Giant secretory granules in the ducts of the parotid and submandibular glands of the slow loris

The parotid and submandibular glands of a slow loris, a rare Southeast Asian primate, were obtained after the head had been perfused by fixative for a study of the brain. These tissues were processed by conventional means for electron microscopy. Glands also were obtained at autopsy from 2 other lorises, fixed by immersion in formalin, and subjected to a battery of tests for glycoconjugates. In the parotid gland, a short segment of the proximal striated duct lacks both basal striations and any sign of secretory activity. The major portion of the striated duct consists of tall cells that contain a spectrum of secretory granules, some larger than the nuclei (many granules are > 9 mum in diameter). These granules, which are delimited by a single membrane, are capable of chain exocytosis. Many of the giant granules have bundles of cytofilaments (4.5-6.5 nm) in apparent association with their surface. Occasional cells contain numerous small granules. Duct cells with or without granules lack basal striations. The granules contain neutral glycoconjugates but no acidic glycoconjugates. Some, but not all, interlobular excretory ducts also have secretory granules that run the gamut from tiny to giant. Exactly the same situation occurs in the submandibular gland. Unlike other primates, which may have duct cells that contain only a few tiny granules in their apices, the cells in both the striated and excretory ducts in the slow loris appear to be specialized for secretion rather than for transport. The biofunction of the giant granules is unknown.     

Ultrastructure of secretion in the atrial gland of a mollusc (Aplysia)

Extracts of the atrial gland of the sea hare Aplysia californiea (Mollusca) induce egg laying when injected into mature individuals. Since egg laying is controlled endogenously by a peptide secreted by neuroendocrine cells in the central nervous system, the relationship between the atrial gland and these central neurons has become an issue of interest. With the particular objective of examining secretory structures we undertook an ultrastructural study of the atrial gland and adjacent tissues. This study revealed that the atrial gland epithelium is composed of two major cell types: ‘goblet-like’ exocrine cells containing large electron-dense granules, and ciliated ‘capping cells’. A non-secretory, and possibly post-secretory, cell containing electron-lucent granules was noted. A region of the large hermaphroditic duct contiguous to the atrial gland, known as the red hemiduct, also displayed capping cells and secretory cells with large granules. The content of these granules is organized into crista-like condensations. The cell also contains iron-rich pigment inclusions.     

COMPARISON OF SPONTANEOUS LOSS OF CATECHOLAMINES AND ATP IN VITRO FROM ISOLATED BOVINE ADRENOMEDULLARY, VESICULAR GLAND, VAS DEFERENS AND SPLENIC NERVE GRANULES

The molar ratio catecholamines/ATP in the high speed sediment from homogenates of bovine adrenal medulla, vesicular gland, vas deferens and splenic nerve was relatively close to the‘equivalence ratio’of 4/1. On incubation in vitro the loss of amines and ATP from the medullary granules was slow and largely parallel. Thus the original amine/ATP ratio was maintained. The amine loss from the nerve granules occurred at a very high, and from the vesicular gland and vas deferens granules at an intermediate, rate. On the other hand, the decrease in ATP in these preparations was quite slow, leading to a marked change in the original amine/ATP ratio. These findings are regarded as further evidence of functional differences between granules derived from chromaffin cells and from sympathetic nerve tissue, and even between nerve granules from‘long’and 'short’noradrenergic neurons. The possible implications of these in vitro differences in amine and ATP release are discussed in relation to the mechanisms of amine release in vivo.     

Histology of vermiform appendix-like organ in slow loris.

The vermiform appendix-like organ (VALO) of the slow loris was investigated for its histology and immunohistochemical characteristics. The VALO has a much thinner wall with flat folded mucosa and shallower crypts than the cecal mucosa, while cellular components and population of the mucosa were similar to those of the cecum. No coalescent lymph nodules were seen in the submucosa. Immunohistochemically 5-HT-positive cells in the crypts and CD3- and CD8-positive lymphocytes in the lymph nodules were shown in the VALO as well as in the cecum. These findings suggest that the VALO is a low-differentiated vermiform appendix of the slow loris.     

The subependyma of the primate, slow loris (Nycticebus coucang coucang)

The subependymal plate of the primate slow loris (Nycticebus coucang coucang) has been studied by electron microscopy. It is composed of a mixed population of several cell types in which the subependymal cells preponderate. Free subependymal cells are found in the ‘border area’ near the corpus callosum or the neuropile of the caudate nucleus. In common with the subependymal cells they show a scanty cytoplasm containing mostly free ribosomes. Typical neuroglial cells namely, microglia, astrocytes and oligodendrocytes are also identified in this region. Among the various cell types mentioned there are present also a few occasional cells which have features bearing a resemblance to the subependymal cell on the one hand and to the microglia on the other. The morphological evidence suggests that in parallel with the macroglia the microglia could be derived by stepwise transformation of the subependymal cells.     

Coexistence between Javan Slow Lorises (<Emphasis Type="Italic">Nycticebus javanicus</Emphasis>) and Humans in a Dynamic Agroforestry Landscape in West Java,Indonesia

In a world increasingly dominated by human demand for agricultural products, we need to understand wildlife’s ability to survive in agricultural environments. We studied the interaction between humans and Javan slow lorises (Nycticebus javanicus) in Cipaganti, Java, Indonesia. After its introduction in 2013, chayote (Sechium edule), a gourd grown on bamboo lattice frames, became an important cash crop. To evaluate people’s use of this crop and to measure the effect of this increase on slow loris behavior, home ranges, and sleep sites, we conducted interviews with local farmers and analysed the above variables in relation to chayote expansion between 2011 and 2015. Interviews with farmers in 2011, 2013, and 2015 confirm the importance of chayote and of bamboo and slow lorises in their agricultural practices. In 2015 chayote frames covered 12% of land in Cipaganti, occupying 4% of slow loris home ranges, which marginally yet insignificantly increased in size with the increase in chayote. Slow lorises are arboreal and the bamboo frames increased connectivity within their ranges. Of the sleep sites we monitored from 2013 to 2016, 24 had disappeared, and 201 continued to be used by the slow lorises and processed by local people. The fast growth rate of bamboo, and the recognition of the value of bamboo by farmers, allow persistence of slow loris sleep sites. Overall introduction of chayote did not result in conflict between farmers and slow lorises, and once constructed the chayote bamboo frames proved to be beneficial for slow lorises.     

Ultrastructural changes of the teleostean hatching gland cell during natural and electrically induced precocious secretion.

Ultrastructural changes of the hatching gland during electrically induced precocious secretion were compared with those during natural secretion in the medaka, Oryzias latipes. The gland cells are covered by a layer of epithelial cells, which adjoin one another just on the apical center of each gland cell. When the natural as well as the precocious secretion occurred, each gland cell was swollen upward and rounded, and separation of the epithelial joints occurred, giving rise to an exposure of the apical portion of the gland cells. There were marked differences between these two kinds of secretion process in the behavior of the secretory granules prior to secretion and in the mode of discharge of the secretory substances. The changes which occurred during both types of secretion and which, therefore, seemed to be essential to the secretory processes of this gland cell were the swelling up of the gland cells in the initiation of secretion and the reduction of the electron density of the zymogen granules. These secretion-associated ultrastructural changes are discussed in view of the difference in the maturation of the gland cells.     

Cadmium stress stimulates tissue turnover in Helix pomatia: increasing cell proliferation from metal tolerance to exhaustion in molluscan midgut gland

In terrestrial pulmonate snails, cadmium (Cd) uptake leads to the induction of a Cd-specific metallothionein isoform (Cd-MT) that protects against adverse interactions of this toxic metal ion. Increasing concentrations of Cd cause increased individual mortality possibly linked to pathological alterations in the snail midgut gland. Histological, immuno-histochemical, and electron-microscopic methods in combination with tissue metal analyses and quantification of MT induction parameters were applied to the midgut gland of Cd-exposed Roman snails (Helix pomatia). Conspicuous concentration-dependent alterations occurred in this organ, including the metal-induced increase of Cd-MT concentration and manifestation of Cd-MT mRNA precipitations in all midgut gland cell types. The most evident alteration was an increase of cellular turnover reflected by enhanced cell proliferation. Intensified vesiculation of endoplasmic reticulum was noted in basophilic cells and an increasing formation of lipofuscin granules in excretory cells. At the highest Cd concentrations, mitochondrial membranes were disrupted in basophilic cells, and lipofuscin granules were released from excretory cells into the midgut gland tubular system. Some of these alterations (e.g., increased cell proliferation rate, vesiculation of endoplasmic reticulum) detected at low Cd concentrations were interpreted as adaptive response processes enhancing the tolerance of exposed individuals to metal stress. Cellular alterations at higher Cd concentrations (e.g., mitochondrial structural damage) clearly represented ongoing irreversible cellular disruption. Combined evaluation of cellular biomarkers and MT saturation levels indicated that the transition from stress resistance to depletion of resistance capacity occurred above a threshold of 0.8 µmol Cd/g dry weight in the midgut gland of H. pomatia. At these Cd concentrations, Cd-MT was saturated with Cd²⁺ ions, whereas at the cellular level, structural alterations turned into pathological deterioration.     

The hormonal control of salivary gland secretion in Drosophila melanogaster: Studies in vitro

The larval salivary gland of Drosophila melanogaster synthesises a complex secretion, known as ‘glue’. which is secreted at puparium formation and then cements the puparium to its substrate. This secretion is made during the third larval instar and is stored in the gland cells as large granules. A few hours before puparium formation it is secreted into the gland's lumen by exocytosis. This process is induced by ecdysone and can be studied in vitro. Secretion is initiated about 3.5 hr after exposure of glands to ecdysone and is complete by 8 hr. The effects of varying the ecdysone concentration, of inhibitors of RNA or protein synthesis, and of withdrawing the hormone at various times after initial exposure on the process of secretion have been studied. We conclude that some event(s) occurring during the first 3 hr exposure to ecdysone is necessary to initiate secretion of the glue into the gland lumen. The possible relationship between this event(s) and the ecdysone induced changes in gene activity (puffs) which occur in the salivary glands at the same time is discussed.     

Hiding in the dark: Local ecological knowledge about slow loris in Sarawak sheds light on relationships between human populations and wild animals

Local ecological knowledge (LEK) increases understanding of certain species and the threats they face, especially little-studied taxa for which data on distribution and conservation are often lacking. We conducted 111 semi-structured interviews in Sarawak, Malaysia, to collect local knowledge about the behavior and distribution of the Philippine slow loris (Nycticebus menagensis) from two ethnic groups, the Iban and the Penan. Our study revealed that male Penan respondents, generally hunters, who frequently go into the forest were better at identifying animals from pictures. Overall, the Penan have a more detailed knowledge of slow loris behaviors, habitat, and distribution than the Iban. The two ethnic groups have different attitudes towards slow loris as the Penan hunt, eat, or keep them as pets while the Iban consider them sacred and signifiers of good luck. We advocate the use of LEK for providing complementary information to scientific methods in the study of cryptic animals.     

An integumentary gland secreting a territorial marking pheromone in Atta sp.: Detailed structure and histochemistry

An abdominal pheromone-producing gland in Atta sp. was examined using light and electron microscopy techniques. The gland is composed of a bunch of juxtaposed secretory units in which the secretory ductules open on to a cribellum close to the sting base.The structure and cycles of the secreting units are described. Each includes a secretory cell with an ‘end apparatus’, ductule cells and epidermal cells. The secretory cycle of glycoproteins accumulated in the ‘end apparatus’ is discussed and a functional interpretation of the morphological components of the application system is proposed.     

Electrophysiological studies on embryonic heart cells in culture. Scorpion toxin as a tool to reveal latent fast sodium channel

Trypsin-dispersed heart cells were obtained from 11-day-old chick embryos. After culture as unstirred suspensions in dimethylsulfoxide-containing medium, spherical aggregates of cells beating spontaneously and apparently synchronously for months were obtained. Two kinds of cell were characterized by electrophysiological recordings: (1) cells with a slow rate of depolarizing phase showing tetrodotoxin-resistant action potential and blocked by D 600 (‘slow’ cells); (2) cells with high value of rising phase which was strongly decreased by tetrodotoxin and in which D 600 provoked uncoupling of excitation-contraction (‘fast’ cells).Toxin II from Androctonus australis scorpion venom increased the duration of action potential, which was ascribed to a slowing down of Na⁺ current inactivation and enhance the maximum rate of depolarization, especially in slow cells. Effects were antagonized by tetrodotoxin in both fast and slow cells. Washing experiments confirmed the results of previous studies, namely that tetrodotoxin and scorpion toxin bind to different receptors. It is concluded that slow cells with tetrodotoxin-resistant action potential contain latent fast Na⁺ channels that are revealed (activated) by toxin binding to the membrane.     

The effect of monovalent cations on calcium efflux in yeasts

The properties of the calcium efflux system in the yeast Saccharomyces cerevisiae were investigated. After growing the cells overnight in medium containing ⁴⁵Ca, the cells were transferred to medium containing glucose, Hepes buffer (pH 5.2) and monovalent cations. The presence of potassium or sodium in the medium induced efflux of calcium from the cells. The magnitude of the efflux was dependent on the concentration of these cations in the medium. The time course of calcium efflux was analyzed, and two types of exchangeable calcium pools, which turned over at different rates, were detected: ‘Fast turnover’ and ‘slow turnover’. Increase in the concentration of monovalent cations in the medium caused an increase in the fraction of cellular calcium which turned over at a fast rate, and activation of calcium efflux from the ‘slow turnover’ calcium pool. The specific changes in the parameters of calcium efflux induced by monovalent cations were different from those reported previously to be induced by divalent cations. Both processes, i.e. activation of calcium efflux by monovalent and by divalent cations, were found to be additive, indicating that they operate via different mechanisms. Experiments using the respiratory inhibitor Antimycin A, showed that stimulation of calcium efflux by monovalent cations is energy dependent. Lanthanum ions which are known to inhibit calcium influx into yeast cells, inhibitted the activation of calcium efflux by both divalent and monovalent cations. Determination of the cationic composition of the cells indicated that the stimulation of calcium efflux was accompanied by influx of potassium or sodium into the cells.     

Interactions between a wild Bornean orang-utan and a Philippine slow loris in a peat-swamp forest

All documented orang-utan–loris interactions have been from Sumatra, where lorises were opportunistically preyed upon by orang-utans. In this paper, we describe two accounts of the Bornean orang-utan (Pongo pygmaeus wurmbii) interacting with the Philippine slow loris (Nycticebus menagensis). The interactions were by two adolescent female orang-utans. No attempts to catch the loris were observed on either occasion. Neither interaction was hostile. During the second observation, which was more detailed, we considered the behaviour to be play rather than aggression or attempted predation. Based upon the lack of interest from the adult females during these rare encounters, we propose that the behaviour represents play or non-aggressive exploration rather than predation.     

The formation of glandular secretion in larval Austramphilina elongata (Amphilinidea)

The ultrastructure of three types of gland cells of embryos and free-swimming larvae of Austramphilina elongata is described. Type I gland cells contain large, more or less round electron-dense granules which are formed by numerous Golgi complexes. Type II gland cells contain thread-like, membrane-bound secretory granules with longitudinally arranged microtubules inside the granules; secretory droplets are produced by Golgi complexes and the microtubules apparently condense in the cytoplasm or in the droplets. Type III gland cells contain irregular-ovoid membrane-bound granules with coiled up microtubules which have an electron-dense core; the granules are formed by secretionderived from Golgi complexes and the microtubules aggregate around and migrate into the secretion; microtubules are at first hollow and the early secretory granules have a central electron-dense region.     

Colour and colour change in the grasshopper, Kosciuscola tristis

The males of the small grasshopper (Kosciuscola tristis), with a restricted range above 1830 m in the Australian Alps, exhibit a remarkable colour change. They are dark, almost black, when cold and change to a bright sky blue colour within minutes of exposure to warmth.Sections of cuticle fixed in the two conditions confirm that the cells underlying the cuticle contain two kinds of granules: large (diameter 1·0 μm) spherical, brown granules, and smaller (0·17 μm) less dense granules. In the blue (warm) condition the small granules are closely packed in the distal part of the cells, whereas the ‘black’ granules are found predominantly in the deeper proximal zones. Evidence is presented to suggest that the blue colour arises from Tyndall scattering of light by the suspension of small granules and is intensified by being seen against a dark background.In the black condition the black granules are found to have moved towards the surface, mingling with the smaller granules and ‘quenching’ the light scattering.The smaller granules are white in the isolated state. They consist of a mixture of uric acid and a pteridine, probably leucopterin.The epidermal cells contain numerous microtubules, which are directed towards the cell surface, that is, parallel to the direction of movement of the granules. It is possible that the microtubules are associated with the movement.     

The fine structure of the light organ of the New Zealand glow-worm Arachnocampa luminosa (Diptera: Mycetophilidae).

The swollen distal tips of the Malpighian tubules of the glow-worm Arachnocampa luminosa constitute the light organ. The ventral and lateral surfaces are covered by a tracheal ‘reflector’ and the nervous supply to the light organ comes from the ganglion in the penultimate segment. Fine nerve terminals, axons, and glial cells can be seen in close proximity to the basal surface of the cells of the light organ. The epithelial cells of the light organ are large, the cytoplasm dense, homogeneous and acidophilic. The cytoplasm gives a strong positive reaction for protein. The cytoplasm contains a high density of free ribosomes, patches of dense material, smooth endoplasmic reticulum, glycogen and scattered microtubules. Mitochondria are numerous; they are large, randomly distributed and packed with fine cristae. These cells lack the features characteristic of Malpighian tubule epithelial cells; infolding of the apical and basal cell surfaces is reduced and the cytoplasm contains few organelles. These cells do not contain secretory or photocyte granules and the grainy cell matrix is thought to be the luciferin substrate. Oxygen is supplied via the tracheal layer (which may have secondary reflecting properties) and light production controlled by neurosecretory excitation either directly via synapses, or by hormones. There are no other reports of Malpighian tubules of insects producing light and the fine structure of these cells is distinct. Thus, the swollen distal tips of the Malpighian tubules of the glow-worm undoubtedly constitute a unique luminescent organ.     

Fine Structure of the Esophagus of Males of Sarisodera hydrophila (Heteroderoidea)

The fine structure of the esophagus, including procorpus, metacorpus, isthmus, gland lobe, and esophago-intestinal junction, is examined in males of Sarisodera hydrophila. A cuticle-lined lumen extends most of the length of the esophagus, broadens to form a pump chamber in the metacorpus, and posteriorly is continuous with junctional complexes among four esophago-intestinal cells. These four cells are partially enveloped by the gland lobe which basically consists of three gland cells, one dorsal and two subventral. Each gland cell has an anterior process which opens into the lumen of the esophagus through a cuticle-lined duct. The dorsal gland joins the lumen in the anterior portion of the procorpus, whereas ducts of the subventral glands terminate at the base of the metacorpus pump chamber. The subventral glands are predominant in the posterior portion of the gland lobe and are partially ensheathed by a narrow portion of the dorsal gland which extends to within 5 μm of the posterior terminus of the gland lobe. Contents of the dorsal gland include primarily electron dense granules, although rough endoplasmic reticulum (RER) is predominant posteriorly. Secretory granules within the subventral glands vary in morphology and are evenly distributed throughout the two ceils among other organelles, including RER and a large Golgi apparatus. Innervation of the esophagus includes nerve processes which originate from several perikaryons (cell bodies) located in the anterior portion of the gland lobe. The esophagus of males of S. hydrophila is compared with that of other Heteroderoidea, Heterodera glycines and Meloidogyne incognita.     

Neuroglia in the corpus callosum of the primate, slow loris (Nycticebus coucang coucang)

The corpus callosum of adult slow loris consists of a mixed population of several cell types, i.e. free subependymal cells, oligodendrocytes, astrocytes and microglia. The free subependymal cell is rather small and slender with a somewhat patchy nucleus. It shows scanty cytoplasm with free ribosomes. Oligodendrocytes vary both in nuclear and cytoplasmic densities and can be divided into three classes: light, medium dense and dark types. Their cytoplasm contains microtubules, rough endoplasmic reticulum and Golgi saccules. Astrocytes are pale cells with large amount of filaments in their cytoplasm. Microglia are small cells with granulated nuclei. The cells often show large cytoplasmic protrusions containing the usual cell organelles and lipofuscin bodies in their cytoplasm. Lastly, cells with typical features of neurons are occasionally encountered among the white matter.