The sensory basis of trail following in some lepidopterous larvae: contact chemoreception

ABSTRACT. . Caterpillars of the genus Malacosoma follow trails of the chemical 5-beta-cholestane-3,24-dione, but nothing is known of how they perceive this compound, or more generally about the sensory basis of trail following in caterpillars. By selective ablations of chemosensory organs we show that, in Malacosoma , the trail chemical is perceived by the maxillary palpi. In another lepidopteran species, Yponomeuta cagnagellus , the palpi are needed to discriminate their own trails from a trail of Malacosoma. Malacosoma larvae also lose their specificity for conspecific trails when their palpi are ablated. Volatile cues evidently do not play a role in trail-following behaviour, since neither Malacosoma nor Yponomeuta can orient on a trail covered with fine nylon mesh. These data indicate that for Malacosoma , and probably also for Yponomeuta , contact chemoreception mediated by the maxillary palpi is the primary mode of pheromone perception. The evolution of receptor sensitivity to trail chemicals in caterpillars is discussed.     

The Pyrexia transient receptor potential channel mediates circadian clock synchronization to low temperature cycles in Drosophila melanogaster

Circadian clocks are endogenous approximately 24 h oscillators that temporally regulate many physiological and behavioural processes. In order to be beneficial for the organism, these clocks must be synchronized with the environmental cycles on a daily basis. Both light : dark and the concomitant daily temperature cycles (TCs) function as Zeitgeber (‘time giver’) and efficiently entrain circadian clocks. The temperature receptors mediating this synchronization have not been identified. Transient receptor potential (TRP) channels function as thermo-receptors in animals, and here we show that the Pyrexia (Pyx) TRP channel mediates temperature synchronization in Drosophila melanogaster. Pyx is expressed in peripheral sensory organs (chordotonal organs), which previously have been implicated in temperature synchronization. Flies deficient for Pyx function fail to synchronize their behaviour to TCs in the lower range (16–20°C), and this deficit can be partially rescued by introducing a wild-type copy of the pyx gene. Synchronization to higher TCs is not affected, demonstrating a specific role for Pyx at lower temperatures. In addition, pyx mutants speed up their clock after being exposed to TCs. Our results identify the first TRP channel involved in temperature synchronization of circadian clocks.     

Moths use multimodal sensory information to adopt adaptive resting orientations

Camouflage conceals animals from predators and depends on the interplay between the morphology and behaviour of animals. Behavioural elements of animals, such as the choice of a resting spot or posture, are important for effective camouflage, as well as the animals’ cryptic appearance. To date, the type of sensory input that mediates resting site choice remains poorly understood. Previously, we showed that bark‐like moths perceive and rely on bark structure to seek out cryptic resting positions and body orientations on tree trunks. In the present study, we investigated the sensory organs through which moths perceive the structure of bark when positioning their bodies in adaptive resting orientations. We amputated (or blocked) each one of the hypothetical sensory organs in moths (antennae, forelegs, wings, and eyes) and tested whether they were still able to perceive bark structure properly and adopt adaptive resting orientations. We found that visual information or stimulation is crucial for adaptively orienting their bodies when resting and tactile information from wings may play an additional role. The present study reveals multimodal information use by moths to achieve visual camouflage and highlights the sensory mechanism that is responsible for the adaptive behaviour of cryptic insects. © 2014 The Linnean Society of London, Biological Journal of the Linnean Society, 2014, 111 , 900–904.     

Collar cells in planula and adult tentacle ectoderm of the solitary coral Balanophyllia regia (anthozoa eupsammiidae)

Summary The planula larva of the solitary coral Balanophyllia regia has an ectoderm of flagellate, diplosomal collar cells. The collar of these cells is composed of a ring of microvilli linked with mucus strands. Four types of flagellate gland cells, three types of nematocyst and spirocysts are present in the planula ectoderm. The function of these ectoderm cells is discussed. The mesogloeal muscular and packing tissues of the planula are briefly described. The tentacle of the adult coral, examined for comparison, has an ectoderm of flattened flagellate cells with a shallow collar. Collar cells similar to those of the planula are occasionally found on the tentacle and their function is not known. Independent sensory cells built on a modified collar cell plan with collar of thickened microvilli are common in the tentacle. These are quite separate from the three kinds of tentacular nematocyte. Distended glandular areas occur in the tentacle ectoderm. The flagellate tentacle gastrodermis, muscle and mesogloeal region are briefly described. The evolutionary significance of collar cell ectoderm in a planula is discussed and the occurrence of collar cells throughout the animal kingdom, reviewed.I am most grateful to Paul Tranter of the Plymouth Laboratory for providing material and to Gareth Morgan for assistance with electron microscopy.     

Chemical composition of volatiles emitted by Ziziphus jujuba during different growth stages

The volatiles emitted in vivo by different organs (leaf, bud flower, flower, green and red fruits) of Ziziphus jujuba were analysed using HS-SPME-GC/MS. A total of 144 compounds were identified corresponding to 94.6–99.4% of the whole aroma profile of jujube samples. The main constituents detected were (E, E)-α-farnesene, (E)-β-ocimene, perillene, γ-terpinene, cis-sabinene-hydrate, trans-sabinene-hydrate and 4-terpineol. The SPME analyses of the collected samples showed different patterns of emission and can contribute to understand their ecological interactions and fruit production management.     

红豆杉营养器官的解剖学研究

通过对红豆杉营养器官的解剖学研究,阐明其根、茎、叶的结构特征,为红豆杉的开发利用研究提供了解剖学依据。研究结果表明红豆杉营养器官具有以下特征：（1）根、茎、叶中均无树脂道;（2）根、茎皮层中均有含单宁类物质的细胞分布;（3）根、茎中均有石细胞分布,（4）叶气孔器为双环型,略内陷;（5）根为二原型,（6）幼根的内皮层具凯氏带加厚,中柱鞘细胞富含单宁类物质;（7）根的次生维管组织中射线发达。     

The evolution of electroreception and bioelectrogenesis in teleost fish: a phylogenetic perspective

According to current phylogenetic theory, both electroreceptors and electric organs evolved multiple times throughout the evolution of teleosts. Two basic types of electroreceptors have been described: ampullary and tuberous electroreceptors. Ampullary‐type electroreceptors appeared once in the common ancestor of the Siluriformes+Gymnotiformes (within the superorder Ostariophysi), and on two other occasions within the superorder Osteoglossomorpha: in the African Mormyriformes and in the African Notopteriformes. Tuberous receptors are assumed to have evolved three times; all within groups that already possessed ampullary receptors. With the exception of a single catfish species, for which studies are still lacking, all fish with tuberous electroreceptors also have an electric organ. Tuberous electroreceptors are found in the two unrelated electrogenic teleost lineages (orders Gymnotiformes and Mormyriformes) and in one non‐electrogenic South American catfish species (order Siluriformes). Electric organs evolved eight times independently among teleosts: five of them among the ostariophysans (once in the gymnotiform ancestor and in four siluriform lineages), once in the common ancestor of Mormyriformes, and in two uranoscopids. With the exception of two uranoscopid genera, for which no electroreceptive capabilities have been discovered so far, all electric organs evolved as an extension of a pre‐existing electroreceptive (ampullary) condition. It is suggested that plesiomorphic electric organ discharges (EODs) possessed a frequency spectrum that fully transgressed the tuning curve of ampullary receptors, i.e. a signal such as a long lasting monophasic pulse. Complex EOD waveforms appeared as a derived condition among electric fish. EODs are under constant evolutionary pressure to develop an ideal compromise between a function that enhances electrolocation and electrocommunication capabilities, and thereby ensures species identity through sexual and behavioural segregation, and minimizes the risk of predation.     

Comparative cytomorphology of skin, lymph node, liver and bone marrow in patients with lepromatous leprosy1

OBJECTIVE: The aim of this study was to compare the cytological changes in skin, lymph nodes, liver and bone marrow in patients with lepromatous leprosy. METHODS: Skin lesion, lymph node, liver and bone marrow aspirates were analysed. May-Grunwald-Giemsa (MGG) and Ziehl-Neelsen (Z-N) stains were employed. Comparative cytomorphology was studied. RESULTS: Twenty patients with lepromatous leprosy were studied. Lepra cells (LC) predominated in the skin aspirates of 12 patients with lepromatous leprosy (LL), lymphocytes accompanied LC in eight patients with borderline-lepromatous (BL) leprosy. Three patients of LL leprosy and two of BL leprosy in type 2 reaction additionally had numerous neutrophils. Two patterns of lymph node aspirates were seen: partial replacement with few LC in a reactive lymphoid background (10), complete replacement with either only LC or LC in a background of degenerating neutrophils (10), the latter a feature of type 2 reaction. Liver aspiration was performed in seven patients and of bone marrow in eight patients. Occasional LC were present in five liver-aspirated patients, steatosis and Kupffer cell hyperplasia in four patients, and myelopoiesis in two patients. Bone marrow smears invariably had occasional LC and a relative increase in mature plasma cells; sea-blue histiocytes were seen in six patients. CONCLUSION: Lepra cells predominated in skin and lymph node aspirates with complete replacement. In comparison, liver, bone marrow and lymph node aspirates with partial replacement were dominated by a preponderance of cells native to these organs with only few or occasional LC.     

Effects of metopirone on the structure of endocrine glands in the male lizard,Cnemidophorus l. lemniscatus (L.)

Summary Adrenals, pituitary glands, thyroids, testes and kidneys of metopirone-treated and control male lizards were studied by light microscopy. Pituitary-interrenal axis: A great hypertrophy and hyperplasia of the interrenal cells and the pituitary corticotrophs were found in the experimental group. Pituitary-thyroid axis: Metopirone-treated animals showed a moderate hypertrophy and degranulation of pituitary thyrotrophs, and signs of uneven hyperactivity of the thyroid. Pituitary-testicular axis: By effect of metopirone, a marked regression of pituitary interstitiotrophs and a virtual disappearance of the testicular interstitial gland took place. The second portion of the kidney sexual segments appeared degranulated as in castrated animals. The pituitary folliculotrophs and the seminiferous epithelium of the testis did not show alterations.     

Ultrastructure of the sexual segments of the kidney in male and female lizards,Cnemidophorus l. lemniscatus (L.)

Summary Kidneys of adult male and female lizards were studied by electron microscopy, in order to understand the ultrastructure of the collecting duct and a differentiated part thereof, the sexual segment, which is an important accessory sexual organ. First portion of sexual segment in males: The cells are filled with large secretory granules of a wide range of opacities. The granular endoplasmic reticulum is abundant; basal formations of superimposed flat cisternae are frequent. Distended vesicles and microvesicles prevail in the supranuclear, well developed Golgi apparatus. Evidences indicate that secretion of these cells is holocrine. Second portion of sexual segment in males: All of the secretory granules are apical in location and relatively electron-opaque; they show a denser core. This core is formed by a substance which, after lying in contact with ribosomes, enters the secretory vesicles of the highly developed Golgi apparatus. A lighter substance is then condensed around it. The secretion of the granules is merocrine. The granular endoplasmic reticulum is very abundant in these cells, but basal ergastoplasmic formations are lacking. Sexual segment in females: The cells show features similar to those of the male first portion, but they are smaller. Undifferentiated collecting duct: Most of the cells are mucigenic. They have small ovoid, apical secretory granules. The density of the granules varies from cell to cell; when they are electron-lucent, they exhibit laminar or dotted opaque figures. Moderately developed Golgi apparatus and granular endoplasmic reticulum, as well as elongated mitochondria, occur in mucigenic cells. Intercalated among the latter are non-secretory cells. They have very abundant mitochondria, numerous microvilli, many pinocytic and smooth-membrane vesicles, whereas the organelles participating in synthetic processes are poorly developed; their function is most likely related to active solute transport.