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1.
Semin Cell Dev Biol ; 138: 83-93, 2023 03 30.
Artigo em Inglês | MEDLINE | ID: mdl-35317962

RESUMO

Developing embryos are metabolically active, open systems that constantly exchange matter and energy with their environment. They function out of thermodynamic equilibrium and continuously use metabolic pathways to obtain energy from maternal nutrients, in order to fulfill the energetic requirements of growth and development. While an increasing number of studies highlight the role of metabolism in different developmental contexts, the physicochemical basis of embryogenesis, or how cellular processes use energy and matter to act together and transform a zygote into an adult organism, remains unknown. As we obtain a better understanding of metabolism, and benefit from current technology development, it is a promising time to revisit the energetic cost of development and how energetic principles may govern embryogenesis. Here, we review recent advances in methodology to measure and infer energetic parameters in developing embryos. We highlight a potential common pattern in embryonic energy expenditure and metabolic strategy across animal embryogenesis, and discuss challenges and open questions in developmental energetics.


Assuntos
Desenvolvimento Embrionário , Metabolismo Energético , Animais
2.
Curr Biol ; 32(8): 1788-1797.e5, 2022 04 25.
Artigo em Inglês | MEDLINE | ID: mdl-35316653

RESUMO

Insulin/insulin-like growth factor (IGF) signaling (IIS) controls many aspects of development and physiology. In Drosophila, a conserved family of insulin-like peptides called Dilps is produced by brain neurosecretory cells, and it regulates organismal growth and developmental timing. To accomplish these systemic functions, the Dilps are secreted into the general circulation, and they signal to peripheral tissues in an endocrine fashion. Here, we describe the local uptake and storage of Dilps in the corpora cardiaca (CC), an endocrine organ composed of alpha cell homologs known to produce the glucagon-like adipokinetic hormone (AKH). We show that Dilp uptake by the CC relies on the expression of an IGF-binding protein called ImpL2. Following their uptake, immunogold staining demonstrates that Dilps are co-packaged with AKH in dense-core vesicles for secretion. In response to nutrient shortage, this specific Dilp reservoir is released and activates IIS in a paracrine manner in the prothoracic gland. This stimulates the production of the steroid hormone ecdysone and initiates entry into pupal development. We therefore uncover a sparing mechanism whereby insulin stores in CC serve to locally activate IIS and the production of ecdysone in the PG, accelerating developmental progression in adverse food conditions.


Assuntos
Proteínas de Drosophila , Somatomedinas , Animais , Drosophila/fisiologia , Proteínas de Drosophila/genética , Proteínas de Drosophila/metabolismo , Drosophila melanogaster/metabolismo , Ecdisona/metabolismo , Insulina/metabolismo , Proteínas de Ligação a Fator de Crescimento Semelhante a Insulina/metabolismo , Larva/metabolismo , Nutrientes , Somatomedinas/metabolismo
3.
Nat Cell Biol ; 21(9): 1053-1054, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-31439910
4.
Nature ; 572(7768): 178, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-31388165
5.
Proc Natl Acad Sci U S A ; 114(50): 13218-13223, 2017 Dec 12.
Artigo em Inglês | MEDLINE | ID: mdl-29180408

RESUMO

With more than 80% of flowering plant species specialized for animal pollination, understanding how wild pollinators utilize resources across environments can encourage efficient planting and maintenance strategies to maximize pollination and establish resilience in the face of environmental change. A fundamental question is how generalist pollinators recognize "flower objects" in vastly different ecologies and environments. On one hand, pollinators could employ a specific set of floral cues regardless of environment. Alternatively, wild pollinators could recognize an exclusive signature of cues unique to each environment or flower species. Hoverflies, which are found across the globe, are one of the most ecologically important alternative pollinators after bees and bumblebees. Here, we have exploited their cosmopolitan status to understand how wild pollinator preferences change across different continents. Without employing any a priori assumptions concerning the floral cues, we measured, predicted, and finally artificially recreated multimodal cues from individual flowers visited by hoverflies in three different environments (hemiboreal, alpine, and tropical) using a field-based methodology. We found that although "flower signatures" were unique for each environment, some multimodal lures were ubiquitously attractive, despite not carrying any reward, or resembling real flowers. While it was unexpected that cue combinations found in real flowers were not necessary, the robustness of our lures across insect species and ecologies could reflect a general strategy of resource identification for generalist pollinators. Our results provide insights into how cosmopolitan pollinators such as hoverflies identify flowers and offer specific ecologically based cues and strategies for attracting pollinators across diverse environments.


Assuntos
Dípteros/fisiologia , Meio Ambiente , Flores/fisiologia , Modelos Biológicos , Polinização , Animais , Sinais (Psicologia) , Rhododendron/fisiologia
6.
Development ; 144(23): 4406-4421, 2017 12 01.
Artigo em Inglês | MEDLINE | ID: mdl-29038308

RESUMO

Quantitative analysis of the dynamic cellular mechanisms shaping the Drosophila wing during its larval growth phase has been limited, impeding our ability to understand how morphogen patterns regulate tissue shape. Such analysis requires explants to be imaged under conditions that maintain both growth and patterning, as well as methods to quantify how much cellular behaviors change tissue shape. Here, we demonstrate a key requirement for the steroid hormone 20-hydroxyecdysone (20E) in the maintenance of numerous patterning systems in vivo and in explant culture. We find that low concentrations of 20E support prolonged proliferation in explanted wing discs in the absence of insulin, incidentally providing novel insight into the hormonal regulation of imaginal growth. We use 20E-containing media to observe growth directly and to apply recently developed methods for quantitatively decomposing tissue shape changes into cellular contributions. We discover that whereas cell divisions drive tissue expansion along one axis, their contribution to expansion along the orthogonal axis is cancelled by cell rearrangements and cell shape changes. This finding raises the possibility that anisotropic mechanical constraints contribute to growth orientation in the wing disc.


Assuntos
Drosophila melanogaster/citologia , Drosophila melanogaster/crescimento & desenvolvimento , Asas de Animais/citologia , Asas de Animais/crescimento & desenvolvimento , Animais , Animais Geneticamente Modificados , Padronização Corporal/efeitos dos fármacos , Padronização Corporal/genética , Padronização Corporal/fisiologia , Proliferação de Células/efeitos dos fármacos , Proliferação de Células/fisiologia , Drosophila melanogaster/genética , Ecdisterona/farmacologia , Ecdisterona/fisiologia , Perfilação da Expressão Gênica , Regulação da Expressão Gênica no Desenvolvimento/efeitos dos fármacos , Genes de Insetos , Discos Imaginais/citologia , Discos Imaginais/efeitos dos fármacos , Discos Imaginais/crescimento & desenvolvimento , Insulina/farmacologia , Insulina/fisiologia , Morfogênese/efeitos dos fármacos , Morfogênese/genética , Morfogênese/fisiologia , Transdução de Sinais , Transcrição Gênica/efeitos dos fármacos , Asas de Animais/efeitos dos fármacos
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