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1.
Bull Entomol Res ; 114(2): 210-229, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38444234

RESUMO

The Asian citrus psyllid, Diaphorina citri Kuwayama (Hemiptera: Psyllidae), is the key vector insect transmitting the Candidatus Liberibacter asiaticus (CLas) bacterium that causes the devastating citrus greening disease (Huanglongbing, HLB) worldwide. The D. citri salivary glands (SG) exhibit an important barrier against the transmission of HLB pathogen. However, knowledge on the molecular mechanism of SG defence against CLas infection is still limited. In the present study, we compared the SG transcriptomic response of CLas-free and CLas-infected D. citri using an illumine paired-end RNA sequencing. In total of 861 differentially expressed genes (DEGs) in the SG upon CLas infection, including 202 upregulated DEGs and 659 downregulated DEGs were identified. Functional annotation analysis showed that most of the DEGs were associated with cellular processes, metabolic processes, and the immune response. Gene ontology and Kyoto Encyclopaedia of Genes and Genomes enrichment analyses revealed that these DEGs were enriched in pathways involving carbohydrate metabolism, amino acid metabolism, the immune system, the digestive system, the lysosome, and endocytosis. A total of 16 DEGs were randomly selected to further validate the accuracy of RNA-Seq dataset by reverse-transcription quantitative polymerase chain reaction. This study provides substantial transcriptomic information regarding the SG of D. citri in response to CLas infection, which may shed light on the molecular interaction between D. citri and CLas, and provides new ideas for the prevention and control of citrus psyllid.


Assuntos
Hemípteros , Glândulas Salivares , Transcriptoma , Animais , Hemípteros/microbiologia , Hemípteros/genética , Glândulas Salivares/microbiologia , Glândulas Salivares/metabolismo , Doenças das Plantas/microbiologia , Citrus/microbiologia , Liberibacter
2.
Pest Manag Sci ; 80(2): 648-660, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-37756442

RESUMO

BACKGROUND: Insulin signalling pathways play crucial roles in regulating growth and development in insects, but their effects on the growth and development of Arachnids, such as spiders, have rarely been studied. As a valuable pest natural enemy in agricultural fields, the molecular mechanisms of insulin signalling pathway-mediated growth and development of the wolf spider, Pardosa pseudoannulata, are of particular interest. RESULTS: In this study, we identified and characterized six insulin signalling pathway genes - InR, InR2, IRS1, PI3K1, PI3K2, and PDK - in Pardosa pseudoannulata. Real-time quantitative polymerase chain reaction results were used to analyse the relative expression levels of the six genes in different developmental instars and tissues, and in response to starvation treatment. In addition, the function of the insulin receptor substrate (IRS1) gene was investigated using RNA interference technology, which found that IRS1 significantly influenced nutrient content, developmental duration, body weight, and gonad development. CONCLUSION: This study revealed the roles of six key insulin signalling pathway genes in Pardosa pseudoannulata, and in particular the importance of the IRS1 gene in regulating growth and development in the spider. The results lay the foundation for further research on the internal regulation mechanisms of growth and development in Araneae species, and also provide a reference for the artificial breeding of spiders. © 2023 Society of Chemical Industry.


Assuntos
Animais Peçonhentos , Insulinas , Aranhas , Animais , Interferência de RNA , Receptor de Insulina/genética , Receptor de Insulina/metabolismo , Receptor de Insulina/farmacologia , Aranhas/genética , Crescimento e Desenvolvimento , Insulinas/genética , Insulinas/metabolismo , Insulinas/farmacologia
3.
Phys Rev Lett ; 131(16): 161904, 2023 Oct 20.
Artigo em Inglês | MEDLINE | ID: mdl-37925731

RESUMO

The failure of observing the e^{+}e^{-}→J/ψJ/ψ events at B factories to date is often attributed to the significant negative order-α_{s} correction. In this work we compute the O(α_{s}^{2}) correction to this process for the first time. The magnitude of the next-to-next-to-leading order (NNLO) perturbative correction is substantially negative so that the standard nonrelativistic QCD prediction would suffer from an unphysical, negative cross section. This dilemma may be traced in the fact that the bulk contribution of the fixed-order radiative corrections stems from the perturbative corrections to the J/ψ decay constant. We thus implement an improved nonrelativistic QCD factorization framework, by decomposing the amplitude into the photon-fragmentation piece and the nonfragmentation piece. With the measured J/ψ decay constant as input, which amounts to resumming a specific class of radiative and relativistic corrections to all orders, the fragmentation-induced production rate can be predicted accurately and serves a benchmark prediction. The nonfragmentation type of the amplitude is then computed through NNLO in α_{s} and at lowest order in velocity. Both the O(α_{s}) and O(α_{s}^{2}) corrections in the interference term become positive and exhibit a decent convergence behavior. Our finest prediction is σ(e^{+}e^{-}→J/ψJ/ψ)=2.13_{-0.06}^{+0.30} fb at sqrt[s]=10.58 GeV. With the projected integrated luminosity of 50 ab^{-1}, the prospect to observe this exclusive process at Belle 2 experiment appears to be bright.

4.
Brain Sci ; 13(8)2023 Jul 25.
Artigo em Inglês | MEDLINE | ID: mdl-37626481

RESUMO

BACKGROUND: Parkinson's disease (PD) is seriously threatening the health and life quality of the elderly, who have a high incidence and high disability rate. Resveratrol (RES) was reported to play a protective role in PD. However, the functions and potential mechanism of RES in PD remain unclear, which need to be further explored. METHODS: Human neuroblastoma cells (SH-SY5Y and SK-N-SH) were subjected to 1-Methyl-4-phenylpyridium (MPP+) induction to construct a cell model of PD. Cell viability was evaluated using CCK-8. The gene expression was evaluated using qRT-PCR and western blot. Luciferase activity assay and RIP were performed to validate interactions among SNHG1, miR-128-3p and SNCA. RESULTS: Our results exhibited that RES reduced SNHG1 and SNCA expression but elevated miR-128-3p expression in human neuroblastoma cells upon MPP+ induction. Functionally, RES resulted in the promotion of cell autophagy in MPP+-induced human neuroblastoma cells, while these influences were abolished by SNHG1 overexpression. Mechanistically, SNHG1 could indirectly elevate SNCA expression via sponging miR-128-3p. Moreover, SNCA overexpression reversed SNHG1 silencing-induced cell autophagy in MPP+-induced human neuroblastoma cells upon RES pre-incubation. CONCLUSIONS: RES prevented MPP+-induced repression of cell autophagy through inhibiting the SNHG1/miR-128-3p/SNCA axis, suggesting that RES might play a preventive effect on PD progression.

5.
Curr Osteoporos Rep ; 21(4): 401-413, 2023 08.
Artigo em Inglês | MEDLINE | ID: mdl-37273086

RESUMO

PURPOSE OF REVIEW: The goal of this review is to summarize recent findings related to modifications in osteocyte lacunar and canalicular morphology due to physiological and pathological conditions. In addition, this review aims to outline how these modifications may influence the local mechanical environment of osteocytes and their mechanosensitivity. RECENT FINDINGS: Reduction in lacunar density with age and increasing lacunar size with lactation are confirmed in multiple studies in human and murine bone. There is also evidence of a reduction in canalicular density, length, and branching, as well as increasing sphericity and smaller lacunae with aging and disease. However, while some studies have found modifications in lacunar density, size, shape, and orientation, as well as canalicular density, length, and size due to specific physiological and pathological conditions, others have not observed any differences. Recent finite element models provide insights into how observed modifications in the lacunar-canalicular network (lacunar and canalicular density) and lacunar-canalicular morphology (lacunar area/volume, shape, and orientation as well as canalicular diameter and length) may influence the fluid flow and local strains around the lacunar-canalicular network and modify the local mechanical environment of osteocytes. Modifications in the lacunar-canalicular network morphology may lead to significant changes in the strains received by osteocytes and may influence bone's response to mechanical stimulation as osteocytes are the primary mechanosensing bone cells. Further experimental and computational studies will continue to improve our understanding of the relationship between lacunar-canalicular network morphology and osteocyte mechanosensitivity.


Assuntos
Osso e Ossos , Osteócitos , Feminino , Humanos , Camundongos , Animais , Osteócitos/fisiologia , Envelhecimento , Lactação
6.
Ecotoxicol Environ Saf ; 251: 114519, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36634478

RESUMO

Blue light with a wavelength of 400-470 nm is the composition of the visible light. However, in recent years, blue light contributed the most significance to light pollution due to the artificial light at night. Previously, we have demonstrated that the Asian citrus psyllid (ACP), Diaphorina citri, an important pest in citrus production, has significant positive phototaxis with a light-emitting diode light of 400 nm. In this study, ACP with positive phototactic behavior to 400 nm light (PH) and non-phototactic behavior to 400 nm light (NP) were collected, individually. Transcriptome dynamics of head tissues of PH and NP groups were captured by using RNA-sequencing technology, respectively. Forty-three to 46 million clean reads with high-quality values were obtained, and 1773 differential expressed genes (DEGs) were detected. Compared with the NP group, there were 841 up-regulated DEGs and 932 down-regulated DEGs in the PH group. Eight pathways were significantly enriched in the PH group in the KEGG database, while 43 up-regulated pathways and 25 down-regulated pathways were significantly enriched in the PH group in the GO database. The DGE approach was reliable validated by real time quantitative PCR. Results indicated that the blue light acted as an abiotic stress causing physiological and biochemical responses such as oxidative stress, protein denaturation, inflammation and tumor development in ACPs. Additionally, the light was absorbed by photoreceptors of ACPs, and converted into electrical signal to regulate neuromodulation. This study provides basic information for understanding the molecular mechanisms of ACP in response to blue light and provides a reference for further studies to elucidate phototactic behavior.


Assuntos
Citrus , Hemípteros , Animais , Fototaxia , Hemípteros/genética , Hemípteros/metabolismo , Transcriptoma , Luz , Citrus/genética , Encéfalo
7.
J Biomech Eng ; 145(6)2023 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-36629002

RESUMO

Physiological and pathological processes such as aging, diseases, treatments, and lactation can alter lacunar-canalicular network (LCN) morphology and perilacunar region properties. These modifications can impact the mechanical environment of osteocytes which in turn can influence osteocyte mechanosensitivity and the remodeling process. In this study, we aim to evaluate how the modifications in the canalicular morphology, lacunar density, and the perilacunar region properties influence the local mechanical environment of LCN and the apparent bone properties using three-dimensional finite element (FE) modeling. The simulation results showed that a 50% reduction in perilacunar elastic modulus led to about 7% decrease in apparent elastic modulus of the bone. The increase in canalicular density, length, and diameter did not influence the strain amplification in the models but they increased the amount of highly strained bone around LCN. Change in lacunar density did not influence the strain amplification and the amount of highly strained regions on LCN surfaces. Reduction in perilacunar elastic modulus increased both the strain amplification and the volume of highly strained tissue around and on the surface of LCN. The FE models of LCN in this study can be utilized to quantify the influence of modifications in canalicular morphology, lacunar density, and perilacunar region properties on the apparent bone properties and the local mechanical environment of LCN. Although this is a numerical study with idealized models, it provides important information on how mechanical environment of osteocytes is influenced by the modifications in LCN morphology and perilacunar region properties due to physiological and pathological processes.


Assuntos
Osso e Ossos , Osteócitos , Feminino , Humanos , Análise de Elementos Finitos , Simulação por Computador
8.
Insect Sci ; 30(4): 1022-1034, 2023 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-36346663

RESUMO

The Asian citrus psyllid, Diaphorina citri Kuwayama, is among the most important pests of citrus. It is the main vector of the Huanglongbing (HLB) pathogen Candidatus Liberibacter asiaticus (CLas), which causes severe losses in citrus crops. Control of D. citri is therefore of paramount importance to reduce the spread of HLB. In this regard, using RNA interference (RNAi) to silence target genes is a useful strategy to control psyllids. In this study, using RNAi, we examined the biological functions of the V-ATPase subunit E (V-ATP-E) gene of D. citri, including its effect on acquisition of CLas. The amino acid sequence of V-ATP-E from D. citri had high homology with proteins from other insects. V-ATP-E was expressed at all D. citri life stages analyzed, and the expression level in mature adults was higher than that of teneral adults. Silencing of V-ATP-E resulted in a significant increase in mortality, reduced body weight, and induced cell apoptosis of the D. citri midgut. The reduced expression of V-ATP-E was indicated to inhibit CLas passing through the midgut and into the hemolymph, leading to a majority of CLas being confined to the midgut. In addition, double-stranded RNA of D. citri V-ATP-E was safe to non-target parasitic wasps. These results suggest that V-ATP-E is an effective RNAi target that can be used in D. citri control to block CLas infection.


Assuntos
Citrus , Hemípteros , Rhizobiaceae , Animais , Hemípteros/genética , Hemípteros/metabolismo , Trifosfato de Adenosina/metabolismo , Adenosina Trifosfatases/metabolismo , Citrus/genética , Doenças das Plantas
9.
Insect Sci ; 30(1): 95-108, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-35510515

RESUMO

Diaphorina citri is an important vector of Citrus Huanglongbing (HLB) disease. After feeding on young host plant shoots, the population of D. citri can increase significantly. Females also only lay eggs on young shoots. However, there are few studies on the mechanism of this phenomenon. Exogenous nutrient signals can affect the insulin signaling system of D. citri after feeding on young shoots. In this study, the expression of upstream factors DcILP1, DcILP2, and DcIR in the insulin signaling system of D. citri was upregulated after feeding on young shoots. After being silenced by RNA interference technology, the results showed that the number of oviposited eggs of D. citri was significantly decreased and the ovarian development was inhibited with severe vacuolation. In addition, detection using quantitative reverse transcription-polymerase chain reaction showed that the upstream regulatory gene DcRheb of the target of rapamycin (TOR) pathway and the downstream reproduction-related DcVg gene were also significantly downregulated. These results suggest that feeding upon young shoots may upregulate the expression levels of upstream factors DcILP1, DcILP2, and DcIR in the insulin signaling system. The signal will be through upregulating the expression of DcRheb, an upstream gene of the TOR signaling pathway. This in turn influences yolk metabolism, which eventually causes the ovaries of female D. citri to mature and therefore initiate oviposition behavior.


Assuntos
Citrus , Hemípteros , Feminino , Animais , Insulina , Oviposição , Peptídeos , Interferência de RNA , Hemípteros/genética , Doenças das Plantas
10.
Front Physiol ; 13: 978534, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36225297

RESUMO

The olfactory system is an important component of insect behavior and is vital for survival and reproduction. However, the genomic characterization and molecular basis of the olfactory response of Megalurothrips usitatus remain relatively unknown. RNA sequencing-built developmental transcriptomes of nymphs, pupae, and adult M. usitatus were examined in order to establish the sequence-based background of M. usitatus olfactory responses. A total of 56,669 unigenes were annotated using GO, NR, Pfam, eggNOG, SwissProt, and KEGG. The number of differentially expressed genes between pupae and nymphs, males and nymphs, and females and nymphs were 10,498, 9,235, and 10,964, respectively. One odorant-binding protein (MusiOBP1) and one chemosensory protein (MusiCSP1) were selected from the transcriptome, and their full-length sequences were obtained using RACE PCR. The relative expression of MusiOBP1 was the highest in primordial females, whereas the relative expression of MusiCSP1 was the highest in primordial pupae. The strongest binding ability to the odor-binding protein MusiOBP1 was observed for ß-citronellol. 3-Hydroxy-2-methyl-4-pyrone showed the strongest binding affinity to MusiCSP1. Our analysis suggests that MusiOBP1 and MusiCSP1 may play significant roles in mediating M. usitatus host recognition. This research will improve our knowledge of odorant-binding proteins and chemosensory proteins, which will in turn improve our understanding of insect olfactory systems.

11.
Ecotoxicol Environ Saf ; 241: 113852, 2022 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-36068768

RESUMO

Contamination of agro-ecosystems with heavy metals can affect the development and reproduction of insect natural enemies. This study reports a detailed Tandem Mass Tag based quantitative proteomic analysis of underlying mechanisms responsible for stress response of Cryptolaemus montrouzieri against heavy metals (cadmium (Cd) and lead (Pb)) transported across a multi-trophic food chain. A total of 6639 proteins were detected under Cd as well as Pb stress. In Pb versus the control cluster, 69 proteins (28 up-regulated and 41 down-regulated) were differentially expressed whereas 268 proteins were differentially expressed under Cd versus the control cluster, having 198 proteins up-regulated and 70 down-regulated proteins. The analysis of differentially expressed proteins showed that 27 proteins overlapped in both clusters representing the core proteome to Pb and Cd stress. The bioinformatics analysis demonstrated that these proteins were mapped to 57 and 99 pathways in Pb versus control and Cd versus control clusters, respectively. The functional classification by COG, GO and KEGG databases showed significant changes in protein expression by C. montrouzieri under Pb and Cd stress. The heavy metal stress (Pb and Cd) induced significant changes in expression of proteins like hexokinase (HK), succinyl-CoA, trypsin like proteins, cysteine proteases, cell division cycle proteins, and yellow gene proteins. The results provide detailed information on the protein expression levels of C. montrouzieri and will serve as basic information for future proteomic studies on heavy metal responses of insect predators within a multi-trophic food chain.


Assuntos
Besouros , Metais Pesados , Animais , Cádmio/metabolismo , Besouros/fisiologia , Ecossistema , Cadeia Alimentar , Insetos , Chumbo/metabolismo , Chumbo/toxicidade , Metais Pesados/metabolismo , Metais Pesados/toxicidade , Proteômica
12.
J Mech Behav Biomed Mater ; 135: 105433, 2022 11.
Artigo em Inglês | MEDLINE | ID: mdl-36099785

RESUMO

Previous studies have demonstrated that osteocyte lacunar morphology and perilacunar bone tissue properties undergo alterations due to physiological and pathological processes such as aging, lactation, diseases, and treatments. However, the influence of these alterations on the apparent mechanical properties of the bone and the local mechanical environment of osteocyte lacunae has not been evaluated in detail. The goal of this study is to quantify the influence of osteocyte lacunar morphology and perilacunar tissue properties on local mechanical environment around lacunae and the apparent mechanical properties of the bone using three-dimensional FE models of lacunae networks with varying lacunar morphology and perilacunar properties based on previously reported experimental data. To attain this goal, a parametric study using models with different lacunar/perilacunar properties, including lacunar density (Lc.D), orientation (Lc.Φ), volume (Lc.V), and equancy (Lc.Eq), as well as perilacunar modulus (Pl.E), and size (Pl.S) was carried out. In addition, a specific case study using models derived from aged and young bone specimens was performed. Our results showed that the highly strained tissue around lacunae increased linearly with increasing Lc.D and Lc.V, reduced exponentially with decreasing angle of major axis of lacunae from the loading direction and with increasing Pl.E, and increased exponentially with increasing Pl.S. The change in apparent elastic modulus with modifications in lacunar morphology was very small whereas the change in perilacunar modulus had a more substantial influence on the apparent elastic modulus. Lacunar strain amplification was reduced by increasing Lc.Φ, and Pl.E and increased with increasing Lc.V within the range of 1.5 and 2.3. No significant difference was seen in the apparent elastic modulus of models derived from young and aged bone models. However, young bone showed substantially larger amount of highly strained tissue around lacunae compared to the aged bone. This difference was amplified when the perilacunar tissue property modifications were incorporated in the models. In summary, the results indicate that modifications in the osteocyte lacunar morphology and perilacunar tissue properties can significantly alter local tissue deformation around lacunae which may impact osteocyte mechanosensitivity.


Assuntos
Osso e Ossos , Osteócitos , Idoso , Módulo de Elasticidade , Feminino , Análise de Elementos Finitos , Humanos , Osteócitos/patologia
13.
Phys Rev Lett ; 129(11): 112002, 2022 Sep 09.
Artigo em Inglês | MEDLINE | ID: mdl-36154401

RESUMO

In this Letter, we study the exclusive decay of ϒ into J/ψ in association with η_{c} (χ_{c0,1,2}). The decay widths for different helicity configurations are evaluated up to QCD next-to-leading order within the nonrelativistic QCD framework. We find that the QCD corrections notably mitigate the renormalization scale dependence of the decay widths for all the processes. The branching fraction of ϒ→J/ψ+χ_{c1} is obtained as 3.73_{-2.06-1.19}^{+5.10+0.10}×10^{-6}, which agrees well with the Belle measurement, i.e., Br(ϒ→J/ψ+χ_{c1})=(3.90±1.21±0.23)×10^{-6}. For the other processes, our results of the branching fractions are compatible with the upper limits given by the Belle experiments, except for ϒ(2S)→J/ψ+χ_{c1}, where some tension exists between theory and experiment. Having the polarized decay widths, we study the J/ψ polarization, which turns out to be independent of any nonperturbative parameters. Further, according to our calculation, it is promising to measure all the processes at Super B factory thanks to the high luminosity.

14.
J Mater Chem B ; 10(36): 6928-6938, 2022 09 21.
Artigo em Inglês | MEDLINE | ID: mdl-35983886

RESUMO

Point-of-care testing (POCT) of tumor markers, such as alpha-fetoprotein (AFP) and carcinoembryonic antigen (CEA), can be used for the early diagnosis of cancer. In this paper, a highly sensitive electrochemical immuno-biochip based on a porous three-dimensional graphene aerogel (3D-GA) is presented to detect multiple tumor biomarkers and exosomes. The 3D-GA was prepared via in situ chemical reduction of graphene oxide with L-ascorbic acid and then dehydration by freeze-drying. The obtained 3D-GA exhibits a large specific surface area of 125.3 m2 g-1 due to its intrinsic 3D porous architecture. After chemical activation and modification of the 3D-GA, the prepared microfluidic biochip can be used for detecting various tumor markers in liquid samples via electrochemical impedance spectroscopy (EIS). The electrochemical platform with only 5 µL sample achieved a broad detection range of 1.0 × 10-8-1.0 × 10-5 and 1.0 × 10-8-5.0 × 10-4 mg mL-1 for AFP and CEA, respectively, and a low limit of detection (LOD) of 7.9 and 6.2 pg mL-1 for AFP and CEA respectively, which was much better than the outcomes of many other reports. Moreover, the biochip determined the tumor cell-derived exosomes with a low LOD of 10 particles per µL in the PBS solution and an average recovery rate of ∼90% in the diluted serum.


Assuntos
Técnicas Biossensoriais , Grafite , Ácido Ascórbico , Biomarcadores Tumorais/química , Técnicas Biossensoriais/métodos , Antígeno Carcinoembrionário , Técnicas Eletroquímicas/métodos , Grafite/química , Testes Imediatos , alfa-Fetoproteínas
15.
Mitochondrial DNA B Resour ; 7(4): 575-576, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35386625

RESUMO

The complete mitochondrial genome (mitogenome) of Coptodryas elegans was determined, which represents the first sequenced mitogenome from Coptodryas. This mitogenome is 15,959 bp in size and comprises 36 typical coding genes and a control region, the tRNAIle was not detected in this mitogenome, as observed in other species of Curculionidae. The monophyly of the family Scolytinae and the sister relationship between C. elegans and Cyclorhipidion bodoanus is supported by maximum likelihood analysis derived from the protein-coding gene sequences.

16.
J Mech Behav Biomed Mater ; 125: 104943, 2022 01.
Artigo em Inglês | MEDLINE | ID: mdl-34736032

RESUMO

Despite the extensive studies on biological function of osteocytes, there are limited studies that evaluated the structural role of osteocyte lacunae on local mechanical properties of the bone matrix. As a result, the goal of this study was to elucidate the independent contribution of osteocyte lacunae structure on mechanical properties and fracture behavior of the bone matrix uncoupled from its biological effects and bone tissue composition variation. This study combined cohesive finite element modeling with experimental data from a lactation rat model to evaluate the influence of osteocyte lacunar area porosity, density, size, axis ratio, and orientation on the elastic modulus, ultimate strength, and ultimate strain of the bone matrix as well as on local crack formation and propagation. It also performed a parametric study to isolate the influence of a single osteocyte lacunae structural property on the mechanical properties of the bone matrix. The experimental measurements demonstrated statistically significant differences in lacunar size between ovariectomized rats with lactation history and virgin groups (both ovariectomized and intact) and in axis ratio between rats with lactation history and virgins. There were no differences in mechanical properties between virgin and lactation groups as determined by the finite element simulations. However, there were statistically significant linear relationships between the physiological range of osteocyte lacunar area porosity, density, size, and orientation and the elastic modulus and ultimate strength of the bone matrix in virgin and lactation rats. The parametric study also revealed similar but stronger relationships between elastic modulus and ultimate strength and lacunar density, size, and orientation. The simulations also demonstrated that the osteocyte lacunae guided the crack propagation through local stress concentrations. In summary, this study enhanced the limited knowledge on the structural role of osteocyte lacunae on local mechanical properties of the bone matrix. These data are important in gaining a better understanding of the mechanical implications of the local modifications due to osteocytes in the bone matrix.


Assuntos
Matriz Óssea , Osteócitos , Animais , Módulo de Elasticidade , Feminino , Análise de Elementos Finitos , Porosidade , Ratos
17.
Insect Biochem Mol Biol ; 140: 103681, 2022 01.
Artigo em Inglês | MEDLINE | ID: mdl-34800642

RESUMO

Oxygen (O2) plays an essential role in aerobic organisms including terrestrial insects. Under hypoxic stress, the cowpea bruchid (Callosobruchus maculatus) ceases feeding and growth. However, larvae, particularly 4th instar larvae exhibit very high tolerance to hypoxia and can recover normal growth once brought to normoxia. To better understand the molecular mechanism that enables insects to cope with low O2 stress, we performed RNA-seq to distinguish hypoxia-responsive genes in midguts and subsequently identified potential common cis-elements in promoters of hypoxia-induced and -repressed genes, respectively. Selected elements were subjected to gel-shift and transient transfection assays to confirm their cis-regulatory function. Of these putative common cis-elements, AREB6 appeared to regulate the expression of CmLPCAT and CmScylla, two hypoxia-induced genes. CmZFH, the putative AREB6-binding protein, was hypoxia-inducible. Transient expression of CmZFH in Drosophila S2 cells activated CmLPCAT and CmScylla, and their induction was likely through interaction of CmZFH with AREB6. Binding to AREB6 was further confirmed by bacterially expressed CmZFH recombinant protein. Deletion analyses indicated that the N-terminal zinc-finger cluster of CmZFH was the key AREB6-binding domain. Through in silico and experimental exploration, we discovered novel transcriptional regulatory components associated with gene expression dynamics under hypoxia that facilitated insect survival.


Assuntos
Besouros , Hipóxia/genética , Animais , Besouros/genética , Besouros/fisiologia , Genes de Insetos , Insetos , Larva/genética , Larva/fisiologia , Oxigênio/metabolismo , Regiões Promotoras Genéticas , Ligação Proteica , Dedos de Zinco/genética
18.
Front Physiol ; 12: 777908, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34955890

RESUMO

The Asian citrus psyllid (ACP) Diaphorina citri is the main vector of the pathogen Candidatus Liberibacter asiaticus (CLas), which is the causal agent of citrus Huanglongbing disease. Feeding by both ACP nymphs and adults on host plants allows them to obtain nutrition. Therefore, the nutritional content within the plant phloem is of much importance for the development and reproduction of ACP. The infection by pathogenic microbiomes may affect the amino acid contents of their host plants and then indirectly affect the biology of sap-feeding insects. In this study, we investigated the amino acid contents and their proportions in both CLas-infected and CLas-free citrus plants, ACP adults, and also in honeydew produced by ACP nymphs. Results showed that infection by CLas had a large impact on the amino acid species and proportion in all the tested target plants, ACP adults, and in the honeydew of ACP nymphs. The content of total amino acids in CLas-infected citrus was much higher than that of CLas-free citrus. However, CLas infection significantly reduced the proportion of essential amino acids (EAAs) in these plants. When feeding on CLas-infected citrus plants, ACP adults absorbed less total amino acids than those adults feeding on healthy plants, but the proportion of EAAs was significantly higher when they fed on CLas-infected citrus plants. The proportion of EAAs also significantly increased in the honeydew secreted by ACP nymphs that fed on CLas-infected citrus plants. However, EAA detection in the honeydew of ACP nymphs indicated that the utilization rate of EAAs by CLas positive ACP nymphs was reduced. Our study has revealed that CLas infection significantly affects the contents, proportion, and utilization efficiency of different amino acids in citrus plants, ACP adults, and nymphs, leading to a developmental pattern of ACP that is more conducive to CLas transmission.

19.
Commun Biol ; 4(1): 1331, 2021 11 25.
Artigo em Inglês | MEDLINE | ID: mdl-34824370

RESUMO

Huanglongbing (HLB) is a destructive disease of citrus primarily transmitted by the Asian citrus psyllid (ACP). Biocontrol of ACP is an environmentally sustainable alternative to chemicals. However, the risk of parasitoid rational application in ACP biocontrol has never been evaluated. Here we show, the dominant parasitoid of ACP, Tamarixia radiata, can acquire the HLB pathogen Candidatus Liberibacter asiaticus (CLas) and transmit it horizontally when probing ACP nymphs. If these ACP nymphs survive the probing, develop to adults and move to healthy plants, CLas can be transmitted to citrus leaves during feeding. We illustrate the formerly unrecognized risk that a parasitoid can potentially serve as a phoretic vector of the pathogen transmitted by its host, thus potentially diminishing some of the benefits it confers via biocontrol. Our findings present a significant caution to the strategy of using parasitoids in orchards with different infection status of insect-vectored pathogens.


Assuntos
Agentes de Controle Biológico , Citrus/microbiologia , Insetos Vetores/fisiologia , Liberibacter/fisiologia , Doenças das Plantas/microbiologia , Vespas/fisiologia , Animais , Feminino , Hemípteros/crescimento & desenvolvimento , Hemípteros/parasitologia , Ninfa/crescimento & desenvolvimento , Ninfa/parasitologia
20.
Ecotoxicol Environ Saf ; 220: 112334, 2021 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-34020284

RESUMO

Artificial light at night (ALAN) is a widespread environmental pollutant and stressor. Many nocturnal insects have been shown to experience ALAN stress. However, few studies have been conducted to uncover the mechanism by which nocturnal insects respond to ALAN stress. Previous studies suggest that lysine succinylation (Ksuc) is a potential mechanism that coordinates energy metabolism and antioxidant activity under stressful conditions. Mythimna separata (Walker) (M. separata) is a nocturnal insect that has been stressed by ALAN. In this study, we quantified the relative proteomic Ksuc levels in ALAN-stressed M. separata. Of the 466 identified Ksuc-modified proteins, 103 were hypersuccinylated/desuccinylated in ALAN-stressed moths. The hypersuccinylated/desuccinylated proteins were shown to be involved in various biological processes. In particular, they were enriched in metabolic processes, reactive oxygen species (ROS) homeostasis and the neuromuscular system. Furthermore, we demonstrated that Ksuc might affect moth locomotion by intervening with and coordinating these systems under ALAN stress. These findings suggest that Ksuc plays a vital role in the moth response to ALAN stress and moth locomotion behavior and provide a new perspective on the impact of ALAN on nocturnal insect populations and species communities.


Assuntos
Proteínas de Insetos/química , Luz , Iluminação , Lisina/química , Mariposas/fisiologia , Fototaxia , Proteoma/química , Animais , Antioxidantes/metabolismo , Metabolismo Energético , Estresse Fisiológico
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