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1.
Akira Mizoguchi 《Physiological Entomology》2017,42(3):239-245
Many insects undergo diapause to survive adverse seasons. Although the mechanism of diapause induction is the subject of extensive study, that of diapause termination remains poorly understood. In the present study, we show the endocrine processes leading to the termination of pupal diapause in Mamestra brassicae. Diapause of this insect is terminated if the pupae are exposed to a low temperature for several weeks. During this period, the prothoracic glands (PGs) of pupae acquire the potential to secrete sufficient ecdysteroids necessary for inducing adult development. The main endocrine changes observed under the low temperature conditions are: (i) the increase in activity of the PGs in two steps; (ii) the increase in responsiveness of the glands to prothoracicotropic hormone (PTTH); and (iii) two‐step increase in PTTH gene expression in the brain. The timing of the first and second increases in PG activity roughly coincides with that of the two steps of increase in PTTH gene expression, and the timing of the increase in the responsiveness of the PGs to PTTH coincides with the second, larger increase in PTTH gene expression. The ablation of the PGs prior to cooling pupae does not affect the increase in PTTH gene expression, whereas brain removal results in a failure to increase PG activity, strongly suggesting that PTTH is the master regulator of diapause development and termination. 相似文献
2.
Activity of salivary glands in secreting honey‐elaborating enzymes in two subspecies of honeybee (Apis mellifera L) 下载免费PDF全文
Aliaa A. Al‐Sherif Adel M. Mazeed Mohamed A. Ewis Emad A. Nafea El‐Seid E. Hagag Ahmed A. Kamel 《Physiological Entomology》2017,42(4):397-403
The activity of invertase, glucose oxidase and amylase in the cephalic (post‐cerebral) and thoracic salivary glands is determined in Egyptian and Carniolan honeybees (Apis mellifera L). For this purpose, three ages of worker bees are selected for enzyme assays. The results show that the three target enzymes are detected in the two glands during the three worker ages, except invertase, which cannot be detected in the cephalic gland of newly emerged bees of both subspecies. In both glands, the secretion of invertase is highest, followed by amylase and then glucose oxidase. In Carniolan bees, invertase secretion of the cephalic and thoracic glands increases gradually with age. In Egyptian bees, invertase increases with age only in the cephalic gland, whereas, in the thoracic gland, the highest secretion activity is detected in 10–15‐day‐old bees. The highest amounts of glucose oxidase and amylase in the cephalic gland are detected in newly emerged individuals of both Egyptian and Carniolan bees. In the thoracic gland, however, the highest activity of both enzymes is recorded only in newly emerged Egyptian bees. The results are discussed in the light of bee management and biological aspects of the two subspecies. 相似文献
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Mono- and sesqui-terpenes of individual oil glands of Citrus latipes fruits were analyzed for their homogeneity. The effect of oleocellosis, desiccation, Penicillium and Phytophthora infection upon the individual terpene components was investigated and expressed in a discriminant analysis and in canonical variables. Each oil gland contained the entire spectrum of terpenes specific for each species, and the biggest difference in affected glands was due to Penicillium infection. 相似文献
5.
K. L. DAVIES C. WINTERS 《Botanical journal of the Linnean Society. Linnean Society of London》1998,126(4):349-361
The ultrastructure of the labellar epidermis of 13 species of Maxillaria and one hybrid was examined using low-vacuum scanning electron microscopy (SEM). The labellum may be homogeneous and glabrous or papillose, comprising one type of cell only, or heterogeneous with papillae, uniseriate trichomes and/or glands in various combinations. The trichomes are unbranched and multicellular with pointed or truncated tips. Moreover, in some taxa, moniliform trichomes occur, and these are thought to fragment with the formation of pseudopollen. Homogeneous and heterogeneous labellar organization may represent separate evolutionary lines. Preliminary results suggest that labellar features may provide additional taxonomic characters allowing determination of intrageneric affinities. 相似文献
6.
G. De Maeyer-Criel 《Cell and tissue research》1973,144(2):299-308
Résumé Ce travail concerne l'étude morphologique de la glande coquillière non pigmentée ou blanche d'Artemia salina. La structure de celle-ci est comparée à celle de la glande coquillière brune de la même espèce. Les différences sont apparemment plus fondamentales qu'une simple variation de la quantité de produit de sécrétion ou de la pigmentation des cellules.Là où les glandes coquillières brunes formeraient la coque chez les animaux ovipares les glandes coquillières blanches pourraient sécréter les produits nécessaires ou utiles au développement des nauplii chez les animaux ovovivipares.
Morphological study of the white shell gland of Artemia salina leach
Summary The white shell glands of Artemia salina have been investigated. Our results, compared to those obtained in the brown-coloured shell glands, occuring within the same species, reveal differences not only in the aspect of the secretory granules but also in the structure of the nucleus and the cytoplasm. These differences between the two types of glands appear to be more striking than a simple variation in the quantity of secretion or in the pigmentation of the gland. As the brown glands are supposed to contribute to the formation of the egg shells in oviparous animals, the secretion of white glands could favour the development of nauplii in ovoviviparous animals.相似文献
7.
Anatomy of the antennal dorsal organ in female of Neodryinus typhlocybae (Hymenoptera: Dryinidae): A peculiar sensory structure possibly involved in perception of host vibration 下载免费PDF全文
Paola Riolo Nunzio Isidoro Sara Ruschioni Roxana L. Minuz Ferdinando Bin Roberto Romani 《Journal of morphology》2016,277(1):128-137
Neodryinus typhlocybae (Hymenoptera: Dryinidae) is a natural enemy of the planthopper Metcalfa pruinosa, which was introduced from North America into Europe and has become established in various regions as a pest species. Vibrational signals play a crucial role in the communication of M. pruinosa, which appears to be exploited by N. typhlocybae. Scanning and transmission electron microscopy have shown that the antennae of N. typhlocybae females have peculiar and complex sensory structures: deep longitudinal grooves that house long sensilla trichodea, termed here “Antennal Dorsal Organs.” Such structures were not present on male antennae. These sensilla extend for the length of the grooves, without contact with the groove cuticle. Their hair shaft is empty and aporous, and inserted into a specialized socket, underneath which there is a cuticular ampulla‐like chamber. Each sensillum is associated with two sensory neurons: one terminates at the proximal end of the dendritic sheath; the other continues into the sensillum sinus and is enclosed in the dendritic sheath. This second sensory neuron then enters the ampulla‐like chamber through the circular opening, and then terminates with a conspicuous tubular body at the shaft base. The possible involvement of this peculiar structure in the context of host recognition mechanism is discussed. J. Morphol. 277:128–137, 2016. © 2015 Wiley Periodicals, Inc. 相似文献
8.
The glands of Tamarix aphylla: a system for salt recretion or for carbon concentration? 总被引:4,自引:0,他引:4
Yoav Waisel 《Physiologia plantarum》1991,83(3):506-510
During periods of high atmospheric humidity, twigs of Tamarix aphylla (L.) Karst. become covered by an alkaline solution. The pH of that solution fluctuates between 8.0 – 8.5 in the dark and 10.5 during the light hours. Such a solution, produced by the glands, constitutes an efficient trap for atmospheric CO2 . Upon the periodic drop in pH, much of the preabsorbed carbon may gradually be released from the solution. This enriches the immediate surroundings of the twigs with CO2 for prolonged periods of time. The expected concentrations of CO2 , at the boundary layer between the atmosphere and the surfaces of the twigs, are over 1 000 ppm. As net photosynthesis of T. aphylla reaches maximal rates only at CO2 concentrations of above 500 ppm, the plants may benefit from this extra source of carbon and may exploit it for maximal assimilation during the early morning hours. Thus, the "salt glands'of Tamarix , which are liable for the production of the alkaline recretum, may serve a triple purpose: (a) removal of excess salts out of the twigs, (b) provision of a cover of hygroscopic solutes that moistens the twigs and shortens the duration of transpiration, and (c) providing the plants with an environment enriched in CO2 . 相似文献
9.
10.
Mammary analogue secretory carcinoma of the salivary glands has morphological shares molecular similarities to secretory carcinoma of the breast. Here, we report a 46‐year‐old woman who presented with a right submandibular gland mass. Fine needle aspiration differential diagnosis included oncocytosis, oncocytoma, acinic cell carcinoma and mammary analogue secretory carcinoma. We also review the current literature regarding clinical presentation and diagnostic workup of this entity. 相似文献