1,721,048 research outputs found
The integral role of de novo lipogenesis in the preparation for seasonal dormancy
No full textAnimals can alter their body compositions in anticipation of dormancy to endure seasons with limited food availability. Accumulation of lipid reserves, mostly in the form of triglycerides (TAGs), is observed during the preparation for dormancy in diverse animals, including insects (diapause) and mammals (hibernation). However, the mechanisms involved in the regulation of lipid accumulation and the ecological consequences of failure to accumulate adequate lipid stores in preparation for animal dormancy remain understudied. In the broadest sense, lipid reserves can be accumulated in two ways: the animal either receives lipids directly from the environment or converts the sugars and amino acids present in food to fatty acids through de novo lipogenesis and then to TAGs. Here, we show that preparation for diapause in the Colorado potato beetle ( Leptinotarsa decemlineata ) involves orchestrated upregulation of genes involved in lipid metabolism with a transcript peak in 8- and 10-d-old diapause-destined insects. Regulation at the transcript abundance level was associated with the accumulation of substantial fat stores. Furthermore, the knockdown of de novo lipogenesis enzymes ( ACCase and FAS-1 ) prolonged the preparatory phase, while the knockdown of fatty acid transportation genes shortened the preparatory phase. Our findings suggest a model in which the insects dynamically decide when to transition from the preparation phase into diapause, depending on the progress in lipid accumulation through de novo lipogenesis.Scientific and Technological Research Council of Türkiy
What You Eat Matters: Nutrient Inputs Alter the Metabolism and Neuropeptide Expression in Egyptian Cotton Leaf Worm, Spodoptera littoralis (Lepidoptera: Noctuidae)
No full textLipids and carbohydrates are the two primary energy sources for both animals and insects. Energy homeostasis is under strict control by the neuroendocrine system, and disruption of energy homeostasis leads to the development of various disorders, such as obesity, diabetes, fatty liver syndrome, and cardiac dysfunction. One critical factor in this respect is feeding habits and diet composition. Insects are good models to study the physiological and biochemical background of the effect of diet on energy homeostasis and related disorders; however, most studies are based on a single model species, Drosophila melanogaster. In the current study, we examined the effects of four different diets, high fat (HFD), high sugar (HSD), calcium-rich (CRD), and a plant-based (PBD) on energy homeostasis in younger (third instar) and older (fifth instar) larvae of the Egyptian cotton leafworm, Spodoptera littoralis (Lepidoptera: Noctuidae) in comparison to a regular artificial bean diet. Both HSD and HFD led to weight gain, while CRD had the opposite effect and PBD had no effect in fifth instar larvae and pupae. The pattern was the same for HSD and CRD in third instar larvae while a reduction in weight was detected with HFD and PBD. Larval development was shortest with the HSD, while HFD, CRD, and PBD led to retardation compared to the control. Triglyceride (TG) levels were higher with HFD, HSD, and PBD, with larger lipid droplet sizes, while CRD led to a reduction of TG levels and lipid droplet size. Trehalose levels were highest with HSD, while CRD led to a reduction at third instar larvae, and HFD and PBD had no effect. Fifth instar larvae had similar levels of trehalose with all diets. There was no difference in the expression of the genes encoding neuropeptides SpoliAKH and SpoliILP1-2 with different diets in third instar larvae, while all three genes were expressed primarily with HSD, and SpolisNPF was primarily expressed with HFD in fifth instar larvae. In summary, different diet treatments alter the development of insects, and energy and metabolic pathways through the regulation of peptide hormones
Peritrophins are involved in the defense against Bacillus thuringiensis and nucleopolyhedrovirus formulations in Spodoptera littoralis (Lepidoptera: Noctuidae)
No full texthttp://dx.doi.org/10.13039/501100010790 Erasmus+http://dx.doi.org/10.13039/100017177 Deutscher Akademischer Austauschdienst Francehttp://dx.doi.org/10.13039/501100004189 Max-Planck-Gesellschafthttp://dx.doi.org/10.13039/501100004410 Türkiye Bilimsel ve Teknolojik Araştırma Kurum
Targeting cell death processes for insect pest control: a promising but still underexploited strategy
Full text linkCell death-related processes are fundamental to insect physiology, playing essential roles in development, immune response, and metamorphosis, thereby maintaining tissue and organism's homeostasis. Among the various cell death mechanisms, apoptosis is crucial for sculpting tissues, eliminating damaged or infected cells, and limiting pathogen replication. In parallel, autophagy serves as a self-recycling process that facilitates nutrient allocation, stress resilience, and remodeling of larval structures during development but, in specific contexts, can be associated to cell death. Beyond their physiological importance, apoptosis and autophagy have emerged as attractive targets for pest control. To this purpose two strategies can be envisaged: i) inducing cell death in key tissues using natural or synthetic compounds to compromise insects' physiology and ii) manipulating apoptotic and autophagic signaling pathways through chemical or genetic tools, such as RNAi or CRISPR, to impair development and immunity, thus reducing insect survival and fitness. Harnessing these cell death pathways offers promising new avenues for controlling insect pests and vector-borne diseases. However, further research is needed to improve the specificity, efficacy, and environmental safety of these approaches
The microRNA pathway regulates obligatory aestivation in the cabbage stem flea beetle Psylliodes chrysocephala
No full textAbstract Aestivation, or summer diapause, is a dormancy strategy that enables animals to survive hot and dry summer conditions. Despite its ecological importance, the gene regulatory mechanisms underlying aestivation remain poorly understood. MicroRNAs (miRNAs) are post-transcriptional regulators involved in various biological processes, including development. Here, we investigated the role of miRNAs in obligatory aestivation in the cabbage stem flea beetle (Psylliodes chrysocephala), a major pest of oilseed rape. Small RNA sequencing revealed that approximately 25% of miRNAs were differentially abundant during aestivation. RNA interference-mediated inhibition of the miRNA pathway, combined with proteomics, identified 116 miRNA-regulated proteins involved in metabolic and catabolic processes. Integrated transcriptome analysis suggested that 71% of these miRNA-regulated proteins were also downregulated at the mRNA level, while the remaining 29% were likely regulated primarily through translational inhibition. Degradome sequencing confirmed miRNA-mediated regulation of several transcripts and suggested exonucleolytic decay as the predominant mechanism. Disruption of the miRNA pathway impaired key aestivation traits, including metabolic suppression, changes in body composition, behavior inhibition, and heat tolerance. These findings suggest a central role for miRNAs in regulating insect dormancy, with implications for understanding climate change impacts on insect physiology and for developing novel pest control strategies
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Identification of endoplasmic reticulum proteins from the fat body of feeding adults and adults emerged from diapause in colorado potato beetle, Leptinotarsa decemlineata (Coleoptera: Chrysomelidae)
No full textPatates böceği, Leptinotarsa decemlineata (Coleoptera: Chrysomelidae), patatesin ana zararlısı olup hem larva hem ergin dönemde %100'e ulaşan ürün kayıplarına neden olabilmektedir. Patates böceğini oldukça ilginç kılan temel özelliği ise hibernasyon diyapozu döneminde 5-6 ay beslenmeden ergin dönemde toprak içerisinde çetin kış koşullarını atlatabilmesidir. Diyapoz dönemi dormant bir süreç olduğu için çok fazla enerji gerektirmemekte, fakat diyapoz sonrası için enerji temininde kritik bir aşama olarak karşımıza çıkmaktadır. Diyapozdaki başarısızlık veya tam olarak gerçekleşemeyen diyapoz böceğin ölümüne neden olabildiği için diyapoz stresli bir dönem olarak değerlendirilmektedir. Lipidler diyapoz sürecinde ana enerji kaynağı olarak kullanılmakta ve böcek yağ dokusunda (fat body) metabolize edilmektedir. Yapılan çalışmaların çoğu diyapoza bağlı olarak lipid metabolizmasına odaklanmış olsa da; lipidlerin ve proteinlerin sentezi ve modifikasyonunda yer alan endoplazmik retikulum (ER)'a spesifik proteinler üzerindeki bilgi oldukça kısıtlıdır. Mevcut tez çalışmasında, patates böceğinin diyapoz sonrası bireyleri ile ve yazın aktif olarak beslenen bireylerinin ER'sinde bulunan proteinler kantitatif proteomiks yöntemiyle belirlenmiştir. Gen ontoloji analizi kullanılarak proteinlerin tanımlaması yapılmış ve temel işlevleri tahmin edilmiştir. Buna göre gerek aktif olarak beslenen gerekse de diyapoz sonrasındaki böceklerin yağ dokusu ER'sinden toplam 3639 protein tanımlanmıştır. 108 tanesi ise diyapoz sonrası dönemde istatistiki olarak artış gösteren proteinler olarak tanımlanmıştır. Buna göre ER'nin yapısındaki lipid metabolizması ve kalsiyum yolağı ile ilişkili proteinlerin diyapoz ve diyapozdan çıkış üzerine etki eden major proteinler içerisinde yer aldığı tespit edilmiştir.Potato beetle, Leptinotarsadecemlineata (Coleoptera: Chrysomelidae), is the major pest and causes significant damage by eating the leaves of the potato foliage in both the larva and adult stages, and it can cause product losses up to 100%. The main feature of the potato beetle is the ability to diapause which makes it is very interesting. Potato beetle can survive the harsh winter conditions in the soil in the adult period without feeding during the hibernation for 5-6 months. Diapause is a physiologically dormant stage to overcome freezing temperatures and long‐term food deprivation in winter. Failure in the diapause program or incomplete diapause might lead to death. Lipids are the main energy sources to complete diapause successfully and lipids are metabolized in the fat body. Although several studies have focused on the lipid metabolism in relation to diapause the knowledge on the specific protein residents of the endoplasmic reticulum (ER) which is involved in the synthesis and modification of lipids and key proteins is poorly understood. We conducted the quantitative proteomics method of the proteins in the ER of the post-diapausing of the potato beetle and the actively feeding. We determined the basic function of the proteins using Gene Ontology analysis. Based on proteome analysis, A total of 3639 proteins have been identified both actively feeding insects post-diapausing beetles from the fat body of ER. Therefore, 108 proteins were significantly upregulated exposed to post-diapausing beetles when compared to the actively feeding beetles. analysis, A total of 3639 proteins have been identified both actively feeding insects post-diapausing beetles from the fat body of ER. Therefore, 108 proteins were significantly upregulated exposed to post-diapausing beetles when compared to the actively feeding beetles
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