Biology subjects

Magro, A.

Publications and source records attributed to Magro, A..

6 recordsLinked to original sources

bioRxiv2026

Wolbachia facilitates the reproduction of a parthenogenetic ladybug

Wolbachia is a bacterial endosymbiont that is primarily transmitted from mother to offspring. To increase their transmission, some strains manipulate their hosts reproduction to favor female offspring, such as by inducing parthenogenesis. Here, we assess whether Wolbachia induces parthenogenesis in recently discovered parthenogenetic populations of the ladybug Nephus voeltzkowi by treating females with an antibiotic. Females from sexual populations, which we show are not infected by Wolbachia, serve as a control. Our results demonstrate that the treatment decreases Wolbachia load, subsequently reducing egg production and development among parthenogenetic females, while having no effect on sexual females. Wolbachia load and reproduction then rebound when the treatment is removed. This suggests that the Wolbachia infection is necessary for successful reproduction in the parthenogenetic females, and it may play a two-part role by facilitating egg laying and late embryo development. The cooccurrence of Wolbachia infection and parthenogenesis in N. voeltzkowi, as well as Wolbachias manipulation of host reproduction makes this a likely candidate of Wolbachia-induced parthenogenesis outside of haplo-diploids. Understanding how Wolbachia can impact diverse insect reproductive systems can shed a light on the extent in which these bacteria can manipulate hosts for their own gain.

evolutionary biology↗

bioRxiv2026

Edge effect on the distribution of the Green Shield Bug Palomena prasina in hazelnut orchards, and the role of adjacent habitats in crop colonization.

Palomena prasina (L.) (Hemiptera: Pentatomidae), the green shield bug (GSB), is an important hazelnut pest in Southern Europe. Currently, its control focuses on insecticide spraying during the crop season. We hypothesised that, as for other pentatomid species, adjacent habitats strongly influence the population build-up in spring and, therefore, lead to edge effects in crop fields during the production season. This could allow for precision-targeted pest management strategies. This study examined the spatio-temporal dynamics of the GSB in spring and summer over two years. We investigated the plant preferences of GSBs in spring and the existence of edge effects on their distribution and on fruit damage in hazelnut orchards in summer. We also examined the relative contribution of adjacent habitats to GSB abundance in crops. Our results show that, following their emergence from overwintering in spring, GSB adults, and later on their offspring, are primarily found on wild host plants in natural habitats, particularly on Crataegus monogyna Jacquin, and Cornus sanguinea L.. In early summer, the older nymphs of the second generation colonise the hazelnut orchards, with populations and damage proportion displaying edge effects. We were unable to identify an adjacent habitat variable that significantly explains the abundance of GSB in the orchards, although both forest habitats and hazelnut orchards have an effect on GSB abundance. Based on these findings, we propose various IPM strategies for controlling P. prasina.

ecology↗

bioRxiv2025

Decoding ladybird's colours: structural mechanisms of colour production and pigment modulation.

This study investigates the mechanisms underlying colour production in the family Coccinellidae, focusing on two model species: A. bipunctata (L) and C. quatuordecimguttata (L). In this family, colours have traditionally been attributed primarily to pigments such as carotenoids and melanins. We propose an alternative perspective, considering the elytra as an integrated optical medium whose optical properties result from both its architectural design and the properties of its constituent materials, including matrix and pigments. In the present work, several methods were used, ranging from optical and electron microscopies, light-based techniques, to LC-HRMS analyses. Through local pigment analyses, microstructural examination of elytra, and modelling of interaction of elytra with light, we show that, while pigments are central to patterning and contribute to colour, overall colour also results from one or more physical mechanisms that may operate simultaneously. In the light of these results, we assume that the complex and diverse colouration in the Coccinellidae can only be elucidated by considering the interplay of pigments and the optical properties of the elytron cuticle.

evolutionary biology↗

bioRxiv2024

Point mutations of the mitochondrial chaperone TRAP1 affect its functions and pro-neoplastic activity.

The mitochondrial chaperone TRAP1 is a key regulator of cellular homeostasis and its activity has important implications in neurodegeneration, ischemia and cancer. Recent evidence has indicated that TRAP1 mutations are involved in several disorders, even though the structural basis for the impact of point mutations on TRAP1 functions has never been studied. By exploiting a modular structure-based framework and molecular dynamics simulations, we investigated the effect of five TRAP1 mutations on its structure and stability. Each mutation differentially impacts long-range interactions, intra and inter-protomer dynamics and ATPase activity. Changes in these parameters influence TRAP1 functions, as revealed by their effects on the activity of the TRAP1 interactor succinate dehydrogenase (SDH). In keeping with this, TRAP1 point mutations affect the growth and migration of aggressive sarcoma cells, and alter sensitivity to a selective TRAP1 inhibitor. Our work provides new insights on the structure-activity relationship of TRAP1, identifying crucial amino acid residues that regulate TRAP1 proteostatic functions and pro-neoplastic activity.

cancer biology↗

bioRxiv2021

Unveiling Mutation Effects on the Structural Dynamics of the Main Protease from SARS-CoV-2 with Hybrid Simulation Methods

The main protease of SARS-CoV-2 (called Mpro or 3CLpro) is essential for processing polyproteins encoded by viral RNA. Macromolecules adopt several favored conformations in solution depending on their structure and shape, determining their dynamics and function. Integrated methods combining the lowest-frequency movements obtained by Normal Mode Analysis (NMA), and the faster movements from Molecular Dynamics (MD), and data from biophysical techniques, are necessary to establish the correlation between complex structural dynamics of macromolecules and their function. In this article, we used a hybrid simulation method to sample the conformational space to characterize the structural dynamics and global motions of WT SARS-CoV-2 Mpro and 48 mutants, including several mutations that appear in P.1, B.1.1.7, B.1.351, B.1.525 and B.1.429+B.1.427 variants. Integrated Hybrid methods combining NMA and MD have been useful to study the correlation between the complex structural dynamics of macromolecules and their functioning mechanisms. Here, we applied this hybrid approach to elucidate the effects of mutation in the structural dynamics of SARS-CoV-2 Mpro, considering their flexibility, solvent accessible surface area analyses, global movements, and catalytic dyad distance. Furthermore, some mutants showed significant changes in their structural dynamics and conformation, which could lead to distinct functional properties. HighlightsO_LISingle surface mutations lead to changes in Mpro structural dynamics. C_LIO_LIMutants can be more stable than WT according to the structural dynamics properties. C_LIO_LIMpromutants can present a distinct functionality in relation to the wild-type. C_LIO_LIPotential viral markers for more pathogenic or transmissible SARS-CoV-2 variants. C_LI

biophysics↗

bioRxiv2019

Herbivore intraspecific variation and evolutionary divergence drive trophic cascade strength

AO_SCPLOWBSTRACTC_SCPLOWTrophic cascades--the indirect effect of predators on non-adjacent lower trophic levels--are important drivers of the structure and dynamics of ecological communities. However, the influence of intraspecific trait variation on the strength of trophic cascade remains largely unexplored, which limits our understanding of the mechanisms underlying ecological networks. Here we experimentally investigated how intraspecific difference among herbivore lineages specialized on different host plants influences the strength of trophic cascade in a terrestrial tritrophic system. We found that the occurrence and strength of the trophic cascade are strongly influenced by herbivores lineage and host-plant specialization but are not associated with density-dependent effects mediated by the growth rate of herbivore populations. Our findings stress the importance of intraspecific heterogeneities and evolutionary specialization as drivers of the strength of trophic cascades and underline that intraspecific variation should not be overlooked to decipher the joint influence of evolutionary and ecological factors on the functioning of multi-trophic interactions.

ecology↗