Phenotypic plasticity, global change, and the speed of adaptive evolution

International audienc

Dynamique de l'or et d'autres minéraux lourds dans un profil d'altération cuirassé du Burkina Faso, Afrique de l'Ouest : intérêt pour l'interprétation de la mise en place des matériaux constituant les cuirasses de haut glacis

Le profil d'altération cuirassé de haut glacis, développé dans l'environnement du site aurifère de Gangaol, a subi des phases d'altération suffisamment intenses pour que des minéraux résistants, comme le zircon et l'or, présentent des traces de dissolution importantes. Dans l'horizon supérieur de la cuirasse, ces minéraux altérés coexistent avec des particules d'or conservant des formes primaires intactes et avec des sulfures sains. Au sein de cet horizon, les teneurs en particules d'or sont plus élevées dans la matrice que dans les nodules fortement indurés. Cela implique qu'à ce niveau, le cuirassement a affecté un matériau contenant des éléments de nature et de degré d'altération variés. L'absence d'or dans la partie médiane du profil confirme un certain degré d'allochtonie des matériaux parentaux de l'horizon supérieur de la cuirasse. (Résumé d'auteur

Grapevine virus L: a novel vitivirus in grapevine

Vitiviruses are ssRNA(+) viruses in the family Betaflexiviridae (subfamily Trivirinae). There are currently 10 ICTV recognized virus species in the genus; nevertheless, the extended use of NGS technologies is rapidly expanding their diversity and official recognition of six more have been proposed recently. Here, we present the characterization of a novel virus from grapevine, which fits the genomic architecture and evolutionary constraints to be classified within the Vitivirus genus. The detected virus sequence is 7607 nt long, including a typical genome organization of ORFs encoding a replicase (RP), a 22 kDa protein, a movement protein, a coat protein (CP) and a nucleic acid binding protein. Phylogenetic analyses based on the predicted RP and CP proteins unequivocally place the new virus within the Vitivirus genus. Multiple independent RNAseq data confirmed the presence of the detected virus in berries at diverse developmental stages. Additionally, we detected, confirmed, and assembled virus sequences from grapevine samples of distinct cultivars from America, Europe, Asia and Oceania, sharing 74.4%–97.8% nt identity, suggesting that the identified virus is widely distributed and diverse. We propose the name grapevine virus L (GVL) to the detected Vitivirus.Fil: Debat, Humberto Julio. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigaciones Agropecuarias. Instituto de Patología Vegetal; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Zavallo, Diego. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación En Ciencias Veterinarias y Agronómicas. Instituto de Agrobiotecnología y Biología Molecular. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Agrobiotecnología y Biología Molecular; ArgentinaFil: Soltero Brisbane, Reid. Foundation Plant Services; Estados UnidosFil: Voncina, Darko. University of Zagreb; CroaciaFil: Almeida, Rodrigo P.. University of California at Berkeley; Estados UnidosFil: Blouin, Arnaud G.. No especifíca;Fil: Al Rwahnih, Maher. University of California at Berkeley; Estados UnidosFil: Gómez Talquenca, Sebastián. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Mendoza-San Juan. Estación Experimental Agropecuaria Mendoza; ArgentinaFil: Asurmendi, Sebastian. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación En Ciencias Veterinarias y Agronómicas. Instituto de Agrobiotecnología y Biología Molecular. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Agrobiotecnología y Biología Molecular; Argentin

Stressful conditions reveal decrease in size, modification of shape but relatively stable asymmetry in bumblebee wings

Human activities can generate a wide variety of direct and indirect effects on animals, which can manifest as environmental and genetic stressors. Several phenotypic markers have been proposed as indicators of these stressful conditions but have displayed contrasting results, depending, among others, on the phenotypic trait measured. Knowing the worldwide decline of multiple bumblebee species, it is important to understand these stressors and link them with the drivers of decline. We assessed the impact of several stressors (i.e. natural toxin-, parasite-, thermic- and inbreeding-stress) on both wing shape and size and their variability as well as their directional and fluctuating asymmetries. The total data set includes 650 individuals of Bombus terrestris (Hymenoptera: Apidae). Overall wing size and shape were affected by all the tested stressors. Except for the sinigrin (e.g. glucosinolate) stress, each stress implies a decrease of wing size. Size variance was affected by several stressors, contrary to shape variance that was affected by none of them. Although wing size directional and fluctuating asymmetries were significantly affected by sinigrin, parasites and high temperatures, neither directional nor fluctuating shape asymmetry was significantly affected by any tested stressor. Parasites and high temperatures led to the strongest phenotype modifications. Overall size and shape were the most sensitive morphological traits, which contrasts with the common view that fluctuating asymmetry is the major phenotypic marker of stress

Enhanced flight performance by genetic manipulation of wing shape in Drosophila

Insect wing shapes are remarkably diverse and the combination of shape and kinematics determines both aerial capabilities and power requirements. However, the contribution of any specific morphological feature to performance is not known. Using targeted RNA interference to modify wing shape far beyond the natural variation found within the population of a single species, we show a direct effect on flight performance that can be explained by physical modelling of the novel wing geometry. Our data show that altering the expression of a single gene can significantly enhance aerial agility and that the Drosophila wing shape is not, therefore, optimized for certain flight performance characteristics that are known to be important. Our technique points in a new direction for experiments on the evolution of performance specialities in animals

Environmental Stress-Dependent Effects of Deletions Encompassing Hsp70Ba on Canalization and Quantitative Trait Asymmetry in Drosophila melanogaster

Hsp70 genes may influence the expression of wing abnormalities in Drosophila melanogaster but their effects on variability in quantitative characters and developmental instability are unclear. In this study, we focused on one of the six Hsp70 genes, Hsp70Ba, and investigated its effects on within-and among-individual variability in orbital bristle number, sternopleural bristle number, wing size and wing shape under different environmental conditions. To do this, we studied a newly constructed deletion, Df(3R)ED5579, which encompasses Hsp70Ba and nine non-Hsp genes, in the heterozygous condition and another, Hsp70Ba304, which deletes only Hsp70Ba, in the homozygous condition. We found no significant effect of both deletions on within-individual variation quantified by fluctuating asymmetry (FA) of morphological traits. On the other hand, the Hsp70Ba304/Hsp70Ba304 genotype significantly increased among-individual variation quantified by coefficient of variation (CV) of bristle number and wing size in female, while the Df(3R)ED5579 heterozygote showed no significant effect. The expression level of Hsp70Ba in the deletion heterozygote was 6 to 20 times higher than in control homozygotes, suggesting that the overexpression of Hsp70Ba did not influence developmental stability or canalization significantly. These findings suggest that the absence of expression of Hsp70Ba increases CV of some morphological traits and that HSP70Ba may buffer against environmental perturbations on some quantitative traits

A Single Basis for Developmental Buffering of Drosophila Wing Shape

The nature of developmental buffering processes has been debated extensively, based on both theoretical reasoning and empirical studies. In particular, controversy has focused on the question of whether distinct processes are responsible for canalization, the buffering against environmental or genetic variation, and for developmental stability, the buffering against random variation intrinsic in developmental processes. Here, we address this question for the size and shape of Drosophila melanogaster wings in an experimental design with extensively replicated and fully controlled genotypes. The amounts of variation among individuals and of fluctuating asymmetry differ markedly among genotypes, demonstrating a clear genetic basis for size and shape variability. For wing shape, there is a high correlation between the amounts of variation among individuals and fluctuating asymmetry, which indicates a correspondence between the two types of buffering. Likewise, the multivariate patterns of shape variation among individuals and of fluctuating asymmetry show a close association. For wing size, however, the amounts of individual variation and fluctuating asymmetry are not correlated. There was a significant link between the amounts of variation between wing size and shape, more so for fluctuating asymmetry than for variation among individuals. Overall, these experiments indicate a considerable degree of shared control of individual variation and fluctuating asymmetry, although it appears to differ between traits

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Abstract:  The study of the SARS-CoV-2 genome allows to evaluate its evolutionary pattern, identify mutations, lineages and variants that may have an impact on public health. Variants of concern (VOC) and variants of interest (VOI), which have different biological characteristics, have been identified worldwide. The objective of this work is to describe the lineages and variants of SARS-CoV-2 circulating in Córdoba using different strategies. Three strategies were implemented from positive SARS-CoV-2 RNA samples (Cts<30): 1)-whole genome sequencing (WGS) (ONT-MinION): 203 samples analysed from March 2020 to June 2021; 2)-partial sequencing of the Spike protein gene (Sanger): 54 samples analysed between February and April 2021 of travellers from abroad; and 3)-real time RT-PCR for detection of relevant VOC mutations (TaqMan™ SARS-CoV-2 Mutation Panel, Applied Biosystems): 816 samples analysed between May and June 2021.   Results were the following: 1)-circulation of 7 lineages with a greater predominance of B.1.1.33.3 (N3) (40.5%) and B.1.499 (38.8%), between March 2020 and January 2021; and circulation of 12 lineages with presence of VOC [P.1 (Gamma, 28.4%), B.1.1.7 (Alpha, 6.9%)] and VOI [C.37 (Lambda, 20.6%), B.1.427 (Epsilon, 10.8%), P2 (Zeta, 2.9%), B.1.526 (Iota, 2%)], between February and June 2021; 2)-presence of VOC Alpha (26.4%) and Gamma (17%), and samples compatible with VOI Epsilon and Zeta; 3)-presence of VOC Gamma (56%) and Alpha (11%), and other variants which could not be typified by this methodology. Results show the circulation of many SARS-CoV-2 lineages in Córdoba, which varied their distribution over time, according to the different introductions occurred, the population movement and the evolutionary advantages of some variants over others. In March 2021, the first VOC detections were realized in the province (Alpha and Gamma), being Gamma the one that mostly circulates at present. Although the WGS is the technique which provides more information, the other 2 strategies implemented were and are very useful tools for molecular epidemiological surveillance, obtaining the information in real time. Strategy 3 is a simpler, faster and more operative tool for molecular VOC screening.Resumen:  El estudio del genoma de SARS-CoV-2 permite evaluar su dinámica evolutiva, identificar mutaciones, linajes y variantes que puedan impactar en la salud pública. A nivel mundial se identificaron variantes de preocupación (VOC) y variantes de interés (VOI), que presentan características biológicas diferentes. El objetivo del trabajo es describir los linajes y variantes de SARS-CoV-2 circulantes en Córdoba mediante tres estrategias. Se implementaron 3 estrategias, a partir de muestras de RNA positivas para el virus (Cts<30): 1)-secuenciación de genoma completo (ONT-MinION): 203 muestras analizadas desde marzo 2020 a junio 2021; 2)-secuenciación de un fragmento genómico de la proteína S (Sanger): 54 muestras analizadas entre febrero y abril 2021 en viajeros provenientes del exterior; y 3)-PCR en tiempo real para detección de VOC (TaqMan™ SARS-CoV-2 Mutation Panel, Applied Biosystems): 816 muestras analizadas entre mayo y junio de 2021.       Los resultados fueron: 1)-circulación de siete linajes con mayor predominancia de B.1.1.33.3 (N3) (40,5%) y B.1.499 (38,8%), entre marzo 2020 y enero 2021; y circulación de 12 linajes con presencia de VOC [P.1 (Gamma, 28,4%), B.1.1.7 (Alpha, 6,9%)] y VOI [C.37 (Lambda, 20,6%), B.1.427 (Epsilon, 10,8%), P2 (Zeta, 2,9%), B.1.526 (Iota, 2%)], entre febrero y junio 2021; 2)-presencia de VOC Alpha (26,4%) y Gamma (17%), y muestras compatibles con las VOI Epsilon y Zeta (9,4%); 3)-presencia de VOC Gamma (56%) y Alpha (11%), y otras variantes no tipificables por esta metodología. Los resultados muestran circulación de diversos linajes de SARS-CoV-2 en Córdoba, que variaron su distribución a lo largo del tiempo, según las distintas introducciones ocurridas, el movimiento poblacional y las ventajas evolutivas de unos sobre otros. En marzo 2021 se realizaron las primeras detecciones de VOC en la provincia (Alpha y Gamma), siendo la variante Gamma la que circula mayoritariamente en la actualidad. Si bien la secuenciación del genoma completo es la técnica que mayor información brinda, las otras 2 estrategias implementadas fueron y son de gran utilidad para la vigilancia epidemiológica molecular, favoreciendo la obtención de información en tiempo real. La estrategia 3 resulta una herramienta más simple, rápida y con mayor capacidad operativa para el screening molecular de VOC.

The Effect of Genetic and Environmental Variation on Genital Size in Male Drosophila: Canalized but Developmentally Unstable

The genitalia of most male arthropods scale hypoallometrically with body size, that is they are more or less the same size across large and small individuals in a population. Such scaling is expected to arise when genital traits show less variation than somatic traits in response to factors that generate size variation among individuals in a population. Nevertheless, there have been few studies directly examining the relative sensitivity of genital and somatic traits to factors that affect their size. Such studies are key to understanding genital evolution and the evolution of morphological scaling relationships more generally. Previous studies indicate that the size of genital traits in male Drosophila melanogaster show a relatively low response to variation in environmental factors that affect trait size. Here we show that the size of genital traits in male fruit flies also exhibit a relatively low response to variation in genetic factors that affect trait size. Importantly, however, this low response is only to genetic factors that affect body and organ size systemically, not those that affect organ size autonomously. Further, we show that the genital traits do not show low levels of developmental instability, which is the response to stochastic developmental errors that also influence organ size autonomously. We discuss these results in the context of current hypotheses on the proximate and ultimate mechanisms that generate genital hypoallometry

Leaf Morphology, Taxonomy and Geometric Morphometrics: A Simplified Protocol for Beginners

Taxonomy relies greatly on morphology to discriminate groups. Computerized geometric morphometric methods for quantitative shape analysis measure, test and visualize differences in form in a highly effective, reproducible, accurate and statistically powerful way. Plant leaves are commonly used in taxonomic analyses and are particularly suitable to landmark based geometric morphometrics. However, botanists do not yet seem to have taken advantage of this set of methods in their studies as much as zoologists have done. Using free software and an example dataset from two geographical populations of sessile oak leaves, we describe in detailed but simple terms how to: a) compute size and shape variables using Procrustes methods; b) test measurement error and the main levels of variation (population and trees) using a hierachical design; c) estimate the accuracy of group discrimination; d) repeat this estimate after controlling for the effect of size differences on shape (i.e., allometry). Measurement error was completely negligible; individual variation in leaf morphology was large and differences between trees were generally bigger than within trees; differences between the two geographic populations were small in both size and shape; despite a weak allometric trend, controlling for the effect of size on shape slighly increased discrimination accuracy. Procrustes based methods for the analysis of landmarks were highly efficient in measuring the hierarchical structure of differences in leaves and in revealing very small-scale variation. In taxonomy and many other fields of botany and biology, the application of geometric morphometrics contributes to increase scientific rigour in the description of important aspects of the phenotypic dimension of biodiversity. Easy to follow but detailed step by step example studies can promote a more extensive use of these numerical methods, as they provide an introduction to the discipline which, for many biologists, is less intimidating than the often inaccessible specialistic literature