Efeitos de três análogos do hormônio juvenil aplicados em bicho-da-seda, Bombyx mori L. (Lepidoptera: Bombycidae)

Análogos do hormônio juvenil (AHJ) têm sido testados como reguladores de crescimento de Bombyx mori L., com vistas ao incremento da produção de casulos. Esses produtos, quando aplicados em doses adequadas, prolongam o período larval. Os efeitos da aplicação de AHJ podem variar com o produto, a linhagem e o momento de aplicação. Este estudo teve por objetivo avaliar o efeito da aplicação tópica, em diferentes momentos, de três análogos do hormônio juvenil sobre o crescimento dos insetos e a produção de seda da linhagem brasileira C115xN108 do bicho-da-seda. Os produtos piriproxifem, metoprene e fenoxicarbe foram aplicados em larvas do bicho-da-seda a 24h, 48h, 72h e 96h após o início do quinto ínstar (HQI) e seus efeitos sobre características biológicas larvais e adultas e a produção de seda foram avaliados. Independentemente do momento de aplicação, os três produtos afetaram todos os parâmetros avaliados. A reserva de nutrientes acumulada durante o período larval prolongado dos insetos tratados foi destinada ao crescimento das glândulas sericígenas e, também, convertida em peso corporal, com conseqüentes incrementos na produção de seda. Aplicações entre 48 e 72 HQI provocaram os maiores incrementos na biomassa e na produção de casulos de B. mori. Variações no momento de aplicação de 24h e 96h não influenciaram a emergência ou a oviposição de adultos de B. mori, nem a viabilidade dos ovos.

Influence of the insecticide pyriproxyfen on the flight muscle differentiation of Apis mellifera (Hymenoptera, Apidae)

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Protein content and electrophoretic profile of fat body and ovary extracts from workers of Melipona quadrifasciata anthidioides (Hymenoptera, Meliponini)

Workers of Melipona quadrifasciata anthidioides (Lepeletier, 1836) develop their ovaries and lay eggs, therefore the production of vitellogenin is expected. In electrophoretic profiles only fat body extracts from nurse workers and ovary extracts from newly-emerged workers show protein with molecular mass similar to vitellogenin. However, an increase in the protein content was detected in forager fat body. This increase was attributed to storage of vitellogenin or other proteins in the previous phase and not discharged into the hemolymph or to an effect of the increased titre of juvenile hormone in this phase of worker life over the fat body functioning.

Efeitos da aplicação tópica de hormônio juvenil sobre o desenvolvimento dos ovários de larvas de operárias de Apis mellifera Linnaeus (Hymenoptera, Apidae)

A influência do hormônio juvenil sobre o desenvolvimento do ovário de larvas de operárias de Apis mellifera foi analisada levando em conta a determinação trófica das castas, segundo a qual a alimentação larval é controlada pelas operárias de maneira a promover uma diferenciação de castas controlada pela produção e disponibilidade desse hormônio. A hipótese testada é que a ação do hormônio juvenil seja capaz de proteger ou prevenir a degeneração nos ovários das larvas de operárias. Foi feita aplicação tópica de 1 ml de hormônio dissolvido em hexano na concentração de 1 mg/ml do segundo até o quinto dia de vida larval, e a morfologia dos ovários avaliada nos dias subseqüentes à aplicação até ao sexto dia de vida larval. Como controles foram utilizadas larvas nas quais se aplicou 1 ml de hexano e larvas que não receberam nenhum tratamento. Constatou-se que o efeito do hormônio juvenil varia conforme a idade larval em que é aplicado e que este efeito foi maior quando a aplicação foi feita no terceiro dia de vida larval.

Ontogenia da casta de soldados no cupim praga Heterotermoes tenuis (Isoptera, Rhinotermitidae)

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Contribuição à análise do processo de africanização de Apis mellifera (Hymenoptera, apidae): características do desenvolvimento das glândulas de Dufour e de veneno

Pós-graduação em Ciências Biológicas (Biologia Celular e Molecular) - IBRC

Desenvolvimento e produção de seda do Bombyx mori L. exposto a análogos do hormônio juvenil

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Desempenho reprodutivo e diferenciação gonadal em piau-três-pintas, Leporinus friderici, Bloch 1794

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Hormone profile in juvenile systemic lupus erythematosus with previous or current amenorrhea

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Progression of articular and extraarticular damage in oligoarticular juvenile idiopathic arthritis

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

INFLUENCE OF DIETARY-PROTEIN INTAKE AND RECOMBINANT HUMAN SOMATOTROPIN ADMINISTRATION ON GROWTH AND BODY-COMPOSITION OF JUVENILE TAMBACU (A PIARACTUS-MESOPOTAMICUS X COLOSSOMA-MACROPOMUM CROSS)

This experiment was undertaken to study the interaction between level of dietary protein and recombinant human somatotropin (rhGH) administration on performance and body composition of juvenile tambacu (a crossbred Brazilian fish). A total of 72 juvenile tambacu, initially weighing and measuring (mean +/- s.e.m.) 23 +/- 2 g and 9 +/- 0.5 cm, respectively, were randomly divided into 18 groups of 4 fish each. Water temperature was 28 degrees C. Triplicate groups received one of two levels of dietary protein (15 and 30% as fed basis) and one of 3 doses of rhGH (0, 2 and 4 mu g/g) via intraperitoneal injection twice a week for 6 weeks, using a randomized complete block design. Somatotropin was noted to stimulate linear and body weight gain. The higher protein level supported increased growth in weight and length, but there was no interaction between protein level and rhGH dose for either parameter. Protein efficiency ratio and percentage protein deposited showed higher values on diets containing 15% protein. Somatotropin treatment did not significantly affect body composition, but there was a trend towards improved protein retention and reduced carcass lipid. In conclusion, the results of this experiment suggest that rhGH is able to stimulate linear gain in tambacu.

Non-ventilation during early incubation in combination with dexamethasone administration during late incubation: 1. Effects on physiological hormone levels, incubation duration and hatching events

This study investigated the effect of non-ventilation of the incubator during the first 10 days of incubation and its combination with dexamethasone administration at day 16 or 18 of incubation on hatching parameters and embryo and post-hatch chick juvenile physiology. A total of 2400 hatching eggs produced by Cobb broiler breeders were used for the study. Blood samples were collected at day 18 of incubation, at internal pipping stage (IP), at the end of hatch (day-old chick) and at 7-daypost-hatch for T-3, T-4 and corticosterone levels determination. From 448 to 506 h of incubation, the eggs were checked individually in the hatcher every 2 h for pipping and hatching. The results indicate that non-ventilation during the first 10-day shortened incubation duration up to IP, external pipping (EP) and hatch, had no effect on hatchability and led to higher T-3 levels at IP but lower corticosterone levels at 7-day-post-hatch. The injection of dexamethasone at days 16 and 18 of incubation affected hatching and blood parameters in both the ventilated and non-ventilated embryos differentially and the effect was dependent on the age of the embryo. Dexamethasone increased T-3 levels and T-3/T-4 ratios but the effect was greater with early non-ventilation of eggs. Dexamethasone decreased hatchability but the effect was greater when injected at day 16 and especially in ventilated embryos. The effects of incubation protocols and dexamethasone treatments during incubation were still apparent in the hatched chicks until 7 days of age. The changes in T-3, T-4 and corticosterone levels observed in response to the early incubation conditions and late dexamethasone treatments in this study suggest that incubator ventilation or non-ventilation may influence the hypothalamic-pituitary-adrenal axis (HPA) regulation of stress levels (in terms of plasma corticosterone levels) and thyroid function in the embryo with impact on incubation duration, hatching events and early post-hatch life of the chick. Our results also suggest that some stages of development are more sensitive to dexamethasone administration as effects can be influenced by early incubation protocols. (c) 2006 Elsevier B.V. All rights reserved.

Visceral colouration of Eupemphix nattereri (Anura: Leiuperidae): effects of NDP-α-melanocyte stimulating hormone

Amphibians have melanin-containing cells in visceral organs that are similar to pigmentary cells from the epidermis. Both of them are derived from the ectodermal neural crest. Epidermal cells respond to α-melanocyte stimulating hormone (α-MSH), which is associated to the dispersion of melanin granules within melanocytes. Therefore, our aim was to test whether a non-degradable analogue of the α-MSH changes the superficial colouration of organs of Eupemphix nattereri. The hormone rapidly increases (within 12 hours) the colouration on the surface of the pericardium, heart, testes, nerves of the lumbar plexus, and lumbosacral parietal peritoneum. Colouration increased late (after 24 hours) in the kidneys and mesentery following hormone administration. However, this hormone did not change colouration of intestine, rectum and lungs. Our findings could be explained by the similarities between epidermal and visceral melanocytes, since both cells have a common embryonic origin. Furthermore, the increase in visceral colouration may be related to the dispersion of melanosomes within melanocytes, which causes the darkening of organs. Our results demonstrate for the first time that the visceral colouration is responsive, thereby altering the internal pattern of organs' colouration in anurans. © 2013 Copyright 2013 Unione Zoologica Italiana.

Longitudinal distribution and lateral pattern of megalopal settlement and juvenile recruitment of Carcinus maenas (L.) (Brachyura, Portunidae) in the Mira River Estuary, Portugal

Settlement is a critical process in the life history of crabs, and thus affecting the abundance, distribution and structure of estuarine communities. The spatial pattern of settlement of megalopae of the shore crab Carcinus maenas along a longitudinal estuarine gradient (Mira River Estuary, Portugal) was examined, as well as its effects on the juvenile population. To measure megalopal settlement, four replicate collectors were deployed in six equally spaced stations along the estuarine axis. Juveniles were collected on the same locations with a quadrat randomly deployed on the substrate. To assess fine-scale megalopal settlement within a curved region of the estuary, replicate collectors were deployed on both margins along Moinho da Asneira curve. Megalopae settled differently along the six longitudinal points, with a tendency to attenuate their settlement upstream. Within the curved region, megalopae preferentially settled on the left margin collectors, probably due to the weaker velocity speeds felt on this margin. Concerning the overall juvenile density, there were significant differences among the stations distributed along the estuary, but they did no reflect a longitudinal dispersion attenuation pattern. Size-frequency distribution of the juvenile population showed that the average size is higher on the left margin. Recruits (carapace length between 1.0 mm and 3.4 mm) were more abundant on the upstream stations. Density of early juveniles (3.4 mm-6.5 mm) and juveniles (6.5 mm-10 mm) was more stable throughout the estuary axis than that of recruits. This distribution pattern may result from tidal excursion processes or mechanisms to avoid biotic interactions, such as predation and competition. (c) 2006 Elsevier Ltd. All rights reserved.

Chronic exposure to sub-lethal concentration of a glyphosate-based herbicide alters hormone profiles and affects reproduction of female Jundia (Rhamdia quelen)

This work was carried out to verify the effect of a glyphosate-based herbicide on Jundia hormones (cortisol, 17 beta-estradiol and testosterone), oocyte and swim-up fry production. Earthen ponds containing Jundia females were contaminated with glyphosate (3.6 mg/L); blood samples were collected from eight females from each treatment immediately before, or at 1, 10, 20 30 and 40 days following contamination. A typical post-stress rise in cortisol levels was observed at the 20th and 40th days following exposure to glyphosate. At the 40th day, 17 beta-estradiol was decreased in the exposed females. A similar number of oocytes were stripped out from females from both groups, however, a lower number of viable swim-up fry were obtained from the herbicide exposed females, which also had a higher liver-somatic index (LSI). The results indicate that the presence of glyphosate in water was deleterious to Rhamdia quelen reproduction, altering steroid profiles and egg viability. (c) 2006 Elsevier B.V. All rights reserved.