between the epithelia, perialveolar, interalveolar tissue and the periductal tissue. Strong α-smooth muscle actin (α-SMA) immunoreactivity (IR) was displayed by the perialveolar myoepithelial cells, periductal and vascular smooth muscle cells (SMCs), but not in the epithelial cells. Cytokeratin (Ck)-IR was strong in the epithelial lining of the secretory alveoli and excretory ducts, however, the apical blebs of the secretory cells were almost negative. Weak to moderate Ck-IR was observed in the perialveolar myoepithelial cells, but not in the interalveolar tissue or endothelial cells. S100 protein was expressed variably in the epithelial lining of the secretory alveoli. S100-IR was more obvious in the supranuclear region and the apical blebs. Variable reaction was observed in the perialveolar myoepithelial cells, periductal and interductal tissue and endothelial cells., (Copyright © 2011 Elsevier GmbH. All rights reserved.)

Hair evolution contributed to the biological success of mammals. Hair origin from synapsid scales is speculative and requires extensive modifications of the morphogenetic process transforming lens-shaped dermis of scales into small dermal papillae in hair. Hair evolution from glands is hypothetical but is supported from studies on the signaling control of hair vs. glandular morphogenesis. Based on immunocytochemical and comparative studies, it is hypothesized that the onion-like organization of hair derived from glandular pegs which central part produced lipids and some keratin. In a following stage, involucrin, trichohyalin, and keratins were produced in the central cells of the gland and formed a solid medulla surrounded by keratinocytes of the inner root sheath. The origin of this protohair was possibly related to increased concentration of beta-catenin and other signaling molecules in epithelial cells following the evolution of a dermal papilla. The latter activated the keratogenic genes, already utilized in cells of the claws, in concentric layers of cells of the glandular peg. Lipidogenic genes were depressed. As new genes evolved in the genome of synapsids, new circular layers of keratinocytes containing specialized hard keratins and keratin-associated proteins were formed around medullary cells. The new keratinocytes probably originated the cortex separating medulla from the external cells that became the inner root sheath. The hypothesis indicates that in a following stage, the medulla was obliterated or replaced by cortical cells while the external part of the cortex formed a cuticular surface due to the different growth rate with inner root sheath cells., (© 2012 WILEY PERIODICALS, INC.)

Objective: To study the phenotypic characteristics of and the balance between systemic IL-7 receptor (IL-7R)α+ and IL-7Rα- Tregs in primary SS (pSS) patients as compared with control subjects and to assess the functional consequences this has for (IL-7-induced) T-cell activation., Methods: The functional properties of IL-7Rα+ and IL-7Rα- (CD25+) CD4 T cells from pSS patients were tested in vitro. Expression of CD25 and FoxP3 by IL-7Rα+ and IL-7Rα- CD4 T cells from pSS patients and healthy controls (HCs) were assessed. Also, the net ex vivo T-cell cytokine production and the capacity of IL-7 to activate total CD4 T cells from pSS patients compared with HCs in vitro was tested., Results: IL-7Rα+ T cells from pSS patients strongly proliferated and their numbers were slightly reduced compared with HCs. This reduced number was caused by an increase in both anergic and suppressive IL-7Rα- CD25+ T cells expressing high levels of FoxP3, but also by increases in IL-7Rα- CD25- CD4 T cells that only moderately expressed FoxP3. This altered balance in IL-7Rα+ and IL-7Rα- CD4 T cells was accompanied by unchanged ex vivo Th1, Th2 and Th17 cytokine production of total CD4 T cells. Furthermore, the increased numbers of IL-7Rα- CD25+ T cells did not prevent specific IL-7-induced Th1 and Th17 cytokine production by IL-7Rα+ T cells., Conclusion: IL-7Rα+ cells are highly proliferating cells that respond strongly to IL-7 despite an increased number of IL-7Rα- T cells that express FoxP3 and CD25. The recent finding that IL-7 and IL-7Rα+ T cells were both found to be increased in exocrine glands of pSS patients indicates that IL-7 could contribute to glandular inflammation by activation of IL-7Rα+ responder T cells despite the increased numbers of Tregs.

Background: Secretions within the adult female reproductive tract mediate sperm survival, storage, activation, and selection. Drosophila female reproductive gland secretory cells reside within the adult spermathecae and parovaria, but their development remains poorly characterized., Results: With cell-lineage tracing, we found that precursor cells downregulate lozenge and divide stereotypically to generate three-cell secretory units during pupal development. The NR5A-class nuclear hormone receptor Hr39 is essential for precursor cell division and secretory unit formation. Moreover, ectopic Hr39 in multiple tissues generates reproductive gland-like primordia. Rarely, in male genital discs these primordia can develop into sperm-filled testicular spermathecae., Conclusion: Drosophila spermathecae provide a powerful model for studying gland development. Hr39 functions as a master regulator of a program that may have been conserved throughout animal evolution for the production of female reproductive glands and other secretory tissues., (Copyright © 2012 Elsevier Ltd. All rights reserved.)

Malfunction of airway submucosal glands contributes to the pathology of cystic fibrosis (CF), and cell cultures of CF human airway glands show defects in Cl(-) and water transport. Recently, a transgenic pig model of CF (the CF pig) has been developed. Accordingly, we have developed cell cultures of pig airway gland epithelium for use in investigating alterations in gland function in CF. Our cultures form tight junctions (as evidenced by high transepithelial electrical resistance) and show high levels of active anion secretion (measured as amiloride-insensitive short-circuit current). In agreement with recent results on human airway glands, neurohumoral agents that elevate intracellular Ca(2+) potently stimulated anion secretion, while elevation of cAMP was comparatively ineffective. Our cultures express lactoferrin and lysozyme (serous gland cell markers) and MUC5B (the main mucin of airway glands). They are, therefore, potentially useful in determining if CF-related alterations in anion transport result in altered secretion of serous cell antimicrobial agents or mucus.

The venom gland apparatus of Bothrops jararaca is composed of four distinct parts: main venom gland, primary duct, accessory gland and secondary duct. Despite the numerous studies concerning morphology and venom production and secretion in the main venom gland, there are few studies about the accessory gland and its secretion. We characterized the accessory gland of B. jararaca snake and determined the secretion cycle by morphological analysis using light and transmission electron microscopy. Our data showed that the accessory gland of B. jararaca has a simple secretory epithelium with at least six types of cells in the anterior region: two types of secretory cells, mitochondria-rich cells without secretory vesicles, horizontal cells, dark cells and basal cells, and in the posterior region a simple epithelium with two types of cells: seromucous cells and horizontal cells. Furthermore, the mucous secretory cells of the accessory gland show a delayed and massive exocytosis that occurs four days after the extraction of venom. Morphological analysis at different steps after venom extraction showed that the accessory gland has a long cycle of production and secretion, which is not synchronous with the main venom gland secretory cycle., (Copyright © 2011 Elsevier Ltd. All rights reserved.)

The subfamily Syntermitinae comprises 14 genera of termites that are exclusively neotropical. The present study reports morphological data about mandibulate nasute soldiers from termite species belonging to three different genera within this subfamily. We describe tergal glands that were present under all tergites of soldiers of the following species: Cornitermes cumulans, Procornitermes araujoi, Syntermes nanus, and Syntermes wheeleri. The tergal glands were composed of class 2 and class 3 cells. Class 2 cells never reached the cuticle and were located below a flat layer of epidermal cells. Class 3 cells, composed of secretory cells and canal cells, were sporadic, whereas class 2 secretory cells were abundant. Secretory cells of class 3 were narrow and their cytoplasms were filled with several clear, oval-shaped vesicles with limiting membranes. The ultrastructure of class 2 cells showed well-developed smooth endoplasmic reticulum, Golgi apparatus, elongated mitochondria, several electron-lucent vesicles, and electron-dense granules that contain paracrystalline structures in S. nanus. Scanning electron micrographs displayed pores, campaniform sensilla and hairs in the outer cuticle of the soldier tergites. We hypothesize that soldier tergal glands may be involved in the production of defensive compounds, which occur in similar glands of certain cockroaches, or of primer pheromones, that might act in the regulation of soldier differentiation in the termite colony. To date, tergal glands have only been described in termite imagoes, and their occurrence in these soldiers of basal Syntermitinae implies a specific role in this caste that is still speculative and needs to be clarified., (Copyright © 2011 Elsevier Ltd. All rights reserved.)

The Drosophila male accessory gland has functions similar to those of the mammalian prostate gland and the seminal vesicle, and secretes accessory gland proteins into the seminal fluid. Each of the two lobes of the accessory gland is composed of two types of binucleate cell: about 1,000 main cells and 40 secondary cells. A well-known accessory gland protein, sex peptide, is secreted from the main cells and induces female postmating response to increase progeny production, whereas little is known about physiological significance of the secondary cells. The homeodomain transcriptional repressor Defective proventriculus (Dve) is strongly expressed in adult secondary cells, and its mutation resulted in loss of secondary cells, mononucleation of main cells, and reduced size of the accessory gland. dve mutant males had low fecundity despite the presence of sex peptide, and failed to induce the female postmating responses of increased egg laying and reduced sexual receptivity. RNAi-mediated dve knockdown males also had low fecundity with normally binucleate main cells. We provide the first evidence that secondary cells are crucial for male fecundity, and also that Dve activity is required for survival of the secondary cells. These findings provide new insights into a mechanism of fertility/fecundity.

We found that the androgenic gland (AG) of Macrobrachium rosenbergii possesses three cell types. Type I cells are small polygonal shaped-cells (13.4 μm in diameter), stain strongly with hematoxylin-eosin (H&E), have abundant multilayered rough endoplasmic reticulum (rER), and nuclei containing mostly heterochromatin. Type II cells are slightly larger (18.6 μm in diameter), stain lightly with H&E, have rER with dilated cisternae, and nuclei containing mostly euchromatin. Type III cells (previously undescribed) are similar in size and shape to type I cells, but the cytoplasm is unstained and they have a high amount of smooth endoplasmic reticulum (sER) and mitochondria with tubular cristae. Bilateral eyestalk-ablation resulted in AG hypertrophy with a proliferation and predominance of type I cells as determined by bromodeoxyuridine (BrdU) assays. Expression of insulin-like androgenic gland hormone (Mr-IAG), determined by immunohistochemistry, was weak in type I cells, strong in type II cells of both the intact and eyestalk-ablated, and negative in type III cells. It was also detected in spermatogonia, nurse cells, and epithelium lining of the spermatic duct. The function of Mr-IAG in these tissues is yet to be elucidated but the distribution implies a strong role in male reproduction., (Copyright © 2011 Elsevier Ltd. All rights reserved.)

During pupal metamorphosis, the anterior silk glands (ASGs) of the silkworm Bombyx mori degenerate through programmed cell death (PCD), which is triggered by 20-hydroxyecdysone (20E). 20E triggers the PCD of the ASGs of day 7 fifth instar (V7) larvae but not that of V5 larvae. When V7 ASGs were cocultured with V5 ASGs in the presence of 20E, neither culture of ASGs underwent PCD. The 20E-induced PCD of V7 ASGs was also inhibited when they were incubated in conditioned medium that was prepared by incubating V5 ASGs for 48 h, an indication that V5 ASGs released an inhibitor of 20E-induced PCD during incubation. The inhibitor was purified from conditioned medium and identified as glucose oxidase (GOD). GOD catalyzes the oxidation of glucose to gluconolactone, and generates hydrogen peroxide as a byproduct. We found that hydrogen peroxide is the molecule that directly inhibits the action of 20E and may act to protect the ASGs from early execution of PCD during the feeding stage. GOD was localized in the inner cavity of the gland, and was discharged to the outside of the ASGs with the silk thread at the onset of spinning. Thus, the spinning behavior, occurring at the beginning of the prepupal period, plays an important role in controlling the time at which ASGs undergo PCD in response to 20E., (© 2011 The Authors Journal compilation © 2011 FEBS.)