RESUMO
Molting is induced in decapod crustaceans via multiple leg autotomy (MLA) or eyestalk ablation (ESA). MLA removes five or more walking legs, which are regenerated and become functional appendages at ecdysis. ESA eliminates the primary source of molt-inhibiting hormone (MIH) and crustacean hyperglycemic hormone (CHH), which suppress the production of molting hormones (ecdysteroids) from the molting gland or Y-organ (YO). Both MLA and ESA are effective methods for molt induction in Gecarcinus lateralis. However, some G. lateralis individuals are refractory to MLA, as they fail to complete ecdysis by 12weeks post-MLA; these animals are in the "blocked" condition. Quantitative polymerase chain reaction was used to quantify mRNA levels of neuropeptide and mechanistic target of rapamycin (mTOR) signaling genes in YO, eyestalk ganglia (ESG), thoracic ganglion (TG), and brain of intact and blocked animals. Six of the seven neuropeptide signaling genes, three of four mTOR signaling genes, and Gl-elongation factor 2 (EF2) mRNA levels were significantly higher in the ESG of blocked animals. Gl-MIH and Gl-CHH mRNA levels were higher in the TG and brain of blocked animals and levels increased in both control and blocked animals in response to ESA. By contrast, mRNA levels of Gl-EF2 and five of the 10 MIH signaling pathway genes in the YO were two to four orders of magnitude higher in blocked animals compared to controls. These data suggest that increased MIH and CHH synthesis in the ESG contributes to the prevention of molt induction by MLA in blocked animals. The up-regulation of MIH signaling genes in the YO of blocked animals suggests that the YO is more sensitive to MIH produced in the ESG, as well as MIH produced in brain and TG of ESA animals. Both the up-regulation of MIH signaling genes in the YO and of Gl-MIH and Gl-CHH in the ESG, TG, and brain appear to contribute to some G. lateralis individuals being refractory to MLA and ESA.
Assuntos
Proteínas de Artrópodes/metabolismo , Braquiúros/fisiologia , Glândulas Exócrinas/inervação , Gânglios dos Invertebrados/metabolismo , Regulação da Expressão Gênica no Desenvolvimento , Hormônios de Invertebrado/metabolismo , Modelos Neurológicos , Proteínas do Tecido Nervoso/metabolismo , Animais , Proteínas de Artrópodes/genética , Oceano Atlântico , Braquiúros/crescimento & desenvolvimento , Encéfalo/crescimento & desenvolvimento , Encéfalo/metabolismo , República Dominicana , Ecdisteroides/biossíntese , Ecdisteroides/metabolismo , Glândulas Exócrinas/crescimento & desenvolvimento , Glândulas Exócrinas/metabolismo , Olho/crescimento & desenvolvimento , Olho/inervação , Olho/metabolismo , Gânglios dos Invertebrados/crescimento & desenvolvimento , Hormônios de Invertebrado/genética , Masculino , Muda , Proteínas do Tecido Nervoso/genética , Especificidade de Órgãos , Fatores de Alongamento de Peptídeos/genética , Fatores de Alongamento de Peptídeos/metabolismo , Transdução de Sinais , Serina-Treonina Quinases TOR/genética , Serina-Treonina Quinases TOR/metabolismo , Cavidade Torácica/crescimento & desenvolvimento , Cavidade Torácica/inervação , Cavidade Torácica/metabolismoRESUMO
Exocrine glands play important role in social organization of insects, such as caste and inter-caste differentiation. Due their functional and structural plasticity, morphological studies on such glands contribute to better understanding the biology of social bees. Therefore, the aim of the study was to characterize the sequence of the post-embryonic development of intramandibular glands of Friesella schrottkyi (Friese, 1900) (Hymenoptera: Apidae) workers using histological and histochemical analyses. The mandibles of pupae at different developmental stages and newly emerged adults were analyzed. The intramandibular glands of F. schrottkyi presented two types: class I glands, in the mandible epidermis and class III glands, inside the mandible cavity that open onto external surface. The intramandibular glands of F. schrottkyi developed during the transition from the prepupae to the white-eyed pupae, as shown by the morphological changes. Black-eyed pupae of F. schrottkyi presented fully developed intramandibular glands.
As glândulas exócrinas desempenham importantes funções na organização social dos insetos, como a diferenciação de castas e inter-castas. Devido à sua plasticidade estrutural e funcional, estudos morfológicos destas glândulas contribuem para o melhor entendimento da biologia das abelhas sociais. Por isso, o objetivo deste estudo foi acompanhar o desenvolvimento pós-embrionário das glândulas intramandibulares de operárias da abelha sem ferrão Friesella schrottkyi (Friese, 1900) (Hymenoptera: Apidae) com análises histológicas e histoquímicas. As mandíbulas das pupas em diferentes estágios do desenvolvimento e operárias recém-emergidas foram analisadas. As glândulas intramandibulares de F. schrottkyi são divididas em dois tipos: glândulas da classe I na epiderme da mandíbula e da classe III, inseridas na cavidade da mandíbula que se abrem na superfície externa. As glândulas intramandibulares de F. schrottkyi se desenvolvem durante a transição de pré-pupa para pupa de olho branco como observado pelas alterações morfológicas nas células. As pupas de olhos pretos de F. schrottkyi apresentaram glândulas intramandibulares completamente desenvolvidas.
Assuntos
Animais , Abelhas , Glândulas Exócrinas/crescimento & desenvolvimento , Mandíbula/crescimento & desenvolvimentoRESUMO
Exocrine glands play important role in social organization of insects, such as caste and inter-caste differentiation. Due their functional and structural plasticity, morphological studies on such glands contribute to better understanding the biology of social bees. Therefore, the aim of the study was to characterize the sequence of the post-embryonic development of intramandibular glands of Friesella schrottkyi (Friese, 1900) (Hymenoptera: Apidae) workers using histological and histochemical analyses. The mandibles of pupae at different developmental stages and newly emerged adults were analyzed. The intramandibular glands of F. schrottkyi presented two types: class I glands, in the mandible epidermis and class III glands, inside the mandible cavity that open onto external surface. The intramandibular glands of F. schrottkyi developed during the transition from the prepupae to the white-eyed pupae, as shown by the morphological changes. Black-eyed pupae of F. schrottkyi presented fully developed intramandibular glands.(AU)
As glândulas exócrinas desempenham importantes funções na organização social dos insetos, como a diferenciação de castas e inter-castas. Devido à sua plasticidade estrutural e funcional, estudos morfológicos destas glândulas contribuem para o melhor entendimento da biologia das abelhas sociais. Por isso, o objetivo deste estudo foi acompanhar o desenvolvimento pós-embrionário das glândulas intramandibulares de operárias da abelha sem ferrão Friesella schrottkyi (Friese, 1900) (Hymenoptera: Apidae) com análises histológicas e histoquímicas. As mandíbulas das pupas em diferentes estágios do desenvolvimento e operárias recém-emergidas foram analisadas. As glândulas intramandibulares de F. schrottkyi são divididas em dois tipos: glândulas da classe I na epiderme da mandíbula e da classe III, inseridas na cavidade da mandíbula que se abrem na superfície externa. As glândulas intramandibulares de F. schrottkyi se desenvolvem durante a transição de pré-pupa para pupa de olho branco como observado pelas alterações morfológicas nas células. As pupas de olhos pretos de F. schrottkyi apresentaram glândulas intramandibulares completamente desenvolvidas.(AU)
Assuntos
Animais , Glândulas Exócrinas/crescimento & desenvolvimento , Abelhas , Mandíbula/crescimento & desenvolvimentoRESUMO
Avoiding predation is critical to survival of animals; chemical defenses represent a common strategy among amphibians. In this study, we examined histologically the morphology of skin glands and types of secretions related to chemical skin defense during ontogeny of Rhinella arenarum. Prior to metamorphic climax the epidermis contains typical bufonid giant cells producing a mucous substance supposedly involved in triggering a flight reaction of the tadpole school. An apical layer of alcianophilic mucus covers the epidermis, which could produce the unpleasant taste of bufonid tadpoles. Giant cells disappear by onset of metamorphic climax, when multicellular glands start developing, but the apical mucous layer remains. By the end of climax, neither the granular glands of the dorsum nor the parotoid regions are completely developed. Conversely, by the end of metamorphosis the mucous glands are partially developed and secrete mucus. Adults have at least three types of granular glands, which we designate type A (acidophilic), type B (basophilic) and ventral (mucous). Polymorphic granular glands distribute differently in the body: dorsal granular glands between warts and in the periphery of parotoids contain protein; granular glands of big warts and in the central region of parotoids contain catecholamines, lipids, and glycoconjugates, whereas ventral granular glands produce acidic glycoconjugates. Mucous glands produce both mucus and proteins. Results suggest that in early juveniles the chemical skin defense mechanisms are not functional. Topographical differences in adult skin secretions suggest that granular glands from the big warts in the skin produce similar toxins to the parotoid glands.
Assuntos
Anuros/anatomia & histologia , Anuros/crescimento & desenvolvimento , Epiderme/crescimento & desenvolvimento , Metamorfose Biológica/fisiologia , Pele/anatomia & histologia , Pele/crescimento & desenvolvimento , Animais , Epiderme/anatomia & histologia , Glândulas Exócrinas/anatomia & histologia , Glândulas Exócrinas/crescimento & desenvolvimento , Feminino , Imuno-Histoquímica , Masculino , Comportamento PredatórioRESUMO
Protection against predators and competitors is one of the main concerns of termite colonies, which developed a specialised defensive caste, the soldiers. However, soldiers are rare or even missing in several lineages of termites, while workers often develop new defence strategies especially in soil-feeding species. Here, we describe the morphology and ultrastructure of the autothysis-associated glands of Neocapritermes taracua workers and report their age-related changes in structure. The defensive glands of N. taracua workers consist of a pair of labial and a pair of crystal glands, whose secretions mix together through autothysis. Autothysis always occurs at the line of weakness connecting the anterior parts of the crystal-bearing pouches. The crystal glands consist of groups of bicellular secretory units (secretory and corresponding canal cells) which secrete the blue crystal material into external pouches. Their secretory activity is maximal in the middle of worker life, and is considerably lower in very young and old workers. The labial glands are composed of two types of secretory cells: the central and the parietal cells. While the central cells are developed similarly to other termites and secrete proteinaceous secretion into labial gland ducts, the parietal cells develop proteinaceous granules which may eventually bud off the cells. The secretory function of parietal cells is so far unique to N. taracua and differs from other termite species in which they are only responsible of water uptake by acini. The defensive device of N. taracua is truly exceptional as it involves a new gland and a previously undescribed function for parietal cells, being a remarkable example of evolution of morphological innovation.
Assuntos
Isópteros/crescimento & desenvolvimento , Isópteros/ultraestrutura , Fatores Etários , Animais , Glândulas Exócrinas/crescimento & desenvolvimento , Glândulas Exócrinas/ultraestrutura , Guiana Francesa , Microscopia Eletrônica de Varredura , Microscopia Eletrônica de TransmissãoRESUMO
BACKGROUND: Snake bite is a neglected public health problem in communities in rural areas of several countries. Bothrops jararaca causes many snake bites in Brazil and previous studies have demonstrated that the pharmacological activities displayed by its venom undergo a significant ontogenetic shift. Similarly, the venom proteome of B. jararaca exhibits a considerable variation upon neonate to adult transition, which is associated with changes in diet from ectothermic prey in early life to endothermic prey in adulthood. Moreover, it has been shown that the Brazilian commercial antibothropic antivenom, which is produced by immunization with adult venom, is less effective in neutralizing newborn venom effects. On the other hand, venom gland transcripts of newborn snakes are poorly known since all transcriptomic studies have been carried out using mRNA from adult specimens. METHODS/PRINCIPAL FINDINGS: Here we analyzed venom gland cDNA libraries of newborn and adult B. jararaca in order to evaluate whether the variability demonstrated for its venom proteome and pharmacological activities was correlated with differences in the structure of toxin transcripts. The analysis revealed that the variability in B. jararaca venom gland transcriptomes is quantitative, as illustrated by the very high content of metalloproteinases in the newborn venom glands. Moreover, the variability is also characterized by the structural diversity of SVMP precursors found in newborn and adult transcriptomes. In the adult transcriptome, however, the content of metalloproteinase precursors considerably diminishes and the number of transcripts of serine proteinases, C-type lectins and bradykinin-potentiating peptides increase. Moreover, the comparison of the content of ESTs encoding toxins in adult male and female venom glands showed some gender-related differences. CONCLUSIONS/SIGNIFICANCE: We demonstrate a substantial shift in toxin transcripts upon snake development and a marked decrease in the metalloproteinase P-III/P-I class ratio which are correlated with changes in the venom proteome complexity and pharmacological activities.
Assuntos
Bothrops/genética , Venenos de Crotalídeos/química , Proteoma/análise , Transcriptoma , Animais , Animais Recém-Nascidos , Bothrops/crescimento & desenvolvimento , Brasil , Glândulas Exócrinas/química , Glândulas Exócrinas/crescimento & desenvolvimento , Feminino , Regulação da Expressão Gênica no Desenvolvimento , Biblioteca Gênica , MasculinoRESUMO
The male mucus gland is present in all species of bees, exception for meliponines. In bees, the function of themucus glands is not certain so far and its contribution to form the female espermatecal fluid is not assured.With the aim to contribute to the knowledge of the mucus gland in bees we carried out a histochemical studyof the gland in mature, adult males of Bombus morio, focusing on the histochemical nature of the secretion.The males were collected around the forest fragments into UFSCar, Campus Sorocaba. The glands werefixed and analysed under routine microscopy and for histochemistry techniques: Periodic Acid Schiff (PAS),Bromophenol Blue (BB), Sudan Black (SB) and Critical Electrolyte Concentration (CEC) variant. The resultsshowed that the mucus gland is constituted by a pair of large, thick tubular structures, which presented theirdistal portion more dilated and corn shaped. The glandular cells are columnar and in the apical portion presentseveral apocrine vesicles being released into the gland lumen. The histochemistry showed that gland secretionis very complex and contains protein (BB), neutral polysaccharide (PAS), as well as lipid (SB). The luminalgland secretion presents a background of homogenous content, presenting little dark dots stained by alltechniques used for this work. The investigation of the nucleolar activity (CEC) showed that the mucus glandepithelium is evolved in protein synthesis, presenting nucleoli developed and much RNA in the cytoplasm.
Assuntos
Animais , Masculino , Glândulas Exócrinas , Muco , Muco/química , Abelhas , Glândulas Exócrinas/crescimento & desenvolvimento , MicroscopiaRESUMO
The sand fly Lutzomyia longipalpis (Lutz & Neiva) (Diptera: Psychodidae: Phlebotominae) is the main vector of American visceral leishmaniasis. Adult males produce a terpenoid sex pheromone that in some cases also acts as male aggregation pheromone. We have analyzed the correlation between male pheromone production levels and pheromone gland cell morphogenesis after adult emergence from pupae. The abdominal tergites of L. longipalpis males were dissected and fixed in glutaraldehyde for transmission electron microscopy, or the pheromone was extracted in analytical grade hexane. Pheromone chemical analysis was carried out at 3- to 6-h intervals during the first 24 h after emergence and continued daily until the seventh day. All extracts were analyzed by gas chromatography. For the morphological analysis, we used insects collected at 0-6, 9-12, 12-14, and 96 h after emergence. Ultrastructural data from 0- to 6-h-old adult males revealed smaller pheromone gland cells with small microvilli at the end apparatus. Lipid droplets and peroxisomes were absent or very rare, but a large number of mitochondria could be seen. Lipid droplets started to appear in the gland cells cytoplasm approximately 9 h after adult emergence, and their number and size increased with age, together with the presence of several peroxisomes, suggesting a role for these organelles in pheromone biosynthesis. At 12-15 h after emergence, the lipid droplets were mainly distributed near the microvilli but were smaller than those in mature older males (4 d old). Pheromone biosynthesis started around 12 h after emergence and increased continuously during the first 3 d, stabilizing thereafter, coinciding with the period when males are more able to attract females.
Assuntos
Psychodidae/crescimento & desenvolvimento , Psychodidae/ultraestrutura , Atrativos Sexuais/biossíntese , Animais , Brasil , Glândulas Exócrinas/crescimento & desenvolvimento , Glândulas Exócrinas/metabolismo , Glândulas Exócrinas/ultraestrutura , Masculino , Microscopia Eletrônica de Transmissão , Morfogênese , Atrativos Sexuais/análise , Terpenos/análiseRESUMO
Biochemical studies revealed that the activity of some hydrolytic enzymes from the venom glands of honey bee Apis mellifera was higher in workers of 14 days of age than in those of 40 days. Among these enzymes, the highest activity was recorded for acid phosphatase, which was cytochemically detected throughout the length of the secretory filament and surrounding the canaliculi of the distal region of the reservoir. The acid phosphatase was considered to be a typical secretion product, since it was present in the cytoplasm as well as in the canaliculi of the secretory cells.
Assuntos
Venenos de Abelha/enzimologia , Abelhas/enzimologia , Abelhas/crescimento & desenvolvimento , Glândulas Exócrinas/enzimologia , Glândulas Exócrinas/crescimento & desenvolvimento , AnimaisRESUMO
Different from the classic view, the prostate is not a gland exclusive to the male, also being an organ of the female genital system presenting morphofunctional similarity between human and rodent. Thus structural, ultrastructural, morphometric-stereological features of the female prostate (Skene's paraurethral gland) and steroid serological levels were evaluated during young, adult, and senile ages in the Mongolian gerbil. The morphofunctional precocity of the female gland in comparison with the male gland occurring in young gland is probably associated with the female circulating steroid levels. The hormonal imbalance in senesce coincides with its susceptibility to histopathological lesions, such as epithelial hypertrophy, metaplasia, and intraepithelial neoplasia. Differently than that of males, the aging degeneration of the female gland involves the accumulation of lipofuscin granules. However, the alterations in senile prostate did not damage its functionality. These analyses reinforce the use of this experimental model for the comprehension of glandular morphofunctional aspects with special attention to senescence. Thus, the appreciation of this organ becomes relevant to avoid future discomfort to women's health.
Assuntos
Envelhecimento/fisiologia , Glândulas Exócrinas/ultraestrutura , Hormônios Esteroides Gonadais/sangue , Próstata/ultraestrutura , Uretra/ultraestrutura , Envelhecimento/sangue , Animais , Desidroepiandrosterona/sangue , Estradiol/sangue , Glândulas Exócrinas/crescimento & desenvolvimento , Glândulas Exócrinas/fisiologia , Feminino , Masculino , Morfogênese/fisiologia , Caracteres Sexuais , Testosterona/sangueRESUMO
Morphological, chemical and developmental aspects of the Dufour gland in some eusocial bees (Hymenoptera, Apidae): a review. The present revision focused on the more recent data about the Dufour gland in some eusocial bees, taking in account general aspects of its morphology, secretion chemical nature, bio-synthetic pathway and development. Many functions have been attributed to this gland in eusocial bees, but none are convincing. With the new data about this gland, not only the secretion chemical pathway of the Dufour gland may be reasonable understood, as its function in some eusocial bees, especially Apis mellifera Linné, 1758, which has been extensively studied in the last years.
Aspectos morfológicos, químicos e do desenvolvimento da glândula de Dufour em algumas abelhas eussociais (Hymenoptera, Apidae): revisão. Esta revisão aborda os mais recentes dados sobre a glândula de Dufour em algumas abelhas eussociais, considerando aspectos gerais da sua morfologia, do seu desenvolvimento, da natureza química da sua secreção, assim como sua via bio-sintética. Muitas funções têm-se atribuído à glândula de Dufour nas abelhas eussociais, mas nenhuma suficientemente convincente. Os novos dados a respeito dessa glândula permitem não só conhecer razoavelmente bem a via bio-sintética como a função da secreção da glândula de Dufour em algumas abelhas eussociais, especialmente em Apis mellifera Linné, 1758, a qual tem sido extensivamente estudada nos últimos anos.
Assuntos
Animais , Abelhas , Glândulas Exócrinas/anatomia & histologia , Glândulas Exócrinas/crescimento & desenvolvimento , Glândulas Exócrinas , FeromôniosRESUMO
Different histochemical techniques were applied to examine the morphological features of the secretory cells of hypopharyngeal glands in the wasp Polistes versicolor. The results showed that most analyzed individuals present active glands with secretion stored in the cytoplasm. In some glands, morphological analyses revealed the presence of degenerative characteristics. Analyses of cellular integrity, however, did not detect dead cells. The results showed that, in P. versicolor, the development and regression of the hypopharyngeal glands were not age related, unlike glands of social bees.
Assuntos
Glândulas Exócrinas/citologia , Glândulas Exócrinas/metabolismo , Vespas/anatomia & histologia , Fosfatase Ácida/análise , Fatores Etários , Animais , Glândulas Exócrinas/crescimento & desenvolvimento , Glândulas Exócrinas/patologia , Hipofaringe/anatomia & histologia , Necrose/patologia , Vesículas Secretórias/metabolismo , Coloração e Rotulagem , Vespas/crescimento & desenvolvimentoRESUMO
Serous (poison) cutaneous glands of the leptodactylid species Physalaemus albonotatus and Leptodactylus chaquensis were compared using light and transmission electron microscopy. Glands in the two species share structural traits common in anurans, including the peripheral contractile sheath (myoepithelium) and the syncytial secretory unit that produces, stores, and modifies the poison. At the ultrastructural level, early steps of poison production are also similar and fit the usual path of proteosynthesis, involving rough endoplasmic reticulum (RER) and Golgi stacks (dictyosomes) in the peripheral syncytial cytoplasm. However, several differences are obvious during the maturational processes that lead post-Golgian products to their ultimate ultrastructural traits. In P. albonotatus, the dense product released from the dictyosomes acquires a thick repeating substructure, which, however, becomes looser in the inner portion of the syncytium. In L. chaquensis, serous maturation involves gradual condensation, and opaque, somewhat "vacuolized" granules are formed. These different maturational paths expressed during poison manufacturing in the two species agree with the polyphyletic origin of the family Leptodactylidae. On the other hand, data collected for P. albonotatus fit previous findings from P. biligonigerus and stress the view that poisons produced by congeneric species share similar (or identical) ultrastructural features.
Assuntos
Anuros/anatomia & histologia , Glândulas Exócrinas/ultraestrutura , Complexo de Golgi/ultraestrutura , Vesículas Secretórias/ultraestrutura , Pele/ultraestrutura , Venenos de Anfíbios/biossíntese , Animais , Anuros/fisiologia , Glândulas Exócrinas/crescimento & desenvolvimento , Complexo de Golgi/metabolismo , Vesículas Secretórias/metabolismo , Fenômenos Fisiológicos da PeleRESUMO
Ponderal, morphometric and morphological assessments were used to study the Syrian golden hamster pancreas development during the first 70 days of postnatal life. The body mass increased 41.74 times in a single growth phase and a mean duplication time calculated by linear equation y = 1.76 x - 1.87 (r2 = 0.95), was 13.4 days. The pancreatic mass increased 44.60 times in two growth phases, the first from 2 to 21 days and the second from 28 to 70 days of age. The exponential equation obtained by regression analysis for these periods, were: y = 5.21. e (0.1810.x) (r2 = 0.95) and y = 156.64. e(0.0094.x (r2 = 0.72), respectively, and the calculated duplication times were: 3.8 and 73.7 days, respectively. This marked pancreatic growth was due to the increase in all theirs morphological compartments, especially of the acini. An inverse relationship was observed in the volume density evolution between the acini and the stroma, with a 2.30 times increase in the fraction of pancreatic volume occupied by the acini and a 0.26 times reduction in the connective tissue spaces during studied period. The volume density of pancreatic islets increased 4.47 times from 21 to 35 days of age. The morphological analysis showed a significant increase in the height and width of the acinar cells and in the size of the acini especially from 14 to 21 days of age, a relative reduction in the stromal volume, an increase in the size of the pancreatic islets and the end of parenchymal cell maturation and lobar and lobular organization, so glandular maturity was obtained.