Local Ecdysone synthesis in a wounded epithelium sustains developmental delay and promotes regeneration in Drosophila.

Regenerative ability often declines as animals mature past embryonic and juvenile stages, suggesting that regeneration requires redirection of growth pathways that promote developmental growth. Intriguingly, the Drosophila larval epithelia require the hormone ecdysone (Ec) for growth but require a drop in circulating Ec levels to regenerate. Examining Ec dynamics more closely, we find that transcriptional activity of the Ec-receptor (EcR) drops in uninjured regions of wing discs, but simultaneously rises in cells around the injury-induced blastema. In parallel, blastema depletion of genes encoding Ec biosynthesis enzymes blocks EcR activity and impairs regeneration but has no effect on uninjured wings. We find that local Ec/EcR signaling is required for injury-induced pupariation delay following injury and that key regeneration regulators upd3 and Ets21c respond to Ec levels. Collectively, these data indicate that injury induces a local source of Ec within the wing blastema that sustains a transcriptional signature necessary for developmental delay and tissue repair.

Molecular characterization and functional analysis of the ecdysone receptor isoform (EcR) from the oriental fruit moth Grapholita molesta (Lepidoptera: Tortricidae).

20-Hydroxyecdysone (20E) plays a vital role in a series of biological processes, via the nuclear receptors, EcR/USP by activating the ecdysone regulatory cascade. To clarify the role of EcR during the development of Grapholita molesta, the complementary DNA of ecdysone receptor isoform B1 (GmEcR-B1) was obtained from the transcriptome of G. molesta and verified by PCR. Alignment analysis revealed that the deduced protein sequence of GmEcR-B1 was highly homologous to EcR proteins identified in other lepidopteran species, especially the EcR-B1 isoform in Spodoptera litura. Quantitative real-time PCR showed that GmEcRs was expressed at all test developmental stages, and the expression level of GmEcRs was relatively higher during the period of the 3rd day of fifth instar larvae to 2nd of pupa than those in other stages. Moreover, the messenger RNA of GmEcRs was much more strongly expressed in the Malpighian tubule and epidermis than those in other tissues, which suggests that this gene may function in a tissue-specific manner during larval development. Silencing of GmEcRs could significantly downregulate the transcriptional level of ecdysone-inducible genes and result in increased mortality during metamorphosis and prolonged prepupal duration. Taken together, the present results indicate that GmEcRs may directly or indirectly affect the development of G. molesta.

Household chaos and parenting: The effect of household chaos does not depend on sensory-processing sensitivity and self-regulation.

Previous studies have found evidence for a causal effect of household chaos on parenting and suggest that this effect may be stronger for parents with higher sensory-processing sensitivity (SPS) or lower self-regulation. This study investigates whether primary caregivers of children around age 1.5-2 years show greater improvement in parenting after a decrease in household chaos if parents have higher SPS or lower self-regulation. The study employs a randomized controlled trial (RCT) design with an intervention aimed at reducing household chaos. A total of 125 parents of toddlers participated in the study. All participants were living in the Netherlands at the time of the study, 89% identified with the Dutch ethnicity and 11% with a non-Dutch ethnicity. Self-report as well as objective measures were used, including videotaped parent-child interactions and home observations. The effect of the intervention on parenting did not depend on SPS or self-regulation. When studying the relation between change in measures of household chaos and posttest parenting, decreased self-reported household chaos was related to less harsh discipline in parents with higher self-regulation, and to more harsh discipline in parents with lower self-regulation. However, this is a tentative finding that should be further explored in future research.

Estudios anteriores han encontrado evidencia de un efecto casual del caos en el hogar sobre la crianza y sugieren que este efecto pudiera ser más fuerte para progenitores con una más alta sensibilidad del proceso sensorial (SPS) o más baja autorregulación. Este estudio investiga si quienes primariamente cuidan a los niños de alrededor de 1.5-2 años muestran un más alto nivel de mejoras en la crianza después de una disminución en el caos del hogar si los progenitores poseen un alto nivel de SPS o baja autorregulación. El estudio emplea un diseño RCT con una intervención dirigida a reducir el caos en el hogar. En el estudio participaron 125 progenitores de niños pequeñitos. Todos los participantes vivían en Holanda al momento del estudio, 89% se identificaba con la etnicidad holandesa y 11% con una etnicidad no holandesa. Se usaron auto reportes, así como medidas de objetivos, incluyendo interacciones entre progenitor y niño grabadas en video y observaciones en casa. El efecto de la intervención sobre la crianza no dependió de SPS o de la autorregulación. Cuando se estudiaba la relación entre el cambio en las medidas del caos en el hogar y la crianza posterior a la prueba, la disminución del auto reportado caos en el hogar se relacionó con menos disciplina dura en progenitores con más alta autorregulación, así como con más disciplina dura en progenitores con más baja autorregulación. Sin embargo, se trata de un resultado tentativo que se debe explorar más en la futura investigación.

Des études précédentes ont trouvé peu de preuves à un effet de cause du chaos domestique sur le parentage et suggèrent que cet effet pourrait être plus fort pour les parents avec une sensibilité du traitement sensoriel (STS) plus élevée et une auto-régulation plus faible. Cette étude évalue si les personnes prenant soin des enfants autour de l'âge de 1,5-2 ans font preuve d'une plus grande amélioration dans le parentage avec moins de chaos domestique si les parents ont une STS plus élevée ou une autorégulation plus basse. Cette étude a employé un plan ECR avec une intervention destinée à réduire le chaos domestique. 125 parents de jeunes enfants ont participé à l'étude. Tous les participants vivaient aux Pays Bas au moment de l'étude, 89% s'identifiant comme d'ethnicité hollandaise et 11% d'ethnicité non hollandaise. Des auto-évaluations ainsi que des mesures objectives ont été utilisées, en utilisant des interactions parent-enfant filmées à la vidéo et des observations à domicile. L'effet de l'intervention sur le parentage n'a pas dépendu de la STS ou de l'auto-régulation. En étudiant la relation entre le changement dans les mesures de chaos domestique et de parentage posttest, le chaos autosignalé décru à une discipline moins sévère chez les parents avec une autorégulation plus élevée, et à une discipline plus sévère chez les parents avec une autorégulation moins élevée. Cependant c'est une constatation tentative qui devrait être explorée plus profondément dans des recherches futures.

Dpp-mediated TGF-ß signaling regulates vitellogenesis through 20-hydroxyecdysone signaling in the cabbage beetle, Colaphellus bowringi.

The Dpp signaling, as one of the branches within the TGF-ß superfamily, plays a crucial role in regulating various biological processes in insects. However, its impact on female reproduction through vitellogenesis remains unclear. In this study, the expression profiles implied that the Dpp signaling genes, including Dpp, Punt, Mad, and Medea, were up-regulated during reproductive development in the ovary of Colaphellus bowringi. Knockdown of these five Dpp signaling genes revealed significant effects of Dpp, Tkv, Mad, and Medea on ovarian development through vitellogenesis in the fat body. Our finding further indicated that Dpp signaling influences the expression of 20-hydroxyecdysone (20E) receptor and responsive genes in the fat body. Additionally, knockdown of 20E receptor EcR resulted in similar phenotypes as observed in the Dpp pathway genes knockdown, implying a regulatory role for Dpp signaling via EcR in vitellogenesis. Furthermore, knocking down Dpp, Tkv, and EcR in female adults led to a reduction in total dry weight and protein content, as well as the expression of mTOR, a factor linked to protein intake. These results suggest that the Dpp signaling pathway modulates vitellogenesis by impacting the AA/TOR-mediated 20E pathway in the fat body, providing novel insights into the network governing insect reproduction and offering potential targets for controlling female pest reproduction.

Transcription Factor TaMYB30 Activates Wheat Wax Biosynthesis.

The waxy cuticle covers a plant's aerial surface and contributes to environmental adaptation in land plants. Although past decades have seen great advances in understanding wax biosynthesis in model plants, the mechanisms underlying wax biosynthesis in crop plants such as bread wheat remain to be elucidated. In this study, wheat MYB transcription factor TaMYB30 was identified as a transcriptional activator positively regulating wheat wax biosynthesis. The knockdown of TaMYB30 expression using virus-induced gene silencing led to attenuated wax accumulation, increased water loss rates, and enhanced chlorophyll leaching. Furthermore, TaKCS1 and TaECR were isolated as essential components of wax biosynthetic machinery in bread wheat. In addition, silencing TaKCS1 and TaECR resulted in compromised wax biosynthesis and potentiated cuticle permeability. Importantly, we showed that TaMYB30 could directly bind to the promoter regions of TaKCS1 and TaECR genes by recognizing the MBS and Motif 1 cis-elements, and activate their expressions. These results collectively demonstrated that TaMYB30 positively regulates wheat wax biosynthesis presumably via the transcriptional activation of TaKCS1 and TaECR.

1,2-Dibenzoylhydrazine as a Multi-Inhibitor Compound: A Morphological and Docking Study.

In the framework of the multitarget inhibitor study, we report an in silico analysis of 1,2-dibenzoylhydrazine (DBH) with respect to three essential receptors such as the ecdysone receptor (EcR), urease, and HIV-integrase. Starting from a crystallographic structural study of accidentally harvested crystals of this compound, we performed docking studies to evaluate the inhibitory capacity of DBH toward three selected targets. A crystal morphology prediction was then performed. The results of our molecular modeling calculations indicate that DBH is an excellent candidate as a ligand to inhibit the activity of EcR receptors and urease. Docking studies also revealed the activity of DBH on the HIV integrase receptor, providing an excellent starting point for developing novel inhibitors using this molecule as a starting lead compound.

A Bayesian network-GIS probabilistic model for addressing human disturbance risk to ecological conservation redline areas.

Population growth and associated ecological space occupation are posing great risks to regional ecological security and social stability. In China, "Ecological Conservation Redline" (ECR) that prohibited urbanization and industrial construction has been proposed as a national policy to resolve spatial mismatches and management contradictions. However, unfriendly human disturbance activities (e.g., cultivation, mining, and infrastructure construction) still exist within the ECR, posing a great threat to ecological stability and safety. In this article, a Bayesian network (BN)-GIS probabilistic model is proposed to spatially and quantitatively address the human disturbance risk to the ECR at the regional scale. The Bayesian models integrate multiple human activities, ecological receptors of the ECR, and their exposure relationships for calculating the human disturbance risk. The case learning method geographic information systems (GIS) is then introduced to train BN models based on the spatial attribute of variables to evaluate the spatial distribution and correlation of risks. This approach was applied to the human disturbance risk assessment for the ECR that was delineated in 2018 in Jiangsu Province, China. The results indicated that most of the ECRs were at a low or medium human disturbance risk level, while some drinking water sources and forest parks in Lianyungang City possessed the highest risk. The sensitivity analysis result showed the ECR vulnerability, especially for cropland, that contributed most to the human disturbance risk. This spatially probabilistic method can not only enhance model's prediction precision, but also help decision-makers to determine how to establish priorities for policy design and conservation interventions. Overall, it presents a foundation for later ECR adjustments as well as for human disturbance risk supervision and management at the regional scale.

Exfoliated 2D Layered and Nonlayered Metal Phosphorous Trichalcogenides Nanosheets as Promising Electrocatalysts for CO2 Reduction.

Two-dimensional (2D) materials catalysts provide an atomic-scale view on a fascinating arena for understanding the mechanism of electrocatalytic carbon dioxide reduction (CO2 ECR). Here, we successfully exfoliated both layered and nonlayered ultra-thin metal phosphorous trichalcogenides (MPCh3 ) nanosheets via wet grinding exfoliation (WGE), and systematically investigated the mechanism of MPCh3 as catalysts for CO2 ECR. Unlike the layered CoPS3 and NiPS3 nanosheets, the active Sn atoms tend to be exposed on the surfaces of nonlayered SnPS3 nanosheets. Correspondingly, the nonlayered SnPS3 nanosheets exhibit clearly improved catalytic activity, showing formic acid selectivity up to 31.6 % with -7.51 mA cm-2 at -0.65 V vs. RHE. The enhanced catalytic performance can be attributed to the formation of HCOO* via the first proton-electron pair addition on the SnPS3 surface. These results provide a new avenue to understand the novel CO2 ECR mechanism of Sn-based and MPCh3 -based catalysts.

Comparison of imaging modalities in the diagnosis of external cervical resorption (ECR): an in-vitro study.

External cervical resorption is a pathological condition affecting the cervical margins of teeth. Due to the increased prevalence and the area it affects, it can be easily misdiagnosed. The ability of clinicians to diagnose ECR and subcategorise the lesions using periapical radiographs and cone beam-CT scans has not been investigated in-depth. This study aims to assess if diagnostic ability to detect ECR lesions with the two modalities was different and if there was a change in the diagnosis when CBCT was used. A human skull, including the mandible was used for this study. The teeth were randomly allocated to the different subcategories, then pre and post-preparation radiographs with CBCT were taken. Statistical analysis was done using IBM SPSS version 16.0 (SPSS Inc., Chicago, IL, USA). The study sample was composed of 60 participants, the overall sensitivity of intraoral radiographs was significantly lower than CBCT. When the participants were told the radiograph and the CBCT were of the same tooth 60% said they would change their diagnosis. The use of intraoral radiographs alone might not be enough to identify and correctly diagnose ECR lesions. CBCT can give a better idea about the nature and the extent of the lesion.

Steroid signaling in mature follicles is important for Drosophila ovulation.

Although ecdysteroid signaling regulates multiple steps in oogenesis, it is not known whether it regulates Drosophila ovulation, a process involving a matrix metalloproteinase-dependent follicle rupture. In this study, we demonstrated that ecdysteroid signaling is operating in mature follicle cells to control ovulation. Moreover, knocking down shade (shd), encoding the monooxygenase that converts ecdysone (E) to the more active 20-hydroxyecdysone (20E), specifically in mature follicle cells, blocked follicle rupture, which was rescued by ectopic expression of shd or exogenous 20E. In addition, disruption of the Ecdysone receptor (EcR) in mature follicle cells mimicked shd-knockdown defects, which were reversed by ectopic expression of EcR.B2 but not by EcR.A or EcR.B1 isoforms. Furthermore, we showed that ecdysteroid signaling is essential for the proper activation of matrix metalloproteinase 2 (Mmp2) for follicle rupture. Our data strongly suggest that 20E produced in follicle cells before ovulation activates EcR.B2 to prime mature follicles to be responsive to neuronal ovulatory stimuli, thus providing mechanistic insights into steroid signaling in Drosophila ovulation.

Hyperspectral Leaf Image-Based Cucumber Disease Recognition Using the Extended Collaborative Representation Model.

Collaborative representation (CR)-based classification has been successfully applied to plant disease recognition in cases with sufficient training samples of each disease. However, collecting enough training samples is usually time consuming and labor-intensive. Moreover, influenced by the non-ideal measurement environment, samples may be corrupted by variables introduced by bad illumination and occlusions of adjacent leaves. Consequently, an extended collaborative representation (ECR)-based classification model is presented in this paper. Then, it is applied to cucumber leaf disease recognition, which constructs a pure spectral library consisting of several representative samples for each disease and designs a universal variation spectral library that deals with linear variables superimposed on samples. Thus, each query sample is encoded as a linear combination of atoms from these two spectral libraries and disease identity is determined by the disease of minimal reconstruction residuals. Experiments are conducted on spectral curves extracted from normal leaves and the disease lesions of leaves infected with cucumber anthracnose and brown spot. The diagnostic accuracy is higher than 94.7% and the average online diagnosis time is short, about 1 to 1.3 ms. The results indicate that the ECR-based classification model is feasible in the fast and accurate diagnosis of cucumber leaf diseases.

Viability of power distribution in India - Challenges and Way Forward.

Energy is a key component for economic growth as well as for human development. India is the third-ranking electricity generator in the world but ranks 106th in terms of per capita consumption. Specifically, the distribution of power is the most important link in the value chain of the power sector since it is the cash register for the entire sector. In India, electricity is a concurrent subject shared between the Central and State Governments. While the generation of power has been deregulated since 2003, the supply of power to the consumers is generally carried out by Government-owned power Distribution Companies (DISCOMs). In this paper, the authors analyze the financial distress of DISCOMs in India, and explain how the supply-demand mismatch due to over-ambitious demand projections, the fixed and energy charges of thermal power plants, and the excess procurement of "must-run" renewable sources together contribute to the high cost of power procurement that drives the financial stress faced by DISCOMs. The authors support their assertion with a study of nine DISCOMs supplying electricity to 155 million people in three States and propose policy recommendations for a turnaround of such DISCOMs which can be rolled out with suitable modifications across India.

Molecular Mechanisms of Wing Polymorphism in Insects.

Many insects are capable of developing into either long-winged or short-winged (or wingless) morphs, which enables them to rapidly match heterogeneous environments. Thus, the wing polymorphism is an adaptation at the root of their ecological success. Wing polymorphism is orchestrated at various levels, starting with the insect's perception of environmental cues, then signal transduction and signal execution, and ultimately the transmitting of signals into physiological adaption in accordance with the particular morph produced. Juvenile hormone and ecdysteroid pathways have long been proposed to regulate wing polymorphism in insects, but rigorous experimental evidence is lacking. The breakthrough findings of ecdysone receptor regulation on transgenerational wing dimorphism in the aphid Acyrthosiphon pisum and of insulin signaling in the planthopper Nilaparvata lugens greatly broaden our understanding of wing polymorphism at the molecular level. Recently, the advent of high-throughput sequencing coupled with functional genomics provides powerful genetic tools for future insights into the molecular bases underlying wing polymorphism in insects.

A distal 594†bp ECR specifies Hmx1 expression in pinna and lateral facial morphogenesis and is regulated by the Hox-Pbx-Meis complex.

Hmx1 encodes a homeodomain transcription factor expressed in the developing lateral craniofacial mesenchyme, retina and sensory ganglia. Mutation or mis-regulation of Hmx1 underlies malformations of the eye and external ear in multiple species. Deletion or insertional duplication of an evolutionarily conserved region (ECR) downstream of Hmx1 has recently been described in rat and cow, respectively. Here, we demonstrate that the impact of Hmx1 loss is greater than previously appreciated, with a variety of lateral cranioskeletal defects, auriculofacial nerve deficits, and duplication of the caudal region of the external ear. Using a transgenic approach, we demonstrate that a 594 bp sequence encompassing the ECR recapitulates specific aspects of the endogenous Hmx1 lateral facial expression pattern. Moreover, we show that Hoxa2, Meis and Pbx proteins act cooperatively on the ECR, via a core 32 bp sequence, to regulate Hmx1 expression. These studies highlight the conserved role for Hmx1 in BA2-derived tissues and provide an entry point for improved understanding of the causes of the frequent lateral facial birth defects in humans.

miR-34 regulates reproduction by inhibiting the expression of MIH, CHH, EcR, and FAMeT genes in mud crab Scylla paramamosain.

Mud crab Scylla paramamosain is a commercially important species widely cultured in China. It is well known that the eyestalk regulates reproductive activities in crustaceans. In our previous research, we found that the miR-34 expression level in male eyestalk was significantly higher than that in females. Thus, we assumed that it may play an important role in regulating reproduction. In this study, we used bioinformatic tools to identify the target genes of miR-34 in eyestalk. Six reproduction-related genes with an intact 3'-untranslated region (UTR), including molt-inhibiting hormone (MIH), crustacean hyperglycemic hormone (CHH), vitellogenesis-inhibiting hormone, red pigment concentrating hormone, ecdysone receptor (EcR), and farnesoic acid methyltransferase (FAMeT) were identified. When the 3'-UTR plasmid vectors of the six genes were cotransfected with miR-34 mimics into 293FT cells, respectively, the luciferase activities of four genes (MIH, CHH, EcR, and FAMeT) were significantly decreased compared with that in the control group; on the contrary, when the six plasmid vectors were cotransfected with the miR-34 inhibitor respectively, the luciferase activities of four genes (MIH, CHH, EcR, and FAMeT) were significantly higher than that in the control group. When agomiR-34 and antagomiR-34 were injected into the eyestalk respectively in vivo, the expression levels of the MIH, CHH, EcR, and FAMeT genes were detected by a quantitative real-time polymerase chain reaction. The results showed that agomiR-34 suppressed the expression of the four genes, whereas antagomiR-34 enhanced their expression. These experimental results confirmed our hypothesis that miR-34 may indirectly regulate reproduction via binding to the 3'-UTRs of MIH, CHH, EcR, and FAMeT genes and suppressing their expression.

A Fast, Three-Dimensional, Indirect Geolocation Method Using IAGM and DSM Data without GCPs for Spaceborne SAR Images.

To determine the geolocation of a pixel for spaceborne synthetic aperture radar (SAR) images, traditional indirect geolocation methods can cause great computational complexity. In this paper, a fast, three-dimensional, indirect geolocation method without ground control points (GCPs) is presented. First, the Range-Doppler (RD) geolocation model with all the equations in the Earth-centered rotating (ECR) coordinate system is introduced. By using an iterative analytical geolocation method (IAGM), the corner point locations of a quadrangle SAR image on the Earth's surface are obtained. Then, a three-dimensional (3D) grid can be built by utilizing the digital surface model (DSM) data in this quadrangle. Through the proportional relationship for every pixel in the 3D grid, the azimuth time can be estimated, which is the key to decreasing the calculation time of the Doppler centroid. The results show that the proposed method is about 12 times faster than the traditional method, and that it maintains geolocation accuracy. After acquiring the precise azimuth time, it is easy to obtain the range location. Therefore, the spaceborne SAR image can be geolocated to the Earth surface precisely based on the high-resolution DSM data.

[Inhibitory effect of extract of Coptidis Rhizoma on invasion of Candida albicans hyphae in vitro].

The aim of this paper was to investigate the inhibitory effect of extract of Coptidis Rhizoma(ECR) on invasion of Candida albicans hyphae in vitro.XTT reduction method was used to evaluate the metabolic activity of C.albicans.The colony edge growth of C.albicans was observed by solid medium.The growth of C.albicans hyphae was determined on semi-solid medium.The morphology and viability changes of C.albicans hyphae were assessed by scanning electron microscope and fluorescence microscope.qRT-PCR method was used to detect the ALS3 and SSA1 expression of C.albicans invasin genes.The results showed that the metabolic viability by XTT method detected that the activity of C.albicans was gradually decreased under the intervention of 64,128 and 256 mg·L-1 of ECR respectively.128,256 mg·L-1 of ECR significantly inhibited colony folds and wrinkles on solid medium and the hyphal invasion in semi-solid medium.Scanning electron microscopy and fluorescence microscopy showed that 128,256 mg·L-1 of ECR could inhibit the formation of C.albicans hyphae.qRT-PCR results showed that the expression of invasin gene ALS3 and SSA1 was down-regulated,and especially 256 mg·L-1 of ECR could down-regulate the two genes expression by 4.8,1.68 times respectively.This study showed that ECR can affect the invasiveness of C.albicans by inhibiting the growth of hyphae and the expression of invasin.

Reliability and validity of the Experiences in Close Relationships Scale-12: Attachment dimensions in a clinical sample with eating disorders.

OBJECTIVE: Attachment insecurity is a potential risk factor for the development and maintenance of eating disorders (EDs). To date, there are multiple psychometrically sound questionnaires for the evaluation of attachment in both clinical and healthy populations, such as the Experience in Close Relationships (ECR) scale. Composed by two subscales (i.e., attachment anxiety and avoidance), the ECR scale was recently adapted to a shorter, 12-item version (ECR-12). However, a validation of the ECR-12 among patients with EDs is still lacking. The present study sought to investigate the psychometric properties of the ECR-12, when used in a treatment-seeking sample with EDs. METHOD: A total of 1,262 treatment-seeking patients with various ED diagnoses completed the ECR-12, together with a commonly used measure of ED psychopathology (Eating Disorder Inventory-2). Subsamples also completed the Attachment Style Questionnaire (n = 66) or underwent a Day Hospital Program (n = 128). RESULTS: A multigroup confirmatory factor analysis indicated that the ECR-12 maintained its two-factor structure across the ED diagnostic groups. In addition, the scale demonstrated good convergent validity, internal consistency, concurrent, and incremental validity. Finally, both ECR-12 subscales demonstrated adequate test-retest reliability. DISCUSSION: Our results provide preliminary evidence of the psychometric properties of ECR-12 in assessing attachment anxiety and avoidance among patients with EDs. This short scale could help clinicians tailor interventions for EDs that take into account attachment dimensions.

The ecdysone receptor signalling regulates microvilli formation in follicular epithelial cells.

Epithelial morphogenesis contributes greatly to the development and homeostasis of the organs and body parts. Here, we analysed the consequences of impaired ecdysone receptor (EcR) signalling in the Drosophila follicular epithelium. Besides governing cell growth, the three EcR isoforms act redundantly in controlling follicle cell positioning. Flattening of the microvilli and an aberrant actin cytoskeleton arise from defective EcR signalling in follicle cells, and these defects impact on the organisation of the oocyte membrane. We found that this signalling governs a complex molecular network since its impairment affects key molecules as atypical protein kinase C and activated Moesin. Interestingly, the activity of the transcription factor Tramtrack69 isoform is required for microvilli and their actin core morphogenesis as well as for follicle cell positioning. In conclusion, our findings provide evidence of novel roles for EcR signalling and Tramtrack69 transcription factor in controlling stage-specific differentiation events that take place in the follicular epithelium.

Identification and expression of nuclear receptor genes and ecdysteroid titers during nymphal development in the spider Agelena silvatica.

Ecdysteroids play an essential role in the regulation of the molting processes of arthropods. Nuclear receptors of the spider Agelena silvatica that showed high homology with other arthropods especially in the functional domains were identified, two isoforms of ecdysone receptor (AsEcRA, AsEcRB), retinoid X receptor (AsRXR) and two isoforms of E75 (AsE75A, AsE75D). AsEcR and AsRXR mRNA did not show major changes in expression but occurred throughout the third instar nymphal stage. AsE75DBD was low or non-existent at first then showed a sudden increase from D7 to D10. On the other hand, AsE75D was expressed in the first half and decreased from D6 to D10. Ecdysteroid titers showed a peak on D6 in A. silvatica third instar nymphs. LC-MS/MS analysis of the ecdysteroid peak revealed only 20-hydroxyecdysone (20E) was present. The 20E peak on D6 and increase in AsE75DBD from D7 is likely a result of ecdysteroids binding to the heterodimer formed with constant expression of the AsEcR and AsRXR receptors. These findings indicate the mechanisms regulating molting widely conserved in insects and other arthropods also similarly function in spiders.