The dynamics of energy metabolism in the tick embryo / A dinâmica do metabolismo energético em embriões de carrapato

The cattle tick Rhipicephalus (Boophilus) microplus is an ectoparasite capable of transmitting a large number of pathogens, causing considerable losses in the cattle industry, with substantial damage to livestock. Over the years, important stages of its life cycle, such as the embryo, have been largely ignored by researchers. Tick embryogenesis has been typically described as an energy-consuming process, sustaining cell proliferation, differentiation, and growth. During the embryonic stage of arthropods, there is mobilization of metabolites of maternal origin for the development of organs and tissues of the embryo. Glycogen resynthesis in late embryogenesis is considered as an effective indicator of embryonic integrity. In the cattle tick R.(B. (B.) microplus, glycogen resynthesis is sustained by protein degradation through the gluconeogenesis pathway at the end of the embryonic period. Despite recent advancements in research on tick energy metabolism at the molecular level, the dynamics of nutrient utilization during R. (B.) microplus embryogenesis is still poorly understood. The present review aims to describe the regulatory mechanisms of carbohydrate metabolism during maternal-zygotic transition and identify possible new targets for the development of novel drugs and other control measures against R. (B.) microplus infestations.(AU)

O carrapato bovino Rhipicephalus (B.) microplus é um ectoparasita capaz de transmitir diversos patógenos, sendo responsável por grandes perdas na pecuária pelos danos causados ao gado. Atualmente, muitos estudos têm negligenciado fases importantes do ciclo de vida deste parasita, como a fase embrionária. A embriogênese é classicamente descrita como um processo que demanda um consumo de energia, possibilitando a proliferação celular, diferenciação e crescimento. Além disso, em artrópodes, o estágio da embriogênese é caracterizado pela mobilização de metabolitos de origem materna para o desenvolvimento de novos tecidos e órgãos. A ressíntese de glicogênio no final da embriogênese tem sido descrita em diversas espécies de artrópodes, sendo considerada um indicador de integridade do embrião. No caso do R. (B.) microplus a ressíntese de glicogênio é sustentada pela degradação de proteínas durante a gliconeogênese, no terço final da embriogênese. Apesar dos recentes avanços, no estudo molecular e do metabolismo energético, os mecanismos envolvidos na dinâmica da utilização de diferentes substratos energéticos durante a embriogênese do carrapato R. (B.) microplus ainda é pouco entendido. Diante deste panorama, estudos que descrevam a regulação destes mecanismos e da associação do metabolismo de carboidratos com a transição materno zigótica, pode auxiliar na busca de novos alvos para o desenvolvimento de novos acaricidas e outras intervenções para o controle infestações de R. (B.) microplus.(AU)

Metabolismo de biomoléculas na embriogênese do carrapato Rhipicephalus (Boophilus) microplus / Metabolism of biomolecules in the embryogenesis of the tick Rhipicephalus (Boophilus) microplus

Background: The hard tick Rhipicephalus (Boophilus) microplus is an hematophagous ectoparasite that causes important economic losses in the cattle raising. The control of the parasite is usually accomplished through the use of acaricides. Even though these chemicals substances present effectiveness, their continuous use can lead to the selection of resistant parasites. When not used properly acaricides can cause environmental damages in addition to risks for animal and human health. Because of these drawbacks there are efforts to the development of alternatives control methods. The immunological control is a promissing method due to target specifi city, which increases the environmental and animal safety. The development of such approach relies on the discovery and characterization of molecules involved in the metabolism of the parasite different life stages. The embryogenesis is the stage where the metabolites of maternal origin are mobilized through catabolic and anabolic pathways necessary for the development of the embryo. The study of the substrates and enzymes involved in metabolic pathways of the embryogenesis allows the directed search to potential antigens to the development of an anti-R. microplus vaccine. Review: The embryo, during its development, passes through the stages of a sincicial blastoderm, celular blastoderm and segmentation, and both morfological changes and energy sources mobilization are related. Lipids are the major energetic source to the cellular blastoderm formation. Up to cellularization stage and after embryo segmentation, sugars are the main metabolite required. It supports that tick embryogenesis occurs with two distinct phases regarding glucose utilization by the embryo. In the initial phase, until the formation of the celular blastoderm, there is the utilization of the maternal energetic source stored in oocytes, like glycogen. After segmentation, until larval hatching, the embryo performs gluconeogenesis through non-glucidic compounds to obtain the energy input required for its metabolism. Therewith occurs the activation of the glycolytic and gluconeogenic pathways to provide glucose to the developing embryo. Due to the high levels of glucose available, it is suggested that the insulin pathway is active and be conserved in R. microplus, as previously described for other organisms. Glycogen accumulation observed throughout tick embryogenesis could be a response to an endogenous insulin-like signal. During gluconeogenesi's amino acids stored in the storage proteins of the yolk granules are enzymatically mobilized to supply the metabolic energy required for the embryo development. In this context, three peptidases involved in the degradation of yolk proteins in eggs and one peptidase in larvae were characterized, and demonstrate the importance of the use of amino acids in this phase of the tick's life. Another metabolite involved in the development of the embryo is water, whose homeostasis must be mantained in the parasitic and environmental stages of the R. microplus's life. The function of water maintenance in eggs is particularly important for embryo development. Conclusion: The study of the energetic pathways important to the metabolism of R. microplus's embryo is a promissing way for development of control methods. In this context different enzymes involved in providing energetic substrates for the embryogenesis have been indentified, characterized and can be used as targets in the immunological control of the tick.Proteinases characterized from R. microplus eggs, BYC and VTDCE, were tested as antigens to immunize bovines and provided to be immunoprotective against the parasite. Other enzymes also showed a potential to be used as targets in an anti-R.microplus vaccine.

Metabolism of biomolecules in the embryogenesis of the tick Rhipicephalus (Boophilus) microplus / Metabolismo de biomoléculas na embriogênese do carrapato Rhipicephalus (Boophilus) microplus

Background: The hard tick Rhipicephalus (Boophilus) microplus is an hematophagous ectoparasite that causes important economic losses in the cattle raising. The control of the parasite is usually accomplished through the use of acaricides. Even though these chemicals substances present effectiveness, their continuous use can lead to the selection of resistant parasites. When not used properly acaricides can cause environmental damages in addition to risks for animal and human health. Because of these drawbacks there are efforts to the development of alternatives control methods. The immunological control is a promissing method due to target specifi city, which increases the environmental and animal safety. The development of such approach relies on the discovery and characterization of molecules involved in the metabolism of the parasite different life stages. The embryogenesis is the stage where the metabolites of maternal origin are mobilized through catabolic and anabolic pathways necessary for the development of the embryo. The study of the substrates and enzymes involved in metabolic pathways of the embryogenesis allows the directed search to potential antigens to the development of an anti-R. microplus vaccine.Review: The embryo, during its development, passes through the stages of a sincicial blastoderm, celular blastoderm and segmentation, and both morfological changes a

Background: The hard tick Rhipicephalus (Boophilus) microplus is an hematophagous ectoparasite that causes important economic losses in the cattle raising. The control of the parasite is usually accomplished through the use of acaricides. Even though these chemicals substances present effectiveness, their continuous use can lead to the selection of resistant parasites. When not used properly acaricides can cause environmental damages in addition to risks for animal and human health. Because of these drawbacks there are efforts to the development of alternatives control methods. The immunological control is a promissing method due to target specifi city, which increases the environmental and animal safety. The development of such approach relies on the discovery and characterization of molecules involved in the metabolism of the parasite different life stages. The embryogenesis is the stage where the metabolites of maternal origin are mobilized through catabolic and anabolic pathways necessary for the development of the embryo. The study of the substrates and enzymes involved in metabolic pathways of the embryogenesis allows the directed search to potential antigens to the development of an anti-R. microplus vaccine.Review: The embryo, during its development, passes through the stages of a sincicial blastoderm, celular blastoderm and segmentation, and both morfological changes a

Glucose-6-phosphate Metabolic Preferential Destinations in Bovine Oviduct Cells

The oviduct is a dynamic organ which facilitates gamete function, fertilization and embryo development. This organ is covered by an epithelium containing ciliated and non-ciliated cells. Secretions of non-ciliated cells compose the oviduct fluid, which will nourish the early embryo. During the period of ovulation, the oviduct exhibits an active role, where the lumen provides an environment suitable for fertilization and the muscle layer contracts rhythmically to move the egg toward the uterus. In this study we aimed to investigate the content of fuel metabolites and enzyme activity assays related to the glycolytic metabolism in bovine oviduct cells such as Glucose-6-phosphate, Glycogen, Pyruvate, Hexokinase, Pyruvate, kinase, Phosphoenolpyruvate carboxykinase and Glucose-6-phosphate dehydrogenase.

Glucose-6-phosphate Metabolic Preferential Destinations in Bovine Oviduct Cells

The oviduct is a dynamic organ which facilitates gamete function, fertilization and embryo development. This organ is covered by an epithelium containing ciliated and non-ciliated cells. Secretions of non-ciliated cells compose the oviduct fluid, which will nourish the early embryo. During the period of ovulation, the oviduct exhibits an active role, where the lumen provides an environment suitable for fertilization and the muscle layer contracts rhythmically to move the egg toward the uterus. In this study we aimed to investigate the content of fuel metabolites and enzyme activity assays related to the glycolytic metabolism in bovine oviduct cells such as Glucose-6-phosphate, Glycogen, Pyruvate, Hexokinase, Pyruvate, kinase, Phosphoenolpyruvate carboxykinase and Glucose-6-phosphate dehydrogenase.(AU)

Metabolism of biomolecules in the embryogenesis of the tick Rhipicephalus (Boophilus) microplus / Metabolismo de biomoléculas na embriogênese do carrapato Rhipicephalus (Boophilus) microplus

Background: The hard tick Rhipicephalus (Boophilus) microplus is an hematophagous ectoparasite that causes important economic losses in the cattle raising. The control of the parasite is usually accomplished through the use of acaricides. Even though these chemicals substances present effectiveness, their continuous use can lead to the selection of resistant parasites. When not used properly acaricides can cause environmental damages in addition to risks for animal and human health. Because of these drawbacks there are efforts to the development of alternatives control methods. The immunological control is a promissing method due to target specifi city, which increases the environmental and animal safety. The development of such approach relies on the discovery and characterization of molecules involved in the metabolism of the parasite different life stages. The embryogenesis is the stage where the metabolites of maternal origin are mobilized through catabolic and anabolic pathways necessary for the development of the embryo. The study of the substrates and enzymes involved in metabolic pathways of the embryogenesis allows the directed search to potential antigens to the development of an anti-R. microplus vaccine.Review: The embryo, during its development, passes through the stages of a sincicial blastoderm, celular blastoderm and segmentation, and both morfological changes a

Background: The hard tick Rhipicephalus (Boophilus) microplus is an hematophagous ectoparasite that causes important economic losses in the cattle raising. The control of the parasite is usually accomplished through the use of acaricides. Even though these chemicals substances present effectiveness, their continuous use can lead to the selection of resistant parasites. When not used properly acaricides can cause environmental damages in addition to risks for animal and human health. Because of these drawbacks there are efforts to the development of alternatives control methods. The immunological control is a promissing method due to target specifi city, which increases the environmental and animal safety. The development of such approach relies on the discovery and characterization of molecules involved in the metabolism of the parasite different life stages. The embryogenesis is the stage where the metabolites of maternal origin are mobilized through catabolic and anabolic pathways necessary for the development of the embryo. The study of the substrates and enzymes involved in metabolic pathways of the embryogenesis allows the directed search to potential antigens to the development of an anti-R. microplus vaccine.Review: The embryo, during its development, passes through the stages of a sincicial blastoderm, celular blastoderm and segmentation, and both morfological changes a