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.

Cytochemistry of fat body trophocytes and ovaries of workers and queens of Melipona quadrifasciata anthidioides (Hymenoptera: Apidae: Meliponini) during vitellogenesis

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

Vitellogenin content in fat body and ovary homogenates of workers and queens of Melipona quadrifasciata anthidioides during vitellogenesis

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.

Ultrastructural evidences of the occurrence of digestion and absorption of organic solutes in bees ileum (Melipona quadrifasciata anthidioides - Hymenoptera, Apidae)

The ultrastructural aspects of the ileum of Melipona quadrifasciata anthidioides, a stingless bee whose workers obtain their protein requirements from pollen, present morphological evidences of digestion and absorption. These evidences are represented by special relationships between food particles and the bacterial nora present and between their assemblage and the ileum wall, mainly in the ileum three anterior fourths. The apical features of the epithelium also are indicative of organic material absorption.

ULTRASTRUCTURE OF THE ILEUM EPITHELIUM OF MELIPONA QUADRIFASCIATA ANTHIDIOIDES (HYMENOPTERA, APIDAE, MELIPONINAE)

Study of the epithelial morphology of a stingless bee ileum from the pyloric valve to the last portion of high absorptive cells shows that although the bee ileum is an anatomically undifferentiated tube, four types of epithelial cells along the tube (in addition to the valve cells) indicate physiological differentiation. The anterior end seems to be less active in reabsorption, while the posterior region contains cells with typical morphology of an ion pump and permits conclusions about the mechanisms of absorption in the posterior end of the intestine. (C) 1994 Wiley-Liss, Inc.

Electrophoretical studies of proteins of the hypopharyngeal glands and of the larval food of Melipona quadrifasciata anthidioides Lep (Hymenoptera, Meliponinae)

The electrophoretical protein patterns of hypopharyngeal glands, larval food of Melipona, and royal jelly of Apis were compared.Since protein patterns of hypopharyngeal glands from newly emerged workers, brood cell provisioners and foragers are similar to freshly deposited larval food, the identical protein bands probably represent actual gland secretion. This suggests that, as in Apis, the glands secrete proteins to the larval food, and maintain this ability throughout life, although at slightly different intensities, according to the activity of the bees.The similarity on the electrophoretic profiles of the major larval food protein in Apis and Melipona is an interesting finding because of its probable evolutionary significance.

Ultrastructure of haemocytes present during flight muscle differentiation of Melipona quadrifasciata anthidioides, Lepidoptera (Hymenoptera, Apidae)

The present work deals with the ultrastructure of the haemocytes present in the dorsal thoracic region of larvae and pre-pupae of Melipona quadrifasciata anthidioides. This is a region of intense muscular differentiation in this phase of life of the insect. Only plasmatocytes, granulocytes, and adiphoaemocytes were found in this area, all showing signs of being intermediate forms.

Size of fat body trophocytes and the ovarian development in workers and queens of Melipona quadrifasciata anthidioides

The correlation between trophocyte size and ovarian development is negative in workers and positive in queens of Melipona quadrifasciata anthidioides. The nurse workers which have the ovaries in a higher developmental stage, present smaller fat body cells them newly-emerged ones. In newly-emerged and nurse workers the trophocytes seem to be delivering their stored products, among which probably vitellogenin. As in workers the cell size variations do not support the occurrence of proteic synthesis or the increasing in reverses storage after the adult emergence, the products released from the trophocytes must come from cellular reserves remaining from the larval phase. This datum is in agreement with the early and brief vitellogenic phase in the ovaries of this caste. In foragers the trophocyte size seen stabilized. In queens it was verified considerable increasing in the trophocyte size from virgin to physogastric queen, as well as the maintenance of the size during all fertile life of the queen.

Effects of treatment of the fat body trophocytes of Melipona quadrifasciata anthidioides nurse workers and virgin queens in culture by juvenile hormone III and ecdysterone (20-HE)

The fat body (FB) consists of two types of cells: throphocytes and oenocytes. Throphocytes are related to intermediary metabolism storing lipids, carbohydrates, and proteins while oenocytes play role in the lipids and lipoproteins production. The vitellogenin is the precursor of egg yolk (vitelline) and is synthesized on FB. The aim of this work was to analyze the effects of hormones acting in bee reproduction, as juvenile hormone (JH) and ecdisteroids (20 HE) on FB cells, where vitellogenin is synthesized. For the study were chose nurse workers that in Melipona quadrifasciata anthidioides present activated ovaries and produce eggs, and virgin queens whose ovaries are not yet activated, presenting only previtellogenic follicles. FB trophocytes from these classes of bees were cultivated in media containing different amounts of JH and 20-HE. The effects on trophocytes cytoplasm reserves of lipids, proteins, and activity of acid phosphatase were compared by observing preparations from cultured FB, treated and control, by transmission electron microscopy (TEM). The results showed that the hormones effects are related to the bee's caste and functional ovary stage. The role of acid phosphatase on mobilization of the trophocyte reserves was also determined. © 2012 Wiley Periodicals, Inc.

Fat body, hemolymph and ovary routes for delivery of substances to ovary in Melipona quadrifasciata anthidioides: Differences among castes through the use of electron-opaque tracers

The yolk protein precursor, vitellogenin (Vg), in bees is synthesized in the fat body trophocytes, delivered to the hemolymph and ultimately absorbed from there during the vitellogenic phase of oocytes in the active ovary. The routes tracing the material exchange that occurs between the trophocytes and the hemolymph, in addition to the transportation from the hemolymph to the ovarian follicles, were marked by alkaline phosphatase and lanthanum nitrate (LN). Active ovaries from nurse workers and physogastric queens, as well as inactive ovaries of virgin queens, were examined by transmission electron microscopy. The LN permitted better visualization of the routes of exchanges between the organs and the hemolymph. Both methods demonstrate the apparent differences between the phases of the ovary and the bee caste. In inactive ovaries of the virgin queens, the routes from the follicular epithelium to the oocyte remain closed; conversely, they are open in active ovaries of the nurse workers and physogastric queens. The differences between the methods and classes of bees are discussed. © The Author 2013. Published by Oxford University Press [on behalf of The Japanese Society of Microscopy]. All rights reserved.

Relação entre o corpo gorduroso e a vitelogênese em fêmeas de Melipona quadrifasciata anthidioides Lep

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

Vitellogenin content in fat body and ovary homogenates of workers and queens of Melipona quadrifasciata anthidioides during vitellogenesis

Vitellogenin (Vg) is an egg yolk protein that is produced primarily in the fat body of most female insects. In the advanced social structure of eusocial honeybees, the presence of the queen inhibits egg maturation in the workers ovaries. However in the stingless bee Melipona quadrifasciata, the workers always develop ovaries and lay a certain amount of eggs while provisioning the brood cells with larval food during what is known as the worker nurse phase. The present work is a comparative study of the presence of Vg in homogenates of the fat bodies and ovaries of the nurse workers, and the virgin and physogastric queens of M. quadrifasciata. The presence of Vg was determined by sodium dodecyl sulfate polyacrylamide gel electrophoresis and immunoblotting using Apis mellifera anti-egg antibody. Vg was not detected in the fat bodies or ovaries of the workers, but it was found in the ovaries of virgin and physogastric queens and in the fat body of physogastric queens. The results are discussed, taking into account the reproductive state of the individuals and the other possible roles of Vg, such as a storage protein for metoabolism of other organs.

Avaliação do serviço de polinização da abelha mandaçaia melipona quadrifasciata em macieiras.

O cultivo de macieira é uma atividade dependente da polinização cruzada para frutificação e, para tanto, da ação de visitantes florais para a transferência de pólen entre cultivares compatíveis (SALOMÉ; ORTH, 2014). O sucesso da polinização depende de uma série de fatores, entre os quais a eficiência do agente polinizador. A abelha Apis mellifera é a espécie mais comumente encontrada sobre flores de macieira. No entanto, não é a única espécie a realizar o serviço de polinização nos pomares. Segundo Lourdes et al. (1996) existe uma grande diversidade de espécies nativas de abelhas no interior de pomares de macieiras, as quais participam ativamente na polinização. A ação de polinizadores nativos é vista como complementar a realizada por A. mellifera (WITTER et al., 2014), e a descoberta de espécies potenciais para este fim é uma necessidade da pesquisa. Segundo Witter et al. (2014), a preocupação com o desparecimento de polinizadores pelo mundo, gerou inúmeros questionamentos sobre a dependência de uma única espécie de polinizador na agricultura. Embora escassas as informações sobre a utilização de abelhas sem ferrão em polinização de cultivos de importância econômica, há evidências do sucesso da ação de espécies nativas na 21 polinização de algumas culturas agrícolas. Por exemplo, a utilização da abelha mandaçaia Melipona quadrifasciata na polinização de cultivos de tomates possibilitou incremento no número de frutos por planta e melhora na qualidade dos frutos (SANTOS et al., 2009). Em macieira, uma alternativa seria o uso conjunto de abelhas nativas e africanizadas em serviços de polinização. De acordo com Viana et al. (2014) a introdução de colmeias de Melipona quadrifasciata anthidioides juntamente 26 com as de A. mellifera incrementou o número de sementes por fruto e a produção de frutos de macieira. Como a abelha mandaçaia Melipona quadrifasciata quadrifasciata apresenta maior atividade externa em horários de temperaturas mais baixas e de umidades relativas altas (GUIBU; IMPERATRIZ-FONSECA, 1984), diferentes aos apresentados por A. mellifera em macieira (SANTOS et al., 2013), pode haver menor competição entres as espécies pelo recurso floral, o que pode permitir ganhos na polinização de macieiras. Assim, objetivou-se avaliar a ação exclusiva da abelha mandaçaia M. quadrifasciata quadrifasciata na frutificação efetiva de macieiras cultivares Gala Baigent e Fuji Suprema.